^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * linux/fs/super.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 1991, 1992 Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * super.c contains code to handle: - mount structures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * - super-block tables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * - filesystem drivers list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * - mount system call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * - umount system call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * - ustat system call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * GK 2/5/95 - Changed to support mounting the root fs via NFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * Added kerneld support: Jacques Gelinas and Bjorn Ekwall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Added change_root: Werner Almesberger & Hans Lermen, Feb '96
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Added options to /proc/mounts:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/blkdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/security.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/writeback.h> /* for the emergency remount stuff */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/idr.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/backing-dev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/rculist_bl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/cleancache.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/fscrypt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/fsnotify.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/lockdep.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/user_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/fs_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <uapi/linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static int thaw_super_locked(struct super_block *sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) static LIST_HEAD(super_blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static DEFINE_SPINLOCK(sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) static char *sb_writers_name[SB_FREEZE_LEVELS] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) "sb_writers",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) "sb_pagefaults",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) "sb_internal",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * One thing we have to be careful of with a per-sb shrinker is that we don't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * drop the last active reference to the superblock from within the shrinker.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * If that happens we could trigger unregistering the shrinker from within the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * take a passive reference to the superblock to avoid this from occurring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) static unsigned long super_cache_scan(struct shrinker *shrink,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) struct shrink_control *sc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) long fs_objects = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) long total_objects;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) long freed = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) long dentries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) long inodes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) sb = container_of(shrink, struct super_block, s_shrink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * Deadlock avoidance. We may hold various FS locks, and we don't want
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * to recurse into the FS that called us in clear_inode() and friends..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (!(sc->gfp_mask & __GFP_FS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) return SHRINK_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (!trylock_super(sb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return SHRINK_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (sb->s_op->nr_cached_objects)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) fs_objects = sb->s_op->nr_cached_objects(sb, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) inodes = list_lru_shrink_count(&sb->s_inode_lru, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) dentries = list_lru_shrink_count(&sb->s_dentry_lru, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) total_objects = dentries + inodes + fs_objects + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) if (!total_objects)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) total_objects = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) /* proportion the scan between the caches */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) dentries = mult_frac(sc->nr_to_scan, dentries, total_objects);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) fs_objects = mult_frac(sc->nr_to_scan, fs_objects, total_objects);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * prune the dcache first as the icache is pinned by it, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * prune the icache, followed by the filesystem specific caches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * Ensure that we always scan at least one object - memcg kmem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * accounting uses this to fully empty the caches.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) sc->nr_to_scan = dentries + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) freed = prune_dcache_sb(sb, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) sc->nr_to_scan = inodes + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) freed += prune_icache_sb(sb, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if (fs_objects) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) sc->nr_to_scan = fs_objects + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) freed += sb->s_op->free_cached_objects(sb, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return freed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) static unsigned long super_cache_count(struct shrinker *shrink,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) struct shrink_control *sc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) long total_objects = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) sb = container_of(shrink, struct super_block, s_shrink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * We don't call trylock_super() here as it is a scalability bottleneck,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * so we're exposed to partial setup state. The shrinker rwsem does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * protect filesystem operations backing list_lru_shrink_count() or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * s_op->nr_cached_objects(). Counts can change between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) * super_cache_count and super_cache_scan, so we really don't need locks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) * here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * However, if we are currently mounting the superblock, the underlying
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * filesystem might be in a state of partial construction and hence it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * is dangerous to access it. trylock_super() uses a SB_BORN check to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * avoid this situation, so do the same here. The memory barrier is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * matched with the one in mount_fs() as we don't hold locks here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) if (!(sb->s_flags & SB_BORN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) if (sb->s_op && sb->s_op->nr_cached_objects)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) total_objects = sb->s_op->nr_cached_objects(sb, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) total_objects += list_lru_shrink_count(&sb->s_dentry_lru, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) total_objects += list_lru_shrink_count(&sb->s_inode_lru, sc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) if (!total_objects)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) return SHRINK_EMPTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) total_objects = vfs_pressure_ratio(total_objects);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) return total_objects;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) static void destroy_super_work(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) struct super_block *s = container_of(work, struct super_block,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) destroy_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) for (i = 0; i < SB_FREEZE_LEVELS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) percpu_free_rwsem(&s->s_writers.rw_sem[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) kfree(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) static void destroy_super_rcu(struct rcu_head *head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) struct super_block *s = container_of(head, struct super_block, rcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) INIT_WORK(&s->destroy_work, destroy_super_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) schedule_work(&s->destroy_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) /* Free a superblock that has never been seen by anyone */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) static void destroy_unused_super(struct super_block *s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) if (!s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) up_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) list_lru_destroy(&s->s_dentry_lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) list_lru_destroy(&s->s_inode_lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) security_sb_free(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) put_user_ns(s->s_user_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) kfree(s->s_subtype);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) free_prealloced_shrinker(&s->s_shrink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /* no delays needed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) destroy_super_work(&s->destroy_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) * alloc_super - create new superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * @type: filesystem type superblock should belong to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) * @flags: the mount flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * @user_ns: User namespace for the super_block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * Allocates and initializes a new &struct super_block. alloc_super()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * returns a pointer new superblock or %NULL if allocation had failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) static struct super_block *alloc_super(struct file_system_type *type, int flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) struct user_namespace *user_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) static const struct super_operations default_op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (!s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) INIT_LIST_HEAD(&s->s_mounts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) s->s_user_ns = get_user_ns(user_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) init_rwsem(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) lockdep_set_class(&s->s_umount, &type->s_umount_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * sget() can have s_umount recursion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * When it cannot find a suitable sb, it allocates a new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) * one (this one), and tries again to find a suitable old
