^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/dcache.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/gfp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/srcu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/fsnotify_backend.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "fsnotify.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Clear all of the marks on an inode when it is being evicted from core
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) void __fsnotify_inode_delete(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) fsnotify_clear_marks_by_inode(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) fsnotify_clear_marks_by_mount(mnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * @sb: superblock being unmounted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * Called during unmount with no locks held, so needs to be safe against
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static void fsnotify_unmount_inodes(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) struct inode *inode, *iput_inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) spin_lock(&sb->s_inode_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * We cannot __iget() an inode in state I_FREEING,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * I_WILL_FREE, or I_NEW which is fine because by that point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * the inode cannot have any associated watches.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) spin_lock(&inode->i_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) spin_unlock(&inode->i_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) continue;
^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * If i_count is zero, the inode cannot have any watches and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * doing an __iget/iput with SB_ACTIVE clear would actually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * evict all inodes with zero i_count from icache which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * unnecessarily violent and may in fact be illegal to do.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * However, we should have been called /after/ evict_inodes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * removed all zero refcount inodes, in any case. Test to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * be sure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) if (!atomic_read(&inode->i_count)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) spin_unlock(&inode->i_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) __iget(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) spin_unlock(&inode->i_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) spin_unlock(&sb->s_inode_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) if (iput_inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) iput(iput_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /* for each watch, send FS_UNMOUNT and then remove it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) fsnotify_inode(inode, FS_UNMOUNT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) fsnotify_inode_delete(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) iput_inode = inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) cond_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) spin_lock(&sb->s_inode_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) spin_unlock(&sb->s_inode_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (iput_inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) iput(iput_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* Wait for outstanding inode references from connectors */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) wait_var_event(&sb->s_fsnotify_inode_refs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) !atomic_long_read(&sb->s_fsnotify_inode_refs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) void fsnotify_sb_delete(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) fsnotify_unmount_inodes(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) fsnotify_clear_marks_by_sb(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * Given an inode, first check if we care what happens to our children. Inotify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * and dnotify both tell their parents about events. If we care about any event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * on a child we run all of our children and set a dentry flag saying that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * parent cares. Thus when an event happens on a child it can quickly tell if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * if there is a need to find a parent and send the event to the parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) void __fsnotify_update_child_dentry_flags(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) struct dentry *alias;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) int watched;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (!S_ISDIR(inode->i_mode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) /* determine if the children should tell inode about their events */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) watched = fsnotify_inode_watches_children(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) spin_lock(&inode->i_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) /* run all of the dentries associated with this inode. Since this is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * directory, there damn well better only be one item on this list */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) struct dentry *child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /* run all of the children of the original inode and fix their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * d_flags to indicate parental interest (their parent is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * original inode) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) spin_lock(&alias->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) list_for_each_entry(child, &alias->d_subdirs, d_child) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if (!child->d_inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) if (watched)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) spin_unlock(&child->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) spin_unlock(&alias->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) spin_unlock(&inode->i_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) /* Are inode/sb/mount interested in parent and name info with this event? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) static bool fsnotify_event_needs_parent(struct inode *inode, struct mount *mnt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) __u32 mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) __u32 marks_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) /* We only send parent/name to inode/sb/mount for events on non-dir */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) if (mask & FS_ISDIR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) * All events that are possible on child can also may be reported with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * parent/name info to inode/sb/mount. Otherwise, a watching parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * could result in events reported with unexpected name info to sb/mount.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) BUILD_BUG_ON(FS_EVENTS_POSS_ON_CHILD & ~FS_EVENTS_POSS_TO_PARENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) /* Did either inode/sb/mount subscribe for events with parent/name? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) marks_mask |= fsnotify_parent_needed_mask(inode->i_fsnotify_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) marks_mask |= fsnotify_parent_needed_mask(inode->i_sb->s_fsnotify_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if (mnt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) marks_mask |= fsnotify_parent_needed_mask(mnt->mnt_fsnotify_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) /* Did they subscribe for this event with parent/name info? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) return mask & marks_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * Notify this dentry's parent about a child's events with child name info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * if parent is watching or if inode/sb/mount are interested in events with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * parent and name info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * Notify only the child without name info if parent is not watching and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) * inode/sb/mount are not interested in events with parent and name info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) int data_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) const struct path *path = fsnotify_data_path(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) struct mount *mnt = path ? real_mount(path->mnt) : NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) struct inode *inode = d_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) struct dentry *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) bool parent_watched = dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) bool parent_needed, parent_interested;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) __u32 p_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) struct inode *p_inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) struct name_snapshot name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) struct qstr *file_name = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * Do inode/sb/mount care about parent and name info on non-dir?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * Do they care about any event at all?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) if (!inode->i_fsnotify_marks && !inode->i_sb->s_fsnotify_marks &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) (!mnt || !mnt->mnt_fsnotify_marks) && !parent_watched)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) parent_needed = fsnotify_event_needs_parent(inode, mnt, mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) if (!parent_watched && !parent_needed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) goto notify;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) /* Does parent inode care about events on children? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) parent = dget_parent(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) p_inode = parent->d_inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) p_mask = fsnotify_inode_watches_children(p_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) if (unlikely(parent_watched && !p_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) __fsnotify_update_child_dentry_flags(p_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) * Include parent/name in notification either if some notification
