diff options
Diffstat (limited to 'fs/squashfs/inode.c')
| -rw-r--r-- | fs/squashfs/inode.c | 2157 |
1 files changed, 2157 insertions, 0 deletions
diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c new file mode 100644 index 000000000000..a9b9d8c7dfad --- /dev/null +++ b/fs/squashfs/inode.c @@ -0,0 +1,2157 @@ +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 + * Phillip Lougher <phillip@lougher.demon.co.uk> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2, + * or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * inode.c + */ + +#include <linux/squashfs_fs.h> +#include <linux/module.h> +#include <linux/zlib.h> +#include <linux/fs.h> +#include <linux/squashfs_fs_sb.h> +#include <linux/squashfs_fs_i.h> +#include <linux/buffer_head.h> +#include <linux/vfs.h> +#include <linux/vmalloc.h> +#include <linux/spinlock.h> +#include <linux/smp_lock.h> +#include <linux/exportfs.h> + +#include "squashfs.h" + +static struct dentry *squashfs_fh_to_dentry(struct super_block *s, + struct fid *fid, int fh_len, int fh_type); +static struct dentry *squashfs_fh_to_parent(struct super_block *s, + struct fid *fid, int fh_len, int fh_type); +static struct dentry *squashfs_get_parent(struct dentry *child); +static int squashfs_read_inode(struct inode *i, squashfs_inode_t inode); +static int squashfs_statfs(struct dentry *, struct kstatfs *); +static int squashfs_symlink_readpage(struct file *file, struct page *page); +static long long read_blocklist(struct inode *inode, int index, + int readahead_blks, char *block_list, + unsigned short **block_p, unsigned int *bsize); +static int squashfs_readpage(struct file *file, struct page *page); +static int squashfs_readdir(struct file *, void *, filldir_t); +static struct dentry *squashfs_lookup(struct inode *, struct dentry *, + struct nameidata *); +static int squashfs_remount(struct super_block *s, int *flags, char *data); +static void squashfs_put_super(struct super_block *); +static int squashfs_get_sb(struct file_system_type *,int, const char *, void *, + struct vfsmount *); +static struct inode *squashfs_alloc_inode(struct super_block *sb); +static void squashfs_destroy_inode(struct inode *inode); +static int init_inodecache(void); +static void destroy_inodecache(void); + +static struct file_system_type squashfs_fs_type = { + .owner = THIS_MODULE, + .name = "squashfs", + .get_sb = squashfs_get_sb, + .kill_sb = kill_block_super, + .fs_flags = FS_REQUIRES_DEV +}; + +static const unsigned char squashfs_filetype_table[] = { + DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_FIFO, DT_SOCK +}; + +static struct super_operations squashfs_super_ops = { + .alloc_inode = squashfs_alloc_inode, + .destroy_inode = squashfs_destroy_inode, + .statfs = squashfs_statfs, + .put_super = squashfs_put_super, + .remount_fs = squashfs_remount +}; + +static struct export_operations squashfs_export_ops = { + .fh_to_dentry = squashfs_fh_to_dentry, + .fh_to_parent = squashfs_fh_to_parent, + .get_parent = squashfs_get_parent +}; + +SQSH_EXTERN const struct address_space_operations squashfs_symlink_aops = { + .readpage = squashfs_symlink_readpage +}; + +SQSH_EXTERN const struct address_space_operations squashfs_aops = { + .readpage = squashfs_readpage +}; + +static const struct file_operations squashfs_dir_ops = { + .read = generic_read_dir, + .readdir = squashfs_readdir +}; + +SQSH_EXTERN struct inode_operations squashfs_dir_inode_ops = { + .lookup = squashfs_lookup +}; + + +static struct buffer_head *get_block_length(struct super_block *s, + int *cur_index, int *offset, int *c_byte) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + unsigned short temp; + struct buffer_head *bh; + + if (!(bh = sb_bread(s, *cur_index))) + goto out; + + if (msblk->devblksize - *offset == 1) { + if (msblk->swap) + ((unsigned char *) &temp)[1] = *((unsigned char *) + (bh->b_data + *offset)); + else + ((unsigned char *) &temp)[0] = *((unsigned char *) + (bh->b_data + *offset)); + brelse(bh); + if (!(bh = sb_bread(s, ++(*cur_index)))) + goto out; + if (msblk->swap) + ((unsigned char *) &temp)[0] = *((unsigned char *) + bh->b_data); + else + ((unsigned char *) &temp)[1] = *((unsigned char *) + bh->b_data); + *c_byte = temp; + *offset = 1; + } else { + if (msblk->swap) { + ((unsigned char *) &temp)[1] = *((unsigned char *) + (bh->b_data + *offset)); + ((unsigned char *) &temp)[0] = *((unsigned char *) + (bh->b_data + *offset + 1)); + } else { + ((unsigned char *) &temp)[0] = *((unsigned char *) + (bh->b_data + *offset)); + ((unsigned char *) &temp)[1] = *((unsigned char *) + (bh->b_data + *offset + 1)); + } + *c_byte = temp; + *offset += 2; + } + + if (SQUASHFS_CHECK_DATA(msblk->sblk.flags)) { + if (*offset == msblk->devblksize) { + brelse(bh); + if (!