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * In case that succeeds, it will acquire the s_umount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) * lock of the old one. Since these are clearly distrinct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) * locks, and this object isn't exposed yet, there's no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) * risk of deadlocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) * Annotate this by putting this lock in a different
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) * subclass.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) if (security_sb_alloc(s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) for (i = 0; i < SB_FREEZE_LEVELS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) if (__percpu_init_rwsem(&s->s_writers.rw_sem[i],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) sb_writers_name[i],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) &type->s_writers_key[i]))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) init_waitqueue_head(&s->s_writers.wait_unfrozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) s->s_bdi = &noop_backing_dev_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) s->s_flags = flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) if (s->s_user_ns != &init_user_ns)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) s->s_iflags |= SB_I_NODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) INIT_HLIST_NODE(&s->s_instances);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) INIT_HLIST_BL_HEAD(&s->s_roots);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) mutex_init(&s->s_sync_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) INIT_LIST_HEAD(&s->s_inodes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) spin_lock_init(&s->s_inode_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) INIT_LIST_HEAD(&s->s_inodes_wb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) spin_lock_init(&s->s_inode_wblist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) s->s_count = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) atomic_set(&s->s_active, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) mutex_init(&s->s_vfs_rename_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) init_rwsem(&s->s_dquot.dqio_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) s->s_maxbytes = MAX_NON_LFS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) s->s_op = &default_op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) s->s_time_gran = 1000000000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) s->s_time_min = TIME64_MIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) s->s_time_max = TIME64_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) s->cleancache_poolid = CLEANCACHE_NO_POOL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) s->s_shrink.seeks = DEFAULT_SEEKS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) s->s_shrink.scan_objects = super_cache_scan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) s->s_shrink.count_objects = super_cache_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) s->s_shrink.batch = 1024;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) s->s_shrink.flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) if (prealloc_shrinker(&s->s_shrink))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) if (list_lru_init_memcg(&s->s_dentry_lru, &s->s_shrink))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) if (list_lru_init_memcg(&s->s_inode_lru, &s->s_shrink))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) return s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) /* Superblock refcounting */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * Drop a superblock's refcount. The caller must hold sb_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) static void __put_super(struct super_block *s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) if (!--s->s_count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) list_del_init(&s->s_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) WARN_ON(s->s_dentry_lru.node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) WARN_ON(s->s_inode_lru.node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) WARN_ON(!list_empty(&s->s_mounts));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) security_sb_free(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) fscrypt_sb_free(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) put_user_ns(s->s_user_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) kfree(s->s_subtype);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) call_rcu(&s->rcu, destroy_super_rcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * put_super - drop a temporary reference to superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) * @sb: superblock in question
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * Drops a temporary reference, frees superblock if there's no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) * references left.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) static void put_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) __put_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) * deactivate_locked_super - drop an active reference to superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) * @s: superblock to deactivate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * Drops an active reference to superblock, converting it into a temporary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * one if there is no other active references left. In that case we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * tell fs driver to shut it down and drop the temporary reference we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * had just acquired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * Caller holds exclusive lock on superblock; that lock is released.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) void deactivate_locked_super(struct super_block *s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) struct file_system_type *fs = s->s_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) if (atomic_dec_and_test(&s->s_active)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) cleancache_invalidate_fs(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) unregister_shrinker(&s->s_shrink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) fs->kill_sb(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) * Since list_lru_destroy() may sleep, we cannot call it from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) * put_super(), where we hold the sb_lock. Therefore we destroy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) * the lru lists right now.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) list_lru_destroy(&s->s_dentry_lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) list_lru_destroy(&s->s_inode_lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) put_filesystem(fs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) put_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) up_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) EXPORT_SYMBOL(deactivate_locked_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) * deactivate_super - drop an active reference to superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * @s: superblock to deactivate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * Variant of deactivate_locked_super(), except that superblock is *not*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) * locked by caller. If we are going to drop the final active reference,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * lock will be acquired prior to that.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) void deactivate_super(struct super_block *s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (!atomic_add_unless(&s->s_active, -1, 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) down_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) EXPORT_SYMBOL(deactivate_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) * grab_super - acquire an active reference
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * @s: reference we are trying to make active
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * Tries to acquire an active reference. grab_super() is used when we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) * had just found a superblock in super_blocks or fs_type->fs_supers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) * and want to turn it into a full-blown active reference. grab_super()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * is called with sb_lock held and drops it. Returns 1 in case of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) * success, 0 if we had failed (superblock contents was already dead or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * dying when grab_super() had been called). Note that this is only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * called for superblocks not in rundown mode (== ones still on ->fs_supers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) * of their type), so increment of ->s_count is OK here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) static int grab_super(struct super_block *s) __releases(sb_lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) s->s_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) down_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) if ((s->s_flags & SB_BORN) && atomic_inc_not_zero(&s->s_active)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) put_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) up_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) put_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) * trylock_super - try to grab ->s_umount shared
