^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) * Squashfs - a compressed read only filesystem for Linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Phillip Lougher <phillip@squashfs.org.uk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * cache.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * Blocks in Squashfs are compressed. To avoid repeatedly decompressing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * recently accessed data Squashfs uses two small metadata and fragment caches.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * This file implements a generic cache implementation used for both caches,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * plus functions layered ontop of the generic cache implementation to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * access the metadata and fragment caches.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * To avoid out of memory and fragmentation issues with vmalloc the cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * uses sequences of kmalloced PAGE_SIZE buffers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * It should be noted that the cache is not used for file datablocks, these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * are decompressed and cached in the page-cache in the normal way. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * cache is only used to temporarily cache fragment and metadata blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * which have been read as as a result of a metadata (i.e. inode or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * directory) or fragment access. Because metadata and fragments are packed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * together into blocks (to gain greater compression) the read of a particular
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * piece of metadata or fragment will retrieve other metadata/fragments which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * have been packed with it, these because of locality-of-reference may be read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * in the near future. Temporarily caching them ensures they are available for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * near future access without requiring an additional read and decompress.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/vfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/vmalloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/wait.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include "squashfs_fs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include "squashfs_fs_sb.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include "squashfs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include "page_actor.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * Look-up block in cache, and increment usage count. If not in cache, read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * and decompress it from disk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) struct squashfs_cache_entry *squashfs_cache_get(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) struct squashfs_cache *cache, u64 block, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) int i, n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct squashfs_cache_entry *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) spin_lock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) for (i = cache->curr_blk, n = 0; n < cache->entries; n++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) if (cache->entry[i].block == block) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) cache->curr_blk = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) i = (i + 1) % cache->entries;
^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) if (n == cache->entries) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * Block not in cache, if all cache entries are used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * go to sleep waiting for one to become available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (cache->unused == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) cache->num_waiters++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) wait_event(cache->wait_queue, cache->unused);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) spin_lock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) cache->num_waiters--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * At least one unused cache entry. A simple
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * round-robin strategy is used to choose the entry to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * be evicted from the cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) i = cache->next_blk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) for (n = 0; n < cache->entries; n++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (cache->entry[i].refcount == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) i = (i + 1) % cache->entries;
^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) cache->next_blk = (i + 1) % cache->entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) entry = &cache->entry[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * Initialise chosen cache entry, and fill it in from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * disk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) cache->unused--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) entry->block = block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) entry->refcount = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) entry->pending = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) entry->num_waiters = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) entry->error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) entry->length = squashfs_read_data(sb, block, length,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) &entry->next_index, entry->actor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) spin_lock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (entry->length < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) entry->error = entry->length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) entry->pending = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * While filling this entry one or more other processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * have looked it up in the cache, and have slept
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * waiting for it to become available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (entry->num_waiters) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) wake_up_all(&entry->wait_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * Block already in cache. Increment refcount so it doesn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * get reused until we're finished with it, if it was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * previously unused there's one less cache entry available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * for reuse.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) entry = &cache->entry[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (entry->refcount == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) cache->unused--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) entry->refcount++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * If the entry is currently being filled in by another process
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * go to sleep waiting for it to become available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) if (entry->pending) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) entry->num_waiters++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) wait_event(entry->wait_queue, !entry->pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) TRACE("Got %s %d, start block %lld, refcount %d, error %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) cache->name, i, entry->block, entry->refcount, entry->error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) if (entry->error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) ERROR("Unable to read %s cache entry [%llx]\n", cache->name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * Release cache entry, once usage count is zero it can be reused.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) void squashfs_cache_put(struct squashfs_cache_entry *entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) struct squashfs_cache *cache = entry->cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) spin_lock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) entry->refcount--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) if (entry->refcount == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) cache->unused++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) * If there's any processes waiting for a block to become
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) * available, wake one up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (cache->num_waiters) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) wake_up(&cache->wait_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) return;