(bh = sb_bread(s, ++(*cur_index)))) + goto out; + *offset = 0; + } + if (*((unsigned char *) (bh->b_data + *offset)) != + SQUASHFS_MARKER_BYTE) { + ERROR("Metadata block marker corrupt @ %x\n", + *cur_index); + brelse(bh); + goto out; + } + (*offset)++; + } + return bh; + +out: + return NULL; +} + + +SQSH_EXTERN unsigned int squashfs_read_data(struct super_block *s, char *buffer, + long long index, unsigned int length, + long long *next_index, int srclength) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + struct buffer_head **bh; + unsigned int offset = index & ((1 << msblk->devblksize_log2) - 1); + unsigned int cur_index = index >> msblk->devblksize_log2; + int bytes, avail_bytes, b = 0, k = 0; + unsigned int compressed; + unsigned int c_byte = length; + + bh = kmalloc(((sblk->block_size >> msblk->devblksize_log2) + 1) * + sizeof(struct buffer_head *), GFP_KERNEL); + if (bh == NULL) + goto read_failure; + + if (c_byte) { + bytes = -offset; + compressed = SQUASHFS_COMPRESSED_BLOCK(c_byte); + c_byte = SQUASHFS_COMPRESSED_SIZE_BLOCK(c_byte); + + TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n", index, + compressed ? "" : "un", (unsigned int) c_byte, srclength); + + if (c_byte > srclength || index < 0 || (index + c_byte) > sblk->bytes_used) + goto read_failure; + + for (b = 0; bytes < (int) c_byte; b++, cur_index++) { + bh[b] = sb_getblk(s, cur_index); + if (bh[b] == NULL) + goto block_release; + bytes += msblk->devblksize; + } + ll_rw_block(READ, b, bh); + } else { + if (index < 0 || (index + 2) > sblk->bytes_used) + goto read_failure; + + bh[0] = get_block_length(s, &cur_index, &offset, &c_byte); + if (bh[0] == NULL) + goto read_failure; + b = 1; + + bytes = msblk->devblksize - offset; + compressed = SQUASHFS_COMPRESSED(c_byte); + c_byte = SQUASHFS_COMPRESSED_SIZE(c_byte); + + TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed + ? "" : "un", (unsigned int) c_byte); + + if (c_byte > srclength || (index + c_byte) > sblk->bytes_used) + goto block_release; + + for (; bytes < c_byte; b++) { + bh[b] = sb_getblk(s, ++cur_index); + if (bh[b] == NULL) + goto block_release; + bytes += msblk->devblksize; + } + ll_rw_block(READ, b - 1, bh + 1); + } + + if (compressed) { + int zlib_err = 0; + + /* + * uncompress block + */ + + mutex_lock(&msblk->read_data_mutex); + + msblk->stream.next_out = buffer; + msblk->stream.avail_out = srclength; + + for (bytes = 0; k < b; k++) { + avail_bytes = min(c_byte - bytes, msblk->devblksize - offset); + + wait_on_buffer(bh[k]); + if (!buffer_uptodate(bh[k])) + goto release_mutex; + + msblk->stream.next_in = bh[k]->b_data + offset; + msblk->stream.avail_in = avail_bytes; + + if (k == 0) { + zlib_err = zlib_inflateInit(&msblk->stream); + if (zlib_err != Z_OK) { + ERROR("zlib_inflateInit returned unexpected result 0x%x," + " srclength %d\n", zlib_err, srclength); + goto release_mutex; + } + + if (avail_bytes == 0) { + offset = 0; + brelse(bh[k]); + continue; + } + } + + zlib_err = zlib_inflate(&msblk->stream, Z_NO_FLUSH); + if (zlib_err != Z_OK && zlib_err != Z_STREAM_END) { + ERROR("zlib_inflate returned unexpected result 0x%x," + " srclength %d, avail_in %d, avail_out %d\n", zlib_err, + srclength, msblk->stream.avail_in, msblk->stream.avail_out); + goto release_mutex; + } + + bytes += avail_bytes; + offset = 0; + brelse(bh[k]); + } + + if (zlib_err != Z_STREAM_END) + goto release_mutex; + + zlib_err = zlib_inflateEnd(&msblk->stream); + if (zlib_err != Z_OK) { + ERROR("zlib_inflateEnd returned unexpected result 0x%x," + " srclength %d\n", zlib_err, srclength); + goto release_mutex; + } + bytes = msblk->stream.total_out; + mutex_unlock(&msblk->read_data_mutex); + } else { + int i; + + for(i = 0; i < b; i++) { + wait_on_buffer(bh[i]); + if (!buffer_uptodate(bh[i])) + goto block_release; + } + + for (bytes = 0; k < b; k++) { + avail_bytes = min(c_byte - bytes, msblk->devblksize - offset); + + memcpy(buffer + bytes, bh[k]->b_data + offset, avail_bytes); + bytes += avail_bytes; + offset = 0; + brelse(bh[k]); + } + } + + if (next_index) + *next_index = index + c_byte + (length ? 0 : + (SQUASHFS_CHECK_DATA(msblk->sblk.flags) ? 3 : 2)); + + kfree(bh); + return bytes; + +release_mutex: + mutex_unlock(&msblk->read_data_mutex); + +block_release: + for (; k < b; k++) + brelse(bh[k]); + +read_failure: + ERROR("sb_bread failed reading block 0x%x\n", cur_index); + kfree(bh); + return 0; +} + + +static struct squashfs_cache_entry *squashfs_cache_get(struct super_block *s, + struct squashfs_cache *cache, long long block, int length) +{ + int i, n; + struct squashfs_cache_entry *entry; + + spin_lock(&cache->lock); + + while (1) { + for (i = 0; i < cache->entries && cache->entry[i].block != block; i++); + + if (i == cache->entries) { + if (cache->unused_blks == 0) { + cache->waiting ++; + spin_unlock(&cache->lock); + wait_event(cache->wait_queue, cache->unused_blks); + spin_lock(&cache->lock); + cache->waiting --; + continue; + } + + i = cache->next_blk; + for (n = 0; n < cache->entries; n++) { + if (cache->entry[i].locked == 0) + break; + i = (i + 1) % cache->entries; + } + + cache->next_blk = (i + 1) % cache->entries; + entry = &cache->entry[i]; + + cache->unused_blks --; + entry->block = block; + entry->locked = 1; + entry->pending = 1; + entry->waiting = 0; + entry->error = 0; + spin_unlock(&cache->lock); + + entry->length = squashfs_read_data(s, entry->data, + block, length, &entry->next_index, cache->block_size); + + spin_lock(&cache->lock); + + if (entry->length == 0) + entry->error = 1; + + entry->pending = 0; + spin_unlock(&cache->lock); + if (entry->waiting) + wake_up_all(&entry->wait_queue); + goto out; + } + + entry = &cache->entry[i]; + if (entry->locked == 0) + cache->unused_blks --; + entry->locked++; + + if (entry->pending) { + entry->waiting ++; + spin_unlock(&cache->lock); + wait_event(entry->wait_queue, !entry->pending); + goto out; + } + + spin_unlock(&cache->lock); + goto out; + } + +out: + TRACE("Got %s %d, start block %lld, locked %d, error %d\n", i, + cache->name, entry->block, entry->locked, entry->error); + if (entry->error) + ERROR("Unable to read %s cache entry [%llx]\n", cache->name, block); + return entry; +} + + +static void squashfs_cache_put(struct squashfs_cache *cache, + struct squashfs_cache_entry *entry) +{ + spin_lock(&cache->lock); + entry->locked --; + if (entry->locked == 0) { + cache->unused_blks ++; + spin_unlock(&cache->lock); + if (cache->waiting) + wake_up(&cache->wait_queue); + } else + spin_unlock(&cache->lock); +} + + +static void squashfs_cache_delete(struct squashfs_cache *cache) +{ + int i; + + if (cache == NULL) + return; + + for (i = 0; i < cache->entries; i++) + if (cache->entry[i].data) { + if (cache->use_vmalloc) + vfree(cache->entry[i].data); + else + kfree(cache->entry[i].data); + } + + kfree(cache); +} + + +static struct squashfs_cache *squashfs_cache_init(char *name, int entries, + int block_size, int use_vmalloc) +{ + int i; + struct squashfs_cache *cache = kzalloc(sizeof(struct squashfs_cache) + + entries * sizeof(struct squashfs_cache_entry), GFP_KERNEL); + if (cache == NULL) { + ERROR("Failed to allocate %s cache\n", name); + goto failed; + } + + cache->next_blk = 0; + cache->unused_blks = entries; + cache->entries = entries; + cache->block_size = block_size; + cache->use_vmalloc = use_vmalloc; + cache->name = name; + cache->waiting = 0; + spin_lock_init(&cache->lock); + init_waitqueue_head(&cache->wait_queue); + + for (i = 0; i < entries; i++) { + init_waitqueue_head(&cache->entry[i].wait_queue); + cache->entry[i].block = SQUASHFS_INVALID_BLK; + cache->entry[i].data = use_vmalloc ? vmalloc(block_size) : + kmalloc(block_size, GFP_KERNEL); + if (cache->entry[i].data == NULL) { + ERROR("Failed to allocate %s cache entry\n", name); + goto cleanup; + } + } + + return cache; + +cleanup: + squashfs_cache_delete(cache); +failed: + return NULL; +} + + +SQSH_EXTERN int squashfs_get_cached_block(struct super_block *s, void *buffer, + long long block, unsigned int offset, + int length, long long *next_block, + unsigned int *next_offset) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + int bytes, return_length = length; + struct squashfs_cache_entry *entry; + + TRACE("Entered squashfs_get_cached_block [%llx:%x]\n", block, offset); + + while (1) { + entry = squashfs_cache_get(s, msblk->block_cache, block, 0); + bytes = entry->length - offset; + + if (entry->error || bytes < 1) { + return_length = 0; + goto finish; + } else if (bytes >= length) { + if (buffer) + memcpy(buffer, entry->data + offset, length); + if (entry->length - offset == length) { + *next_block = entry->next_index; + *next_offset = 0; + } else { + *next_block = block; + *next_offset = offset + length; + } + goto finish; + } else { + if (buffer) { + memcpy(buffer, entry->data + offset, bytes); + buffer = (char *) buffer + bytes; + } + block = entry->next_index; + squashfs_cache_put(msblk->block_cache, entry); + length -= bytes; + offset = 0; + } + } + +finish: + squashfs_cache_put(msblk->block_cache, entry); + return return_length; +} + + +static int get_fragment_location(struct super_block *s, unsigned int fragment, + long long *fragment_start_block, + unsigned int *fragment_size) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + long long start_block = + msblk->fragment_index[SQUASHFS_FRAGMENT_INDEX(fragment)]; + int offset = SQUASHFS_FRAGMENT_INDEX_OFFSET(fragment); + struct squashfs_fragment_entry fragment_entry; + + if (msblk->swap) { + struct squashfs_fragment_entry sfragment_entry; + + if (!squashfs_get_cached_block(s, &sfragment_entry, start_block, offset, + sizeof(sfragment_entry), &start_block, &offset)) + goto out; + SQUASHFS_SWAP_FRAGMENT_ENTRY(&fragment_entry, &sfragment_entry); + } else + if (!squashfs_get_cached_block(s, &fragment_entry, start_block, offset, + sizeof(fragment_entry), &start_block, &offset)) + goto out; + + *fragment_start_block = fragment_entry.start_block; + *fragment_size = fragment_entry.size; + + return 1; + +out: + return 0; +} + + +SQSH_EXTERN void release_cached_fragment(struct squashfs_sb_info *msblk, + struct squashfs_cache_entry *fragment) +{ + squashfs_cache_put(msblk->fragment_cache, fragment); +} + + +SQSH_EXTERN +struct squashfs_cache_entry *get_cached_fragment(struct super_block *s, + long long start_block, int length) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + + return squashfs_cache_get(s, msblk->fragment_cache, start_block, length); +} + + +static void squashfs_new_inode(struct squashfs_sb_info *msblk, struct inode *i, + struct squashfs_base_inode_header *inodeb) +{ + i->i_ino = inodeb->inode_number; + i->i_mtime.tv_sec = inodeb->mtime; + i->i_atime.tv_sec = inodeb->mtime; + i->i_ctime.tv_sec = inodeb->mtime; + i->i_uid = msblk->uid[inodeb->uid]; + i->i_mode = inodeb->mode; + i->i_size = 0; + + if (inodeb->guid == SQUASHFS_GUIDS) + i->i_gid = i->i_uid; + else + i->i_gid = msblk->guid[inodeb->guid]; +} + + +static squashfs_inode_t squashfs_inode_lookup(struct super_block *s, int ino) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + long long start = msblk->inode_lookup_table[SQUASHFS_LOOKUP_BLOCK(ino - 1)]; + int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino - 1); + squashfs_inode_t inode; + + TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino); + + if (msblk->swap) { + squashfs_inode_t sinode; + + if (!squashfs_get_cached_block(s, &sinode, start, offset, + sizeof(sinode), &start, &offset)) + goto out; + SQUASHFS_SWAP_INODE_T((&inode), &sinode); + } else if (!squashfs_get_cached_block(s, &inode, start, offset, + sizeof(inode), &start, &offset)) + goto out; + + TRACE("squashfs_inode_lookup, inode = 0x%llx\n", inode); + + return inode; + +out: + return SQUASHFS_INVALID_BLK; +} + + + +static struct dentry *squashfs_export_iget(struct super_block *s, + unsigned int inode_number) +{ + squashfs_inode_t inode; + struct dentry *dentry = ERR_PTR(-ENOENT); + + TRACE("Entered squashfs_export_iget\n"); + + inode = squashfs_inode_lookup(s, inode_number); + if(inode != SQUASHFS_INVALID_BLK) + dentry = d_obtain_alias(squashfs_iget(s, inode, inode_number)); + + return dentry; +} + + +static struct dentry *squashfs_fh_to_dentry(struct super_block *s, + struct fid *fid, int fh_len, int fh_type) +{ + if((fh_type != FILEID_INO32_GEN && fh_type != FILEID_INO32_GEN_PARENT) || + fh_len < 2) + return NULL; + + return squashfs_export_iget(s, fid->i32.ino); +} + + +static struct dentry *squashfs_fh_to_parent(struct super_block *s, + struct fid *fid, int fh_len, int fh_type) +{ + if(fh_type != FILEID_INO32_GEN_PARENT || fh_len < 4) + return NULL; + + return squashfs_export_iget(s, fid->i32.parent_ino); +} + + +static struct dentry *squashfs_get_parent(struct dentry *child) +{ + struct inode *i = child->d_inode; + + TRACE("Entered squashfs_get_parent\n"); + + return squashfs_export_iget(i->i_sb, SQUASHFS_I(i)->u.s2.parent_inode); +} + + +SQSH_EXTERN struct inode *squashfs_iget(struct super_block *s, + squashfs_inode_t inode, unsigned int inode_number) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + struct inode *i = iget_locked(s, inode_number); + + TRACE("Entered squashfs_iget\n"); + + if(i && (i->i_state & I_NEW)) { + (msblk->read_inode)(i, inode); + unlock_new_inode(i); + } + + return i; +} + + +static int squashfs_read_inode(struct inode *i, squashfs_inode_t inode) +{ + struct super_block *s = i->i_sb; + struct squashfs_sb_info *msblk = s->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + long long block = SQUASHFS_INODE_BLK(inode) + sblk->inode_table_start; + unsigned int offset = SQUASHFS_INODE_OFFSET(inode); + long long next_block; + unsigned int next_offset; + union squashfs_inode_header id, sid; + struct squashfs_base_inode_header *inodeb = &id.base, *sinodeb = &sid.base; + + TRACE("Entered squashfs_read_inode\n"); + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodeb, block, offset, + sizeof(*sinodeb), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_BASE_INODE_HEADER(inodeb, sinodeb, sizeof(*sinodeb)); + } else + if (!squashfs_get_cached_block(s, inodeb, block, offset, + sizeof(*inodeb), &next_block, &next_offset)) + goto failed_read; + + squashfs_new_inode(msblk, i, inodeb); + + switch(inodeb->inode_type) { + case SQUASHFS_FILE_TYPE: { + unsigned int frag_size; + long long frag_blk; + struct squashfs_reg_inode_header *inodep = &id.reg; + struct squashfs_reg_inode_header *sinodep = &sid.reg; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_REG_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + frag_blk = SQUASHFS_INVALID_BLK; + + if (inodep->fragment != SQUASHFS_INVALID_FRAG) + if(!get_fragment_location(s, inodep->fragment, &frag_blk, + &frag_size)) + goto failed_read; + + i->i_nlink = 1; + i->i_size = inodep->file_size; + i->i_fop = &generic_ro_fops; + i->i_mode |= S_IFREG; + i->i_blocks = ((i->i_size - 1) >> 9) + 1; + SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk; + SQUASHFS_I(i)->u.s1.fragment_size = frag_size; + SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset; + SQUASHFS_I(i)->start_block = inodep->start_block; + SQUASHFS_I(i)->u.s1.block_list_start = next_block; + SQUASHFS_I(i)->offset = next_offset; + i->i_data.a_ops = &squashfs_aops; + + TRACE("File inode %x:%x, start_block %llx, " + "block_list_start %llx, offset %x\n", + SQUASHFS_INODE_BLK(inode), offset, + inodep->start_block, next_block, + next_offset); + break; + } + case SQUASHFS_LREG_TYPE: { + unsigned int frag_size; + long long frag_blk; + struct squashfs_lreg_inode_header *inodep = &id.lreg; + struct squashfs_lreg_inode_header *sinodep = &sid.lreg; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_LREG_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + frag_blk = SQUASHFS_INVALID_BLK; + + if (inodep->fragment != SQUASHFS_INVALID_FRAG) + if (!get_fragment_location(s, inodep->fragment, &frag_blk, + &frag_size)) + goto failed_read; + + i->i_nlink = inodep->nlink; + i->i_size = inodep->file_size; + i->i_fop = &generic_ro_fops; + i->i_mode |= S_IFREG; + i->i_blocks = ((i->i_size - 1) >> 9) + 1; + SQUASHFS_I(i)->u.s1.fragment_start_block = frag_blk; + SQUASHFS_I(i)->u.s1.fragment_size = frag_size; + SQUASHFS_I(i)->u.s1.fragment_offset = inodep->offset; + SQUASHFS_I(i)->start_block = inodep->start_block; + SQUASHFS_I(i)->u.s1.block_list_start = next_block; + SQUASHFS_I(i)->offset = next_offset; + i->i_data.a_ops = &squashfs_aops; + + TRACE("File inode %x:%x, start_block %llx, " + "block_list_start %llx, offset %x\n", + SQUASHFS_INODE_BLK(inode), offset, + inodep->start_block, next_block, + next_offset); + break; + } + case SQUASHFS_DIR_TYPE: { + struct squashfs_dir_inode_header *inodep = &id.dir; + struct squashfs_dir_inode_header *sinodep = &sid.dir; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_DIR_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + i->i_nlink = inodep->nlink; + i->i_size = inodep->file_size; + i->i_op = &squashfs_dir_inode_ops; + i->i_fop = &squashfs_dir_ops; + i->i_mode |= S_IFDIR; + SQUASHFS_I(i)->start_block = inodep->start_block; + SQUASHFS_I(i)->offset = inodep->offset; + SQUASHFS_I(i)->u.s2.directory_index_count = 0; + SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode; + + TRACE("Directory inode %x:%x, start_block %x, offset " + "%x\n", SQUASHFS_INODE_BLK(inode), + offset, inodep->start_block, + inodep->offset); + break; + } + case SQUASHFS_LDIR_TYPE: { + struct squashfs_ldir_inode_header *inodep = &id.ldir; + struct squashfs_ldir_inode_header *sinodep = &sid.ldir; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_LDIR_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + i->i_nlink = inodep->nlink; + i->i_size = inodep->file_size; + i->i_op = &squashfs_dir_inode_ops; + i->i_fop = &squashfs_dir_ops; + i->i_mode |= S_IFDIR; + SQUASHFS_I(i)->start_block = inodep->start_block; + SQUASHFS_I(i)->offset = inodep->offset; + SQUASHFS_I(i)->u.s2.directory_index_start = next_block; + SQUASHFS_I(i)->u.s2.directory_index_offset = next_offset; + SQUASHFS_I(i)->u.s2.directory_index_count = inodep->i_count; + SQUASHFS_I(i)->u.s2.parent_inode = inodep->parent_inode; + + TRACE("Long directory inode %x:%x, start_block %x, offset %x\n", + SQUASHFS_INODE_BLK(inode), offset, + inodep->start_block, inodep->offset); + break; + } + case SQUASHFS_SYMLINK_TYPE: { + struct squashfs_symlink_inode_header *inodep = &id.symlink; + struct squashfs_symlink_inode_header *sinodep = &sid.symlink; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_SYMLINK_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + i->i_nlink = inodep->nlink; + i->i_size = inodep->symlink_size; + i->i_op = &page_symlink_inode_operations; + i->i_data.a_ops = &squashfs_symlink_aops; + i->i_mode |= S_IFLNK; + SQUASHFS_I(i)->start_block = next_block; + SQUASHFS_I(i)->offset = next_offset; + + TRACE("Symbolic link inode %x:%x, start_block %llx, offset %x\n", + SQUASHFS_INODE_BLK(inode), offset, + next_block, next_offset); + break; + } + case SQUASHFS_BLKDEV_TYPE: + case SQUASHFS_CHRDEV_TYPE: { + struct squashfs_dev_inode_header *inodep = &id.dev; + struct squashfs_dev_inode_header *sinodep = &sid.dev; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_DEV_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + i->i_nlink = inodep->nlink; + i->i_mode |= (inodeb->inode_type == SQUASHFS_CHRDEV_TYPE) ? + S_IFCHR : S_IFBLK; + init_special_inode(i, i->i_mode, old_decode_dev(inodep->rdev)); + + TRACE("Device inode %x:%x, rdev %x\n", + SQUASHFS_INODE_BLK(inode), offset, inodep->rdev); + break; + } + case SQUASHFS_FIFO_TYPE: + case SQUASHFS_SOCKET_TYPE: { + struct squashfs_ipc_inode_header *inodep = &id.ipc; + struct squashfs_ipc_inode_header *sinodep = &sid.ipc; + + if (msblk->swap) { + if (!squashfs_get_cached_block(s, sinodep, block, offset, + sizeof(*sinodep), &next_block, &next_offset)) + goto failed_read; + SQUASHFS_SWAP_IPC_INODE_HEADER(inodep, sinodep); + } else + if (!squashfs_get_cached_block(s, inodep, block, offset, + sizeof(*inodep), &next_block, &next_offset)) + goto failed_read; + + i->i_nlink = inodep->nlink; + i->i_mode |= (inodeb->inode_type == SQUASHFS_FIFO_TYPE) + ? S_IFIFO : S_IFSOCK; + init_special_inode(i, i->i_mode, 0); + break; + } + default: + ERROR("Unknown inode type %d in squashfs_iget!\n", + inodeb->inode_type); + goto failed_read1; + } + + return 1; + +failed_read: + ERROR("Unable to read inode [%llx:%x]\n", block, offset); + +failed_read1: + make_bad_inode(i); + return 0; +} + + +static int read_inode_lookup_table(struct super_block *s) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(sblk->inodes); + + TRACE("In read_inode_lookup_table, length %d\n", length); + + /* Allocate inode lookup table */ + msblk->inode_lookup_table = kmalloc(length, GFP_KERNEL); + if (msblk->inode_lookup_table == NULL) { + ERROR("Failed to allocate inode lookup table\n"); + return 0; + } + + if (!squashfs_read_data(s, (char *) msblk->inode_lookup_table, + sblk->lookup_table_start, length | + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length)) { + ERROR("unable to read inode lookup table\n"); + return 0; + } + + if (msblk->swap) { + int i; + long long