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * @sb: reference we are trying to grab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) * Try to prevent fs shutdown. This is used in places where we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) * cannot take an active reference but we need to ensure that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * filesystem is not shut down while we are working on it. It returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * false if we cannot acquire s_umount or if we lose the race and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * filesystem already got into shutdown, and returns true with the s_umount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * lock held in read mode in case of success. On successful return,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * the caller must drop the s_umount lock when done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) * Note that unlike get_super() et.al. this one does *not* bump ->s_count.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * The reason why it's safe is that we are OK with doing trylock instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) * of down_read(). There's a couple of places that are OK with that, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) * it's very much not a general-purpose interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) bool trylock_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) if (down_read_trylock(&sb->s_umount)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) if (!hlist_unhashed(&sb->s_instances) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) sb->s_root && (sb->s_flags & SB_BORN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) * generic_shutdown_super - common helper for ->kill_sb()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) * @sb: superblock to kill
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) * generic_shutdown_super() does all fs-independent work on superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) * shutdown. Typical ->kill_sb() should pick all fs-specific objects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) * that need destruction out of superblock, call generic_shutdown_super()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) * and release aforementioned objects. Note: dentries and inodes _are_
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) * taken care of and do not need specific handling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) * Upon calling this function, the filesystem may no longer alter or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * rearrange the set of dentries belonging to this super_block, nor may it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) * change the attachments of dentries to inodes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) void generic_shutdown_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) const struct super_operations *sop = sb->s_op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) if (sb->s_root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) shrink_dcache_for_umount(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) sync_filesystem(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) sb->s_flags &= ~SB_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) cgroup_writeback_umount();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) /* evict all inodes with zero refcount */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) evict_inodes(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) /* only nonzero refcount inodes can have marks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) fsnotify_sb_delete(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) if (sb->s_dio_done_wq) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) destroy_workqueue(sb->s_dio_done_wq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) sb->s_dio_done_wq = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) if (sop->put_super)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) sop->put_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) if (!list_empty(&sb->s_inodes)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) printk("VFS: Busy inodes after unmount of %s. "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) "Self-destruct in 5 seconds. Have a nice day...\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) sb->s_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) /* should be initialized for __put_super_and_need_restart() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) hlist_del_init(&sb->s_instances);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) if (sb->s_bdi != &noop_backing_dev_info) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) bdi_put(sb->s_bdi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) sb->s_bdi = &noop_backing_dev_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) EXPORT_SYMBOL(generic_shutdown_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) bool mount_capable(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) if (!(fc->fs_type->fs_flags & FS_USERNS_MOUNT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) return capable(CAP_SYS_ADMIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) return ns_capable(fc->user_ns, CAP_SYS_ADMIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) * sget_fc - Find or create a superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) * @fc: Filesystem context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) * @test: Comparison callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) * @set: Setup callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) * Find or create a superblock using the parameters stored in the filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) * context and the two callback functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) * If an extant superblock is matched, then that will be returned with an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) * elevated reference count that the caller must transfer or discard.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) * If no match is made, a new superblock will be allocated and basic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * initialisation will be performed (s_type, s_fs_info and s_id will be set and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) * the set() callback will be invoked), the superblock will be published and it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) * will be returned in a partially constructed state with SB_BORN and SB_ACTIVE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * as yet unset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) struct super_block *sget_fc(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) int (*test)(struct super_block *, struct fs_context *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) int (*set)(struct super_block *, struct fs_context *))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) struct super_block *s = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) struct super_block *old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) struct user_namespace *user_ns = fc->global ? &init_user_ns : fc->user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) retry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (test) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) hlist_for_each_entry(old, &fc->fs_type->fs_supers, s_instances) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) if (test(old, fc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) goto share_extant_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) if (!s) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) s = alloc_super(fc->fs_type, fc->sb_flags, user_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) if (!s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) s->s_fs_info = fc->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) err = set(s, fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) s->s_fs_info = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) fc->s_fs_info = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) s->s_type = fc->fs_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) s->s_iflags |= fc->s_iflags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) strlcpy(s->s_id, s->s_type->name, sizeof(s->s_id));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) list_add_tail(&s->s_list, &super_blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) hlist_add_head(&s->s_instances, &s->s_type->fs_supers);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) get_filesystem(s->s_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) register_shrinker_prepared(&s->s_shrink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) return s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) share_extant_sb:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) if (user_ns != old->s_user_ns) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) return ERR_PTR(-EBUSY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) if (!grab_super(old))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) return old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) EXPORT_SYMBOL(sget_fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) * sget - find or create a superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) * @type: filesystem type superblock should belong to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) * @test: comparison callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) * @set: setup callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) * @flags: mount flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) * @data: argument to each of them
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) struct super_block *sget(struct file_system_type *type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) int (*test)(struct super_block *,void *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) int (*set)(struct super_block *,void *),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) int flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) struct user_namespace *user_ns = current_user_ns();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) struct super_block *s = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) struct super_block *old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) /* We don't yet pass the user namespace of the parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) * mount through to here so always use &init_user_ns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) * until that changes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) if (flags & SB_SUBMOUNT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) user_ns = &init_user_ns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) retry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) if (test) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) hlist_for_each_entry(old, &type->fs_supers, s_instances) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) if (!test(old, data))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) if (user_ns != old->s_user_ns) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) return ERR_PTR(-EBUSY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) if (!grab_super(old))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) return old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (!s) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) s = alloc_super(type, (flags & ~SB_SUBMOUNT), user_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) if (!s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) err = set(s, data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) destroy_unused_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) s->s_type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) strlcpy(s->s_id, type->name, sizeof(s->s_id));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) list_add_tail(&s->s_list, &super_blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) hlist_add_head(&s->s_instances, &type->fs_supers);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) get_filesystem(type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) register_shrinker_prepared(&s->s_shrink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) return