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * groups require parent info or the parent is interested in this event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) parent_interested = mask & p_mask & ALL_FSNOTIFY_EVENTS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) if (parent_needed || parent_interested) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) /* When notifying parent, child should be passed as data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) WARN_ON_ONCE(inode != fsnotify_data_inode(data, data_type));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) /* Notify both parent and child with child name info */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) take_dentry_name_snapshot(&name, dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) file_name = &name.name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) if (parent_interested)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) mask |= FS_EVENT_ON_CHILD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) notify:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) ret = fsnotify(mask, data, data_type, p_inode, file_name, inode, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) if (file_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) release_dentry_name_snapshot(&name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) dput(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) EXPORT_SYMBOL_GPL(__fsnotify_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) static int fsnotify_handle_inode_event(struct fsnotify_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) struct fsnotify_mark *inode_mark,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) u32 mask, const void *data, int data_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) struct inode *dir, const struct qstr *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) u32 cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) const struct path *path = fsnotify_data_path(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) struct inode *inode = fsnotify_data_inode(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) const struct fsnotify_ops *ops = group->ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) if (WARN_ON_ONCE(!ops->handle_inode_event))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) if ((inode_mark->mask & FS_EXCL_UNLINK) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) path && d_unlinked(path->dentry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) /* Check interest of this mark in case event was sent with two marks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) if (!(mask & inode_mark->mask & ALL_FSNOTIFY_EVENTS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) return ops->handle_inode_event(inode_mark, mask, inode, dir, name, cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) static int fsnotify_handle_event(struct fsnotify_group *group, __u32 mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) const void *data, int data_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) struct inode *dir, const struct qstr *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) u32 cookie, struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) struct fsnotify_mark *parent_mark = fsnotify_iter_parent_mark(iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) if (WARN_ON_ONCE(fsnotify_iter_sb_mark(iter_info)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) WARN_ON_ONCE(fsnotify_iter_vfsmount_mark(iter_info)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) if (parent_mark) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * parent_mark indicates that the parent inode is watching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * children and interested in this event, which is an event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * possible on child. But is *this mark* watching children and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * interested in this event?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) if (parent_mark->mask & FS_EVENT_ON_CHILD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) ret = fsnotify_handle_inode_event(group, parent_mark, mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) data, data_type, dir, name, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) if (!inode_mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) if (mask & FS_EVENT_ON_CHILD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * Some events can be sent on both parent dir and child marks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * (e.g. FS_ATTRIB). If both parent dir and child are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * watching, report the event once to parent dir with name (if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * interested) and once to child without name (if interested).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * The child watcher is expecting an event without a file name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * and without the FS_EVENT_ON_CHILD flag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) mask &= ~FS_EVENT_ON_CHILD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) dir = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) name = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) return fsnotify_handle_inode_event(group, inode_mark, mask, data, data_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) dir, name, cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) static int send_to_group(__u32 mask, const void *data, int data_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) struct inode *dir, const struct qstr *file_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) u32 cookie, struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) struct fsnotify_group *group = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) __u32 marks_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) __u32 marks_ignored_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) struct fsnotify_mark *mark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) if (WARN_ON(!iter_info->report_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) /* clear ignored on inode modification */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) if (mask & FS_MODIFY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (!fsnotify_iter_should_report_type(iter_info, type))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) mark = iter_info->marks[type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) if (mark &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) !(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) mark->ignored_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) if (!fsnotify_iter_should_report_type(iter_info, type))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) mark = iter_info->marks[type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) /* does the object mark tell us to do something? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) if (mark) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) group = mark->group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) marks_mask |= mark->mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) marks_ignored_mask |= mark->ignored_mask;