block; + + for (i = 0; i < SQUASHFS_LOOKUP_BLOCKS(sblk->inodes); i++) { + /* XXX */ + SQUASHFS_SWAP_LOOKUP_BLOCKS((&block), + &msblk->inode_lookup_table[i], 1); + msblk->inode_lookup_table[i] = block; + } + } + + return 1; +} + + +static int read_fragment_index_table(struct super_block *s) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + unsigned int length = SQUASHFS_FRAGMENT_INDEX_BYTES(sblk->fragments); + + if(length == 0) + return 1; + + /* Allocate fragment index table */ + msblk->fragment_index = kmalloc(length, GFP_KERNEL); + if (msblk->fragment_index == NULL) { + ERROR("Failed to allocate fragment index table\n"); + return 0; + } + + if (!squashfs_read_data(s, (char *) msblk->fragment_index, + sblk->fragment_table_start, length | + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length)) { + ERROR("unable to read fragment index table\n"); + return 0; + } + + if (msblk->swap) { + int i; + long long fragment; + + for (i = 0; i < SQUASHFS_FRAGMENT_INDEXES(sblk->fragments); i++) { + /* XXX */ + SQUASHFS_SWAP_FRAGMENT_INDEXES((&fragment), + &msblk->fragment_index[i], 1); + msblk->fragment_index[i] = fragment; + } + } + + return 1; +} + + +static int supported_squashfs_filesystem(struct squashfs_sb_info *msblk, int silent) +{ + struct squashfs_super_block *sblk = &msblk->sblk; + + msblk->read_inode = squashfs_read_inode; + msblk->read_blocklist = read_blocklist; + msblk->read_fragment_index_table = read_fragment_index_table; + + if (sblk->s_major == 1) { + if (!squashfs_1_0_supported(msblk)) { + SERROR("Major/Minor mismatch, Squashfs 1.0 filesystems " + "are unsupported\n"); + SERROR("Please recompile with Squashfs 1.0 support enabled\n"); + return 0; + } + } else if (sblk->s_major == 2) { + if (!squashfs_2_0_supported(msblk)) { + SERROR("Major/Minor mismatch, Squashfs 2.0 filesystems " + "are unsupported\n"); + SERROR("Please recompile with Squashfs 2.0 support enabled\n"); + return 0; + } + } else if(sblk->s_major != SQUASHFS_MAJOR || sblk->s_minor > + SQUASHFS_MINOR) { + SERROR("Major/Minor mismatch, trying to mount newer %d.%d " + "filesystem\n", sblk->s_major, sblk->s_minor); + SERROR("Please update your kernel\n"); + return 0; + } + + return 1; +} + + +static int squashfs_fill_super(struct super_block *s, void *data, int silent) +{ + struct squashfs_sb_info *msblk; + struct squashfs_super_block *sblk; + char b[BDEVNAME_SIZE]; + struct inode *root; + + TRACE("Entered squashfs_fill_superblock\n"); + + s->s_fs_info = kzalloc(sizeof(struct squashfs_sb_info), GFP_KERNEL); + if (s->s_fs_info == NULL) { + ERROR("Failed to allocate superblock\n"); + goto failure; + } + msblk = s->s_fs_info; + + msblk->stream.workspace = vmalloc(zlib_inflate_workspacesize()); + if (msblk->stream.workspace == NULL) { + ERROR("Failed to allocate zlib workspace\n"); + goto failure; + } + sblk = &msblk->sblk; + + msblk->devblksize = sb_min_blocksize(s, BLOCK_SIZE); + msblk->devblksize_log2 = ffz(~msblk->devblksize); + + mutex_init(&msblk->read_data_mutex); + mutex_init(&msblk->read_page_mutex); + mutex_init(&msblk->meta_index_mutex); + + /* sblk->bytes_used is checked in squashfs_read_data to ensure reads are not + * beyond filesystem end. As we're using squashfs_read_data to read sblk here, + * first set sblk->bytes_used to a useful value */ + sblk->bytes_used = sizeof(struct squashfs_super_block); + if (!squashfs_read_data(s, (char *) sblk, SQUASHFS_START, + sizeof(struct squashfs_super_block) | + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, sizeof(struct squashfs_super_block))) { + SERROR("unable to read superblock\n"); + goto failed_mount; + } + + /* Check it is a SQUASHFS superblock */ + if ((s->s_magic = sblk->s_magic) != SQUASHFS_MAGIC) { + if (sblk->s_magic == SQUASHFS_MAGIC_SWAP) { + struct squashfs_super_block ssblk; + + WARNING("Mounting a different endian SQUASHFS filesystem on %s\n", + bdevname(s->s_bdev, b)); + + SQUASHFS_SWAP_SUPER_BLOCK(&ssblk, sblk); + memcpy(sblk, &ssblk, sizeof(struct squashfs_super_block)); + msblk->swap = 1; + } else { + SERROR("Can't find a SQUASHFS superblock on %s\n", + bdevname(s->s_bdev, b)); + goto failed_mount; + } + } + + /* Check the MAJOR & MINOR versions */ + if(!supported_squashfs_filesystem(msblk, silent)) + goto failed_mount; + + /* Check the filesystem does not extend beyond the end of the + block device */ + if(sblk->bytes_used < 0 || sblk->bytes_used > i_size_read(s->s_bdev->bd_inode)) + goto failed_mount; + + /* Check the root inode for sanity */ + if (SQUASHFS_INODE_OFFSET(sblk->root_inode) > SQUASHFS_METADATA_SIZE) + goto failed_mount; + + TRACE("Found valid superblock on %s\n", bdevname(s->s_bdev, b)); + TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(sblk->flags) + ? "un" : ""); + TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(sblk->flags) + ? "un" : ""); + TRACE("Check data is %spresent in the filesystem\n", + SQUASHFS_CHECK_DATA(sblk->flags) ? "" : "not "); + TRACE("Filesystem size %lld bytes\n", sblk->bytes_used); + TRACE("Block size %d\n", sblk->block_size); + TRACE("Number of inodes %d\n", sblk->inodes); + if (sblk->s_major > 1) + TRACE("Number of fragments %d\n", sblk->fragments); + TRACE("Number