s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) EXPORT_SYMBOL(sget);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) void drop_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) put_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) EXPORT_SYMBOL(drop_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) void drop_super_exclusive(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) put_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) EXPORT_SYMBOL(drop_super_exclusive);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) static void __iterate_supers(void (*f)(struct super_block *))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) struct super_block *sb, *p = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) list_for_each_entry(sb, &super_blocks, s_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) if (hlist_unhashed(&sb->s_instances))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) sb->s_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) f(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) __put_super(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) p = sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) __put_super(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) * iterate_supers - call function for all active superblocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) * @f: function to call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) * @arg: argument to pass to it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) * Scans the superblock list and calls given function, passing it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) * locked superblock and given argument.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) struct super_block *sb, *p = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) list_for_each_entry(sb, &super_blocks, s_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) if (hlist_unhashed(&sb->s_instances))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) sb->s_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) down_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) if (sb->s_root && (sb->s_flags & SB_BORN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) f(sb, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) __put_super(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) p = sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) __put_super(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) * iterate_supers_type - call function for superblocks of given type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) * @type: fs type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) * @f: function to call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) * @arg: argument to pass to it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) * Scans the superblock list and calls given function, passing it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) * locked superblock and given argument.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) void iterate_supers_type(struct file_system_type *type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) void (*f)(struct super_block *, void *), void *arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) struct super_block *sb, *p = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) hlist_for_each_entry(sb, &type->fs_supers, s_instances) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) sb->s_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) down_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) if (sb->s_root && (sb->s_flags & SB_BORN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) f(sb, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) __put_super(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) p = sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) __put_super(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) EXPORT_SYMBOL(iterate_supers_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) static struct super_block *__get_super(struct block_device *bdev, bool excl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) if (!bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) rescan:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) list_for_each_entry(sb, &super_blocks, s_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) if (hlist_unhashed(&sb->s_instances))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) if (sb->s_bdev == bdev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) sb->s_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) if (!excl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) down_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) /* still alive? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) if (sb->s_root && (sb->s_flags & SB_BORN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) return sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) if (!excl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) /* nope, got unmounted */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) __put_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) goto rescan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) * get_super - get the superblock of a device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) * @bdev: device to get the superblock for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) * Scans the superblock list and finds the superblock of the file system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) * mounted on the device given. %NULL is returned if no match is found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) struct super_block *get_super(struct block_device *bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) return __get_super(bdev, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) EXPORT_SYMBOL(get_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) static struct super_block *__get_super_thawed(struct block_device *bdev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) bool excl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) struct super_block *s = __get_super(bdev, excl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) if (!s || s->s_writers.frozen == SB_UNFROZEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) return s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) if (!excl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) up_read(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) up_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) wait_event(s->s_writers.wait_unfrozen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) s->s_writers.frozen == SB_UNFROZEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) put_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) * get_super_thawed - get thawed superblock of a device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) * @bdev: device to get the superblock for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) * Scans the superblock list and finds the superblock of the file system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) * mounted on the device. The superblock is returned once it is thawed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) * (or immediately if it was not frozen). %NULL is returned if no match
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) * is found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) struct super_block *get_super_thawed(struct block_device *bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) return __get_super_thawed(bdev, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) EXPORT_SYMBOL(get_super_thawed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) * get_super_exclusive_thawed - get thawed superblock of a device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) * @bdev: device to get the superblock for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) * Scans the superblock list and finds the superblock of the file system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) * mounted on the device. The superblock is returned once it is thawed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) * (or immediately if it was not frozen) and s_umount semaphore is held
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) * in exclusive mode. %NULL is returned if no match is found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) struct super_block *get_super_exclusive_thawed(struct block_device *bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) return __get_super_thawed(bdev, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) EXPORT_SYMBOL(get_super_exclusive_thawed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) * get_active_super - get an active reference to the superblock of a device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) * @bdev: device to get the superblock for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) * Scans the superblock list and finds the superblock of the file system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) * mounted on the device given. Returns the superblock with an active
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) * reference or %NULL if none was found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) struct super_block *get_active_super(struct block_device *bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) if (!bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) restart:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) list_for_each_entry(sb, &super_blocks, s_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) if (hlist_unhashed(&sb->s_instances))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) if (sb->s_bdev == bdev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) if (!grab_super(sb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) goto restart;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) return sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) struct super_block *user_get_super(dev_t dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) rescan:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) list_for_each_entry(sb, &super_blocks, s_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) if (hlist_unhashed(&sb->s_instances))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) if (sb->s_dev == dev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) sb->s_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) down_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) /* still alive? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) if (sb->s_root && (sb->s_flags & SB_BORN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) return sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) up_read(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) /* nope, got unmounted */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) spin_lock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) __put_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) goto rescan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) spin_unlock(&sb_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) * reconfigure_super - asks filesystem to change superblock parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) * @fc: The superblock and configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) * Alters the configuration parameters of a live superblock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) int reconfigure_super(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) struct super_block *sb = fc->root->d_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) bool remount_ro = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) bool force = fc->sb_flags & SB_FORCE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) if (fc->sb_flags_mask & ~MS_RMT_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) if (sb->s_writers.frozen != SB_UNFROZEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) retval = security_sb_remount(sb, fc->security);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) if (fc->sb_flags_mask & SB_RDONLY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) #ifdef CONFIG_BLOCK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) if (!(fc->sb_flags & SB_RDONLY) && bdev_read_only(sb->s_bdev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) return -EACCES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) remount_ro = (fc->sb_flags & SB_RDONLY) && !sb_rdonly(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) if (remount_ro) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) if (!hlist_empty(&sb->s_pins)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) group_pin_kill(&sb->s_pins);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) if (!sb->s_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) if (sb->s_writers.frozen != SB_UNFROZEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) remount_ro = !sb_rdonly(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) shrink_dcache_sb(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) /* If we are reconfiguring to RDONLY and current sb is read/write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) * make sure there are no files open for writing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) if (remount_ro) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) if (force) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) sb->s_readonly_remount = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) retval = sb_prepare_remount_readonly(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) if (fc->ops->reconfigure) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) retval = fc->ops->reconfigure(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) if (retval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) if (!force)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) goto cancel_readonly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) /* If forced remount, go ahead despite any errors */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) WARN(1, "forced remount of a %s fs returned %i\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) sb->s_type->name, retval);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) WRITE_ONCE(sb->s_flags, ((sb->s_flags & ~fc->sb_flags_mask) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) (fc->sb_flags & fc->sb_flags_mask)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) /* Needs to be ordered wrt mnt_is_readonly() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) sb->s_readonly_remount = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) * Some filesystems modify their metadata via some other path than the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) * bdev buffer cache (eg. use a private mapping, or directories in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) * pagecache, etc). Also file data modifications go via their own
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) * mappings. So If we try to mount readonly then copy the filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) * from bdev, we could get stale data, so invalidate it to give a best
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) * effort at coherency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) if (remount_ro && sb->s_bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) invalidate_bdev(sb->s_bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) cancel_readonly:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) sb->s_readonly_remount = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) static void do_emergency_remount_callback(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) if (sb->s_root && sb->s_bdev && (sb->s_flags & SB_BORN) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) !sb_rdonly(sb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) struct fs_context *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) fc = fs_context_for_reconfigure(sb->s_root,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) SB_RDONLY | SB_FORCE, SB_RDONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) if (!IS_ERR(fc)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) if (parse_monolithic_mount_data(fc, NULL) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) (void)reconfigure_super(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) put_fs_context(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) static void do_emergency_remount(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) __iterate_supers(do_emergency_remount_callback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) kfree(work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) printk("Emergency Remount complete\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) void emergency_remount(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) struct work_struct *work;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) work = kmalloc(sizeof(*work), GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) if (work) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) INIT_WORK(work, do_emergency_remount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) schedule_work(work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) static void do_thaw_all_callback(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) if (sb->s_root && sb->s_flags & SB_BORN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) emergency_thaw_bdev(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) thaw_super_locked(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) static void do_thaw_all(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) __iterate_supers(do_thaw_all_callback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) kfree(work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) printk(KERN_WARNING "Emergency Thaw complete\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) * emergency_thaw_all -- forcibly thaw every frozen filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) * Used for emergency unfreeze of all filesystems via SysRq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) void emergency_thaw_all(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) struct work_struct *work;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) work = kmalloc(sizeof(*work), GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) if (work) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) INIT_WORK(work, do_thaw_all);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) schedule_work(work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) static DEFINE_IDA(unnamed_dev_ida);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) * get_anon_bdev - Allocate a block device for filesystems which don't have one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) * @p: Pointer to a dev_t.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) * Filesystems which don't use real block devices can call this function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) * to allocate a virtual block device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) * Context: Any context. Frequently called while holding sb_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) * Return: 0 on success, -EMFILE if there are no anonymous bdevs left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) * or -ENOMEM if memory allocation failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) int get_anon_bdev(dev_t *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) int dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) * Many userspace utilities consider an FSID of 0 invalid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) * Always return at least 1 from get_anon_bdev.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) dev = ida_alloc_range(&unnamed_dev_ida, 1, (1 << MINORBITS) - 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) if (dev == -ENOSPC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) dev = -EMFILE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) if (dev < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) return dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) *p = MKDEV(0, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) EXPORT_SYMBOL(get_anon_bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) void free_anon_bdev(dev_t dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) ida_free(&unnamed_dev_ida, MINOR(dev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) EXPORT_SYMBOL(free_anon_bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) int set_anon_super(struct super_block *s, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) return get_anon_bdev(&s->s_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) EXPORT_SYMBOL(set_anon_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) void kill_anon_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) dev_t dev = sb->s_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) generic_shutdown_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) free_anon_bdev(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) EXPORT_SYMBOL(kill_anon_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) void kill_litter_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) if (sb->s_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) d_genocide(sb->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) kill_anon_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) EXPORT_SYMBOL(kill_litter_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) int set_anon_super_fc(struct super_block *sb, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) return set_anon_super(sb, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) EXPORT_SYMBOL(set_anon_super_fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) static int test_keyed_super(struct super_block *sb, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) return sb->s_fs_info == fc->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) static int test_single_super(struct super_block *s, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) * vfs_get_super - Get a superblock with a search key set in s_fs_info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) * @fc: The filesystem context holding the parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) * @keying: How to distinguish superblocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) * @fill_super: Helper to initialise a new superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) * Search for a superblock and create a new one if not found. The search