^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) spin_unlock(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * Delete cache reclaiming all kmalloced buffers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) void squashfs_cache_delete(struct squashfs_cache *cache)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) if (cache == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) for (i = 0; i < cache->entries; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) if (cache->entry[i].data) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) for (j = 0; j < cache->pages; j++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) kfree(cache->entry[i].data[j]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) kfree(cache->entry[i].data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) kfree(cache->entry[i].actor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) kfree(cache->entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) kfree(cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * Initialise cache allocating the specified number of entries, each of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * size block_size. To avoid vmalloc fragmentation issues each entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * is allocated as a sequence of kmalloced PAGE_SIZE buffers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) struct squashfs_cache *squashfs_cache_init(char *name, int entries,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) int block_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) struct squashfs_cache *cache = kzalloc(sizeof(*cache), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) if (cache == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) ERROR("Failed to allocate %s cache\n", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) cache->entry = kcalloc(entries, sizeof(*(cache->entry)), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) if (cache->entry == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) ERROR("Failed to allocate %s cache\n", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) cache->curr_blk = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) cache->next_blk = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) cache->unused = entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) cache->entries = entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) cache->block_size = block_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) cache->pages = block_size >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) cache->pages = cache->pages ? cache->pages : 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) cache->name = name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) cache->num_waiters = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) spin_lock_init(&cache->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) init_waitqueue_head(&cache->wait_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) for (i = 0; i < entries; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) struct squashfs_cache_entry *entry = &cache->entry[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) init_waitqueue_head(&cache->entry[i].wait_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) entry->cache = cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) entry->block = SQUASHFS_INVALID_BLK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) entry->data = kcalloc(cache->pages, sizeof(void *), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) if (entry->data == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) ERROR("Failed to allocate %s cache entry\n", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) for (j = 0; j < cache->pages; j++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) entry->data[j] = kmalloc(PAGE_SIZE, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (entry->data[j] == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) ERROR("Failed to allocate %s buffer\n", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) entry->actor = squashfs_page_actor_init(entry->data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) cache->pages, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) if (entry->actor == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) ERROR("Failed to allocate %s cache entry\n", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) return cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) cleanup:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) squashfs_cache_delete(cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * Copy up to length bytes from cache entry to buffer starting at offset bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * into the cache entry. If there's not length bytes then copy the number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * bytes available. In all cases return the number of bytes copied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) int squashfs_copy_data(void *buffer, struct squashfs_cache_entry *entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) int offset, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) int remaining = length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) if (length == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) else if (buffer == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) return min(length, entry->length - offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) while (offset < entry->length) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) void *buff = entry->data[offset / PAGE_SIZE]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) + (offset % PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) int bytes = min_t(int, entry->length - offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) PAGE_SIZE - (offset % PAGE_SIZE));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) if (bytes >= remaining) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) memcpy(buffer, buff, remaining);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) remaining = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) memcpy(buffer, buff, bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) buffer += bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) remaining -= bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) offset += bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) return length - remaining;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * Read length bytes from metadata position <block, offset> (block is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * start of the compressed block on disk, and offset is the offset into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * the block once decompressed). Data is packed into consecutive blocks,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * and length bytes may require reading more than one block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) int squashfs_read_metadata(struct super_block *sb, void *buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) u64 *block, int *offset, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) struct squashfs_sb_info *msblk = sb->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) int bytes, res = length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) struct squashfs_cache_entry *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) TRACE("Entered squashfs_read_metadata [%llx:%x]\n", *block, *offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) if (unlikely(length < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) while (length) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) entry = squashfs_cache_get(sb, msblk->block_cache, *block, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) if (entry->error) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) res = entry->error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) } else if (*offset >= entry->length) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) res = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) bytes = squashfs_copy_data(buffer, entry, *offset, length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) if (buffer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) buffer += bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) length -= bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) *offset += bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) if (*offset == entry->length) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) *block = entry->next_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) *offset = 0;
^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) squashfs_cache_put(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) squashfs_cache_put(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * Look-up in the fragmment cache the fragment located at <start_block> in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) * filesystem. If necessary read and decompress it from disk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) struct squashfs_cache_entry *squashfs_get_fragment(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) u64 start_block, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) struct squashfs_sb_info *msblk = sb->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) return squashfs_cache_get(sb, msblk->fragment_cache, start_block,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) * Read and decompress the datablock located at <start_block> in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) * filesystem. The cache is used here to avoid duplicating locking and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) * read/decompress code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) u64 start_block, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) struct squashfs_sb_info *msblk = sb->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) return squashfs_cache_get(sb, msblk->read_page, start_block, length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) * Read a filesystem table (uncompressed sequence of bytes) from disk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) void *squashfs_read_table(struct super_block *sb, u64 block, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) int pages = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) int i, res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) void *table, *buffer, **data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) struct squashfs_page_actor *actor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) table = buffer = kmalloc(length, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) if (table == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) data = kcalloc(pages, sizeof(void *), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) if (data == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) res = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) actor = squashfs_page_actor_init(data, pages, length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) if (actor == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) res = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) goto failed2;
^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) for (i = 0; i < pages; i++, buffer += PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) data[i] = buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) res = squashfs_read_data(sb, block, length |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, actor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) kfree(data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) kfree(actor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) if (res < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) goto failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) failed2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) kfree(data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) failed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) kfree(table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) return ERR_PTR(res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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