^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) pr_debug("%s: group=%p mask=%x marks_mask=%x marks_ignored_mask=%x data=%p data_type=%d dir=%p cookie=%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) __func__, group, mask, marks_mask, marks_ignored_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) data, data_type, dir, cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) if (!(test_mask & marks_mask & ~marks_ignored_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) if (group->ops->handle_event) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) return group->ops->handle_event(group, mask, data, data_type, dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) file_name, cookie, iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) return fsnotify_handle_event(group, mask, data, data_type, dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) file_name, cookie, iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) struct fsnotify_mark_connector *conn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) struct hlist_node *node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) conn = srcu_dereference(*connp, &fsnotify_mark_srcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) if (conn)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) struct hlist_node *node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) if (mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) node = srcu_dereference(mark->obj_list.next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) &fsnotify_mark_srcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) * iter_info is a multi head priority queue of marks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) * Pick a subset of marks from queue heads, all with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) * same group and set the report_mask for selected subset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * Returns the report_mask of the selected subset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) static unsigned int fsnotify_iter_select_report_types(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) struct fsnotify_group *max_prio_group = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) struct fsnotify_mark *mark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /* Choose max prio group among groups of all queue heads */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) mark = iter_info->marks[type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) if (mark &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) fsnotify_compare_groups(max_prio_group, mark->group) > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) max_prio_group = mark->group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) if (!max_prio_group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) /* Set the report mask for marks from same group as max prio group */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) iter_info->report_mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) mark = iter_info->marks[type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) if (mark &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) fsnotify_compare_groups(max_prio_group, mark->group) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) fsnotify_iter_set_report_type(iter_info, type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) return iter_info->report_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) }
^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) * Pop from iter_info multi head queue, the marks that were iterated in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) * current iteration step.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) fsnotify_foreach_obj_type(type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (fsnotify_iter_should_report_type(iter_info, type))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) iter_info->marks[type] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) fsnotify_next_mark(iter_info->marks[type]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) * fsnotify - This is the main call to fsnotify.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * The VFS calls into hook specific functions in linux/fsnotify.h.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * Those functions then in turn call here. Here will call out to all of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * registered fsnotify_group. Those groups can then use the notification event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * in whatever means they feel necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * @mask: event type and flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * @data: object that event happened on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) * @data_type: type of object for fanotify_data_XXX() accessors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * @dir: optional directory associated with event -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) * if @file_name is not NULL, this is the directory that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) * @file_name is relative to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) * @file_name: optional file name associated with event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) * @inode: optional inode associated with event -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) * either @dir or @inode must be non-NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) * if both are non-NULL event may be reported to both.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) * @cookie: inotify rename cookie
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) const struct qstr *file_name, struct inode *inode, u32 cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) const struct path *path = fsnotify_data_path(data, data_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) struct fsnotify_iter_info iter_info = {};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) struct mount *mnt = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) struct inode *parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) __u32 test_mask, marks_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) if (path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) mnt = real_mount(path->mnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) if (!inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) /* Dirent event - report on TYPE_INODE to dir */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) inode = dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) } else if (mask & FS_EVENT_ON_CHILD) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) * Event on child - report on TYPE_PARENT to dir if it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) * watching children and on TYPE_INODE to child.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) parent = dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) * Optimization: srcu_read_lock() has a memory barrier which can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * be expensive. It protects walking the *_fsnotify_marks lists.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) * However, if we do not walk the lists, we do not have to do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * SRCU because we have no references to any objects and do not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) * need SRCU to keep them "alive".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) if (!sb->s_fsnotify_marks &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) (!mnt || !mnt->mnt_fsnotify_marks) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) (!inode || !inode->i_fsnotify_marks) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) (!parent || !parent->i_fsnotify_marks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) marks_mask = sb->s_fsnotify_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) if (mnt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) marks_mask |= mnt->mnt_fsnotify_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) if (inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) marks_mask |= inode->i_fsnotify_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) if (parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) marks_mask |= parent->i_fsnotify_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) * if this is a modify event we may need to clear the ignored masks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) * otherwise return if none of the marks care about this type of event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) test_mask = (mask & ALL_FSNOTIFY_EVENTS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) if (!(mask & FS_MODIFY) && !(test_mask & marks_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) fsnotify_first_mark(&sb->s_fsnotify_marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (mnt) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) fsnotify_first_mark(&mnt->mnt_fsnotify_marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) if (inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) fsnotify_first_mark(&inode->i_fsnotify_marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) if (parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) iter_info.marks[FSNOTIFY_OBJ_TYPE_PARENT] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) fsnotify_first_mark(&parent->i_fsnotify_marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) }
^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) * We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) * ignore masks are properly reflected for mount/sb mark notifications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) * That's why this traversal is so complicated...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) while (fsnotify_iter_select_report_types(&iter_info)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) ret = send_to_group(mask, data, data_type, dir, file_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) cookie, &iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) fsnotify_iter_next(&iter_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) EXPORT_SYMBOL_GPL(fsnotify);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) static __init int fsnotify_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) ret = init_srcu_struct(&fsnotify_mark_srcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) panic("initializing fsnotify_mark_srcu");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) SLAB_PANIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) core_initcall(fsnotify_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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