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) * criterion is controlled by @keying. If the search fails, a new superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) * is created and @fill_super() is called to initialise it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) * @keying can take one of a number of values:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) * (1) vfs_get_single_super - Only one superblock of this type may exist on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) * system. This is typically used for special system filesystems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) * (2) vfs_get_keyed_super - Multiple superblocks may exist, but they must have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) * distinct keys (where the key is in s_fs_info). Searching for the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) * key again will turn up the superblock for that key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) * (3) vfs_get_independent_super - Multiple superblocks may exist and are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) * unkeyed. Each call will get a new superblock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) * A permissions check is made by sget_fc() unless we're getting a superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) * for a kernel-internal mount or a submount.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) int vfs_get_super(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) enum vfs_get_super_keying keying,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) int (*fill_super)(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) struct fs_context *fc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) int (*test)(struct super_block *, struct fs_context *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) switch (keying) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) case vfs_get_single_super:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) case vfs_get_single_reconf_super:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) test = test_single_super;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) case vfs_get_keyed_super:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) test = test_keyed_super;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) case vfs_get_independent_super:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) test = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) sb = sget_fc(fc, test, set_anon_super_fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) if (IS_ERR(sb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) return PTR_ERR(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) if (!sb->s_root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) err = fill_super(sb, fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) sb->s_flags |= SB_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) fc->root = dget(sb->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) fc->root = dget(sb->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) if (keying == vfs_get_single_reconf_super) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) err = reconfigure_super(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) dput(fc->root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) fc->root = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) deactivate_locked_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) EXPORT_SYMBOL(vfs_get_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) int get_tree_nodev(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) int (*fill_super)(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) struct fs_context *fc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) return vfs_get_super(fc, vfs_get_independent_super, fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) EXPORT_SYMBOL(get_tree_nodev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) int get_tree_single(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) int (*fill_super)(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) struct fs_context *fc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) return vfs_get_super(fc, vfs_get_single_super, fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) EXPORT_SYMBOL(get_tree_single);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) int get_tree_single_reconf(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) int (*fill_super)(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) struct fs_context *fc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) return vfs_get_super(fc, vfs_get_single_reconf_super, fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) EXPORT_SYMBOL(get_tree_single_reconf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) int get_tree_keyed(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) int (*fill_super)(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) struct fs_context *fc),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) void *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) fc->s_fs_info = key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) return vfs_get_super(fc, vfs_get_keyed_super, fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) EXPORT_SYMBOL(get_tree_keyed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) #ifdef CONFIG_BLOCK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) static int set_bdev_super(struct super_block *s, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) s->s_bdev = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) s->s_dev = s->s_bdev->bd_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) s->s_bdi = bdi_get(s->s_bdev->bd_bdi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) if (blk_queue_stable_writes(s->s_bdev->bd_disk->queue))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) s->s_iflags |= SB_I_STABLE_WRITES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) static int set_bdev_super_fc(struct super_block *s, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) return set_bdev_super(s, fc->sget_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) static int test_bdev_super_fc(struct super_block *s, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) return s->s_bdev == fc->sget_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) * get_tree_bdev - Get a superblock based on a single block device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) * @fc: The filesystem context holding the parameters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) * @fill_super: Helper to initialise a new superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) int get_tree_bdev(struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) int (*fill_super)(struct super_block *,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) struct fs_context *))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) struct block_device *bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) struct super_block *s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) fmode_t mode = FMODE_READ | FMODE_EXCL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) int error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) if (!(fc->sb_flags & SB_RDONLY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) mode |= FMODE_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) if (!fc->source)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) return invalf(fc, "No source specified");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) bdev = blkdev_get_by_path(fc->source, mode, fc->fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) if (IS_ERR(bdev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) errorf(fc, "%s: Can't open blockdev", fc->source);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) return PTR_ERR(bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) /* Once the superblock is inserted into the list by sget_fc(), s_umount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) * will protect the lockfs code from trying to start a snapshot while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) * we are mounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) mutex_lock(&bdev->bd_fsfreeze_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) if (bdev->bd_fsfreeze_count > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) mutex_unlock(&bdev->bd_fsfreeze_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) warnf(fc, "%pg: Can't mount, blockdev is frozen", bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) blkdev_put(bdev, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) fc->sb_flags |= SB_NOSEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) fc->sget_key = bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) s = sget_fc(fc, test_bdev_super_fc, set_bdev_super_fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) mutex_unlock(&bdev->bd_fsfreeze_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) if (IS_ERR(s)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) blkdev_put(bdev, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) return PTR_ERR(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) if (s->s_root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) /* Don't summarily change the RO/RW state. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) if ((fc->sb_flags ^ s->s_flags) & SB_RDONLY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) warnf(fc, "%pg: Can't mount, would change RO state", bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) blkdev_put(bdev, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) * s_umount nests inside bd_mutex during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) * __invalidate_device(). blkdev_put() acquires
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) * bd_mutex and can't be called under s_umount. Drop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) * s_umount temporarily. This is safe as we're
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) * holding an active reference.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) up_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) blkdev_put(bdev, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) down_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) s->s_mode = mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) sb_set_blocksize(s, block_size(bdev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) error = fill_super(s, fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) if (error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) s->s_flags |= SB_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) bdev->bd_super = s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) BUG_ON(fc->root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) fc->root = dget(s->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) EXPORT_SYMBOL(get_tree_bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) static int test_bdev_super(struct super_block *s, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) return (void *)s->s_bdev == data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) struct dentry *mount_bdev(struct file_system_type *fs_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) int flags, const char *dev_name, void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) int (*fill_super)(struct super_block *, void *, int))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) struct block_device *bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) struct super_block *s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) fmode_t mode = FMODE_READ | FMODE_EXCL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) int error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) if (!(flags & SB_RDONLY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) mode |= FMODE_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) bdev = blkdev_get_by_path(dev_name, mode, fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) if (IS_ERR(bdev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) return ERR_CAST(bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) * once the super is inserted into the list by sget, s_umount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) * will protect the lockfs code from trying to start a snapshot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) * while we are mounting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) mutex_lock(&bdev->bd_fsfreeze_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) if (bdev->bd_fsfreeze_count > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) mutex_unlock(&bdev->bd_fsfreeze_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) error = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) goto error_bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) s = sget(fs_type, test_bdev_super, set_bdev_super, flags | SB_NOSEC,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) mutex_unlock(&bdev->bd_fsfreeze_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) if (IS_ERR(s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) goto error_s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) if (s->s_root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) if ((flags ^ s->s_flags) & SB_RDONLY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) error = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) goto error_bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) * s_umount nests inside bd_mutex during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) * __invalidate_device(). blkdev_put() acquires
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) * bd_mutex and can't be called under s_umount. Drop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) * s_umount temporarily. This is safe as we're
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) * holding an active reference.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) up_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) blkdev_put(bdev, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) down_write(&s->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) s->s_mode = mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) sb_set_blocksize(s, block_size(bdev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) error = fill_super(s, data, flags & SB_SILENT ? 1 : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) if (error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) s->s_flags |= SB_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) bdev->bd_super = s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) return dget(s->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) error_s:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) error = PTR_ERR(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) error_bdev:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) blkdev_put(bdev, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) return ERR_PTR(error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) EXPORT_SYMBOL_NS(mount_bdev, ANDROID_GKI_VFS_EXPORT_ONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) void kill_block_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) struct block_device *bdev = sb->s_bdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) fmode_t mode = sb->s_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) bdev->bd_super = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) generic_shutdown_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) sync_blockdev(bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) WARN_ON_ONCE(!(mode & FMODE_EXCL));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) blkdev_put(bdev, mode | FMODE_EXCL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) EXPORT_SYMBOL_NS(kill_block_super, ANDROID_GKI_VFS_EXPORT_ONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) struct dentry *mount_nodev(struct file_system_type *fs_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) int flags, void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) int (*fill_super)(struct super_block *, void *, int))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) struct super_block *s = sget(fs_type, NULL, set_anon_super, flags, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) if (IS_ERR(s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) return ERR_CAST(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) error = fill_super(s, data, flags & SB_SILENT ? 1 : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) if (error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) return ERR_PTR(error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) s->s_flags |= SB_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) return dget(s->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) EXPORT_SYMBOL(mount_nodev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) int reconfigure_single(struct super_block *s,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) int flags, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) struct fs_context *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) /* The caller really need to be passing fc down into mount_single(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) * then a chunk of this can be removed. [Bollocks -- AV]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) * Better yet, reconfiguration shouldn't happen, but rather the second
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) * mount should be rejected if the parameters are not compatible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) fc = fs_context_for_reconfigure(s->s_root, flags, MS_RMT_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) if (IS_ERR(fc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) return PTR_ERR(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) ret = parse_monolithic_mount_data(fc, data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) ret = reconfigure_super(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) put_fs_context(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) static int compare_single(struct super_block *s, void *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) struct dentry *mount_single(struct file_system_type *fs_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) int flags, void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) int (*fill_super)(struct super_block *, void *, int))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) struct super_block *s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) s = sget(fs_type, compare_single, set_anon_super, flags, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) if (IS_ERR(s))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) return ERR_CAST(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) if (!s->s_root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) error = fill_super(s, data, flags & SB_SILENT ? 1 : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) if (!error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) s->s_flags |= SB_ACTIVE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) error = reconfigure_single(s, flags, data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) if (unlikely(error)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) deactivate_locked_super(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) return ERR_PTR(error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) return dget(s->s_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) EXPORT_SYMBOL(mount_single);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) * vfs_get_tree - Get the mountable root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) * @fc: The superblock configuration context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) * The filesystem is invoked to get or create a superblock which can then later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) * be used for mounting. The filesystem places a pointer to the root to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) * used for mounting in @fc->root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) int vfs_get_tree(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) if (fc->root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) /* Get the mountable root in fc->root, with a ref on the root and a ref
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) * on the superblock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) error = fc->ops->get_tree(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) if (error < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) if (!fc->root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) pr_err("Filesystem %s get_tree() didn't set fc->root\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) fc->fs_type->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) /* We don't know what the locking state of the superblock is -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) * if there is a superblock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) sb = fc->root->d_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) WARN_ON(!sb->s_bdi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) * Write barrier is for super_cache_count(). We place it before setting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) * SB_BORN as the data dependency between the two functions is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) * superblock structure contents that we just set up, not the SB_BORN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) * flag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) sb->s_flags |= SB_BORN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) if (unlikely(error)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) fc_drop_locked(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) * but s_maxbytes was an unsigned long long for many releases. Throw
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) * this warning for a little while to try and catch filesystems that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) * violate this rule.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) WARN((sb->s_maxbytes < 0), "%s set sb->s_maxbytes to "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) "negative value (%lld)\n", fc->fs_type->name, sb->s_maxbytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) EXPORT_SYMBOL(vfs_get_tree);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) * Setup private BDI for given superblock. It gets automatically cleaned up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) * in generic_shutdown_super().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) int super_setup_bdi_name(struct super_block *sb, char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) struct backing_dev_info *bdi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) va_list args;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) bdi = bdi_alloc(NUMA_NO_NODE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) if (!bdi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) va_start(args, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) err = bdi_register_va(bdi, fmt, args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) va_end(args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) bdi_put(bdi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) WARN_ON(sb->s_bdi != &noop_backing_dev_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) sb->s_bdi = bdi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) EXPORT_SYMBOL(super_setup_bdi_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) * Setup private BDI for given superblock. I gets automatically cleaned up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) * in generic_shutdown_super().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) int super_setup_bdi(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) return super_setup_bdi_name(sb, "%.28s-%ld", sb->s_type->name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) atomic_long_inc_return(&bdi_seq));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) EXPORT_SYMBOL(super_setup_bdi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) * sb_wait_write - wait until all writers to given file system finish
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) * @sb: the super for which we wait
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) * @level: type of writers we wait for (normal vs page fault)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) * This function waits until there are no writers of given type to given file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) * system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) static void sb_wait_write(struct super_block *sb, int level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) percpu_down_write(sb->s_writers.rw_sem + level-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) * We are going to return to userspace and forget about these locks, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) * ownership goes to the caller of thaw_super() which does unlock().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) static void lockdep_sb_freeze_release(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) int level;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) for (level = SB_FREEZE_LEVELS - 1; level >= 0; level--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) percpu_rwsem_release(sb->s_writers.rw_sem + level, 0, _THIS_IP_);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) * Tell lockdep we are holding these locks before we call ->unfreeze_fs(sb).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) static void lockdep_sb_freeze_acquire(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) int level;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) for (level = 0; level < SB_FREEZE_LEVELS; ++level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) percpu_rwsem_acquire(sb->s_writers.rw_sem + level, 0, _THIS_IP_);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) static void sb_freeze_unlock(struct super_block *sb, int level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) for (level--; level >= 0; level--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) percpu_up_write(sb->s_writers.rw_sem + level);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) * freeze_super - lock the filesystem and force it into a consistent state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) * @sb: the super to lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) * Syncs the super to make sure the filesystem is consistent and calls the fs's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) * freeze_fs. Subsequent calls to this without first thawing the fs will return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) * -EBUSY.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) * During this function, sb->s_writers.frozen goes through these values:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) * SB_UNFROZEN: File system is normal, all writes progress as usual.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) * SB_FREEZE_WRITE: The file system is in the process of being frozen. New
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) * writes should be blocked, though page faults are still allowed. We wait for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) * all writes to complete and then proceed to the next stage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) * SB_FREEZE_PAGEFAULT: Freezing continues. Now also page faults are blocked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) * but internal fs threads can still modify the filesystem (although they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) * should not dirty new pages or inodes), writeback can run etc. After waiting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) * for all running page faults we sync the filesystem which will clean all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) * dirty pages and inodes (no new dirty pages or inodes can be created when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) * sync is running).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) * SB_FREEZE_FS: The file system is frozen. Now all internal sources of fs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) * modification are blocked (e.g. XFS preallocation truncation on inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) * reclaim). This is usually implemented by blocking new transactions for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) * filesystems that have them and need this additional guard. After all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) * internal writers are finished we call ->freeze_fs() to finish filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) * freezing. Then we transition to SB_FREEZE_COMPLETE state. This state is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) * mostly auxiliary for filesystems to verify they do not modify frozen fs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) * sb->s_writers.frozen is protected by sb->s_umount.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) int freeze_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) atomic_inc(&sb->s_active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) if (sb->s_writers.frozen != SB_UNFROZEN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) deactivate_locked_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) if (!(sb->s_flags & SB_BORN)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) return 0; /* sic - it's "nothing to do" */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) if (sb_rdonly(sb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) /* Nothing to do really... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) sb->s_writers.frozen = SB_FREEZE_COMPLETE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) sb->s_writers.frozen = SB_FREEZE_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) /* Release s_umount to preserve sb_start_write -> s_umount ordering */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) sb_wait_write(sb, SB_FREEZE_WRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) /* Now we go and block page faults... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) sb->s_writers.frozen = SB_FREEZE_PAGEFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) sb_wait_write(sb, SB_FREEZE_PAGEFAULT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) /* All writers are done so after syncing there won't be dirty data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) ret = sync_filesystem(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) sb->s_writers.frozen = SB_UNFROZEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) sb_freeze_unlock(sb, SB_FREEZE_PAGEFAULT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) wake_up(&sb->s_writers.wait_unfrozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) deactivate_locked_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) /* Now wait for internal filesystem counter */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) sb->s_writers.frozen = SB_FREEZE_FS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) sb_wait_write(sb, SB_FREEZE_FS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) if (sb->s_op->freeze_fs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) ret = sb->s_op->freeze_fs(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) printk(KERN_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) "VFS:Filesystem freeze failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) sb->s_writers.frozen = SB_UNFROZEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) sb_freeze_unlock(sb, SB_FREEZE_FS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) wake_up(&sb->s_writers.wait_unfrozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) deactivate_locked_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) * For debugging purposes so that fs can warn if it sees write activity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) * when frozen is set to SB_FREEZE_COMPLETE, and for thaw_super().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) sb->s_writers.frozen = SB_FREEZE_COMPLETE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773) lockdep_sb_freeze_release(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) EXPORT_SYMBOL(freeze_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780) * thaw_super -- unlock filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781) * @sb: the super to thaw
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) * Unlocks the filesystem and marks it writeable again after freeze_super().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) static int thaw_super_locked(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) if (sb_rdonly(sb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) sb->s_writers.frozen = SB_UNFROZEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799) lockdep_sb_freeze_acquire(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) if (sb->s_op->unfreeze_fs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) error = sb->s_op->unfreeze_fs(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) if (error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804) printk(KERN_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) "VFS:Filesystem thaw failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806) lockdep_sb_freeze_release(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) up_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812) sb->s_writers.frozen = SB_UNFROZEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) sb_freeze_unlock(sb, SB_FREEZE_FS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) wake_up(&sb->s_writers.wait_unfrozen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) deactivate_locked_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) int thaw_super(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822) down_write(&sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) return thaw_super_locked(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) EXPORT_SYMBOL(thaw_super);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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