of uids %d\n", sblk->no_uids); + TRACE("Number of gids %d\n", sblk->no_guids); + TRACE("sblk->inode_table_start %llx\n", sblk->inode_table_start); + TRACE("sblk->directory_table_start %llx\n", sblk->directory_table_start); + if (sblk->s_major > 1) + TRACE("sblk->fragment_table_start %llx\n", sblk->fragment_table_start); + TRACE("sblk->uid_start %llx\n", sblk->uid_start); + + s->s_maxbytes = MAX_LFS_FILESIZE; + s->s_flags |= MS_RDONLY; + s->s_op = &squashfs_super_ops; + + msblk->block_cache = squashfs_cache_init("metadata", SQUASHFS_CACHED_BLKS, + SQUASHFS_METADATA_SIZE, 0); + if (msblk->block_cache == NULL) + goto failed_mount; + + /* Allocate read_page block */ + msblk->read_page = vmalloc(sblk->block_size); + if (msblk->read_page == NULL) { + ERROR("Failed to allocate read_page block\n"); + goto failed_mount; + } + + /* Allocate uid and gid tables */ + msblk->uid = kmalloc((sblk->no_uids + sblk->no_guids) * + sizeof(unsigned int), GFP_KERNEL); + if (msblk->uid == NULL) { + ERROR("Failed to allocate uid/gid table\n"); + goto failed_mount; + } + msblk->guid = msblk->uid + sblk->no_uids; + + if (msblk->swap) { + unsigned int suid[sblk->no_uids + sblk->no_guids]; + + if (!squashfs_read_data(s, (char *) &suid, sblk->uid_start, + ((sblk->no_uids + sblk->no_guids) * + sizeof(unsigned int)) | + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, (sblk->no_uids + sblk->no_guids) * sizeof(unsigned int))) { + ERROR("unable to read uid/gid table\n"); + goto failed_mount; + } + + SQUASHFS_SWAP_DATA(msblk->uid, suid, (sblk->no_uids + + sblk->no_guids), (sizeof(unsigned int) * 8)); + } else + if (!squashfs_read_data(s, (char *) msblk->uid, sblk->uid_start, + ((sblk->no_uids + sblk->no_guids) * + sizeof(unsigned int)) | + SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, (sblk->no_uids + sblk->no_guids) * sizeof(unsigned int))) { + ERROR("unable to read uid/gid table\n"); + goto failed_mount; + } + + + if (sblk->s_major == 1 && squashfs_1_0_supported(msblk)) + goto allocate_root; + + msblk->fragment_cache = squashfs_cache_init("fragment", + SQUASHFS_CACHED_FRAGMENTS, sblk->block_size, 1); + if (msblk->fragment_cache == NULL) + goto failed_mount; + + /* Allocate and read fragment index table */ + if (msblk->read_fragment_index_table(s) == 0) + goto failed_mount; + + if(sblk->s_major < 3 || sblk->lookup_table_start == SQUASHFS_INVALID_BLK) + goto allocate_root; + + /* Allocate and read inode lookup table */ + if (read_inode_lookup_table(s) == 0) + goto failed_mount; + + s->s_export_op = &squashfs_export_ops; + +allocate_root: + root = new_inode(s); + if ((msblk->read_inode)(root, sblk->root_inode) == 0) + goto failed_mount; + insert_inode_hash(root); + + s->s_root = d_alloc_root(root); + if (s->s_root == NULL) { + ERROR("Root inode create failed\n"); + iput(root); + goto failed_mount; + } + + TRACE("Leaving squashfs_fill_super\n"); + return 0; + +failed_mount: + kfree(msblk->inode_lookup_table); + kfree(msblk->fragment_index); + squashfs_cache_delete(msblk->fragment_cache); + kfree(msblk->uid); + vfree(msblk->read_page); + squashfs_cache_delete(msblk->block_cache); + kfree(msblk->fragment_index_2); + vfree(msblk->stream.workspace); + kfree(s->s_fs_info); + s->s_fs_info = NULL; + return -EINVAL; + +failure: + return -ENOMEM; +} + + +static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + + TRACE("Entered squashfs_statfs\n"); + + buf->f_type = SQUASHFS_MAGIC; + buf->f_bsize = sblk->block_size; + buf->f_blocks = ((sblk->bytes_used - 1) >> sblk->block_log) + 1; + buf->f_bfree = buf->f_bavail = 0; + buf->f_files = sblk->inodes; + buf->f_ffree = 0; + buf->f_namelen = SQUASHFS_NAME_LEN; + + return 0; +} + + +static int squashfs_symlink_readpage(struct file *file, struct page *page) +{ + struct inode *inode = page->mapping->host; + int index = page->index << PAGE_CACHE_SHIFT, length, bytes, avail_bytes; + long long block = SQUASHFS_I(inode)->start_block; + int offset = SQUASHFS_I(inode)->offset; + void *pageaddr = kmap(page); + + TRACE("Entered squashfs_symlink_readpage, page index %ld, start block " + "%llx, offset %x\n", page->index, + SQUASHFS_I(inode)->start_block, + SQUASHFS_I(inode)->offset); + + for (length = 0; length < index; length += bytes) { + bytes = squashfs_get_cached_block(inode->i_sb, NULL, block, + offset, PAGE_CACHE_SIZE, &block, &offset); + if (bytes == 0) { + ERROR("Unable to read symbolic link [%llx:%x]\n", block, offset); + goto skip_read; + } + } + + if (length != index) { + ERROR("(squashfs_symlink_readpage) length != index\n"); + bytes = 0; + goto skip_read; + } + + avail_bytes = min_t(int, i_size_read(inode) - length, PAGE_CACHE_SIZE); + + bytes = squashfs_get_cached_block(inode->i_sb, pageaddr, block, offset, + avail_bytes, &block, &offset); + if (bytes == 0) + ERROR("Unable to read symbolic link [%llx:%x]\n", block, offset); + +skip_read: + memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes); + kunmap(page); + flush_dcache_page(page); + SetPageUptodate(page); + unlock_page(page); + + return 0; +} + + +static struct meta_index *locate_meta_index(struct inode *inode, int index, int offset) +{ + struct meta_index *meta = NULL; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + int i; + + mutex_lock(&msblk->meta_index_mutex); + + TRACE("locate_meta_index: index %d, offset %d\n", index, offset); + + if (msblk->meta_index == NULL) + goto not_allocated; + + for (i = 0; i < SQUASHFS_META_NUMBER; i ++) { + if (msblk->meta_index[i].inode_number == inode->i_ino && + msblk->meta_index[i].offset >= offset && + msblk->meta_index[i].offset <= index && + msblk->meta_index[i].locked == 0) { + TRACE("locate_meta_index: entry %d, offset %d\n", i, + msblk->meta_index[i].offset); + meta = &msblk->meta_index[i]; + offset = meta->offset; + } + } + + if (meta) + meta->locked = 1; + +not_allocated: + mutex_unlock(&msblk->meta_index_mutex); + + return meta; +} + + +static struct meta_index *empty_meta_index(struct inode *inode, int offset, int skip) +{ + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + struct meta_index *meta = NULL; + int i; + + mutex_lock(&msblk->meta_index_mutex); + + TRACE("empty_meta_index: offset %d, skip %d\n", offset, skip); + + if (msblk->meta_index == NULL) { + msblk->meta_index = kmalloc(sizeof(struct meta_index) * + SQUASHFS_META_NUMBER, GFP_KERNEL); + if (msblk->meta_index == NULL) { + ERROR("Failed to allocate meta_index\n"); + goto failed; + } + for (i = 0; i < SQUASHFS_META_NUMBER; i++) { + msblk->meta_index[i].inode_number = 0; + msblk->meta_index[i].locked = 0; + } + msblk->next_meta_index = 0; + } + + for (i = SQUASHFS_META_NUMBER; i && + msblk->meta_index[msblk->next_meta_index].locked; i --) + msblk->next_meta_index = (msblk->next_meta_index + 1) % + SQUASHFS_META_NUMBER; + + if (i == 0) { + TRACE("empty_meta_index: failed!\n"); + goto failed; + } + + TRACE("empty_meta_index: returned meta entry %d, %p\n", + msblk->next_meta_index, + &msblk->meta_index[msblk->next_meta_index]); + + meta = &msblk->meta_index[msblk->next_meta_index]; + msblk->next_meta_index = (msblk->next_meta_index + 1) % + SQUASHFS_META_NUMBER; + + meta->inode_number = inode->i_ino; + meta->offset = offset; + meta->skip = skip; + meta->entries = 0; + meta->locked = 1; + +failed: + mutex_unlock(&msblk->meta_index_mutex); + return meta; +} + + +static void release_meta_index(struct inode *inode, struct meta_index *meta) +{ + meta->locked = 0; + smp_mb(); +} + + +static int read_block_index(struct super_block *s, int blocks, char *block_list, + long long *start_block, int *offset) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + unsigned int *block_listp; + int block = 0; + + if (msblk->swap) { + char sblock_list[blocks << 2]; + + if (!squashfs_get_cached_block(s, sblock_list, *start_block, + *offset, blocks << 2, start_block, offset)) { + ERROR("Fail reading block list [%llx:%x]\n", *start_block, *offset); + goto failure; + } + SQUASHFS_SWAP_INTS(((unsigned int *)block_list), + ((unsigned int *)sblock_list), blocks); + } else { + if (!squashfs_get_cached_block(s, block_list, *start_block, + *offset, blocks << 2, start_block, offset)) { + ERROR("Fail reading block list [%llx:%x]\n", *start_block, *offset); + goto failure; + } + } + + for (block_listp = (unsigned int *) block_list; blocks; + block_listp++, blocks --) + block += SQUASHFS_COMPRESSED_SIZE_BLOCK(*block_listp); + + return block; + +failure: + return -1; +} + + +#define SIZE 256 + +static inline int calculate_skip(int blocks) { + int skip = (blocks - 1) / ((SQUASHFS_SLOTS * SQUASHFS_META_ENTRIES + 1) * SQUASHFS_META_INDEXES); + return skip >= 7 ? 7 : skip + 1; +} + + +static int get_meta_index(struct inode *inode, int index, + long long *index_block, int *index_offset, + long long *data_block, char *block_list) +{ + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + int skip = calculate_skip(i_size_read(inode) >> sblk->block_log); + int offset = 0; + struct meta_index *meta; + struct meta_entry *meta_entry; + long long cur_index_block = SQUASHFS_I(inode)->u.s1.block_list_start; + int cur_offset = SQUASHFS_I(inode)->offset; + long long cur_data_block = SQUASHFS_I(inode)->start_block; + int i; + + index /= SQUASHFS_META_INDEXES * skip; + + while (offset < index) { + meta = locate_meta_index(inode, index, offset + 1); + + if (meta == NULL) { + meta = empty_meta_index(inode, offset + 1, skip); + if (meta == NULL) + goto all_done; + } else { + if(meta->entries == 0) + goto failed; + /* XXX */ + offset = index < meta->offset + meta->entries ? index : + meta->offset + meta->entries - 1; + /* XXX */ + meta_entry = &meta->meta_entry[offset - meta->offset]; + cur_index_block = meta_entry->index_block + sblk->inode_table_start; + cur_offset = meta_entry->offset; + cur_data_block = meta_entry->data_block; + TRACE("get_meta_index: offset %d, meta->offset %d, " + "meta->entries %d\n", offset, meta->offset, meta->entries); + TRACE("get_meta_index: index_block 0x%llx, offset 0x%x" + " data_block 0x%llx\n", cur_index_block, + cur_offset, cur_data_block); + } + + for (i = meta->offset + meta->entries; i <= index && + i < meta->offset + SQUASHFS_META_ENTRIES; i++) { + int blocks = skip * SQUASHFS_META_INDEXES; + + while (blocks) { + int block = blocks > (SIZE >> 2) ? (SIZE >> 2) : blocks; + int res = read_block_index(inode->i_sb, block, block_list, + &cur_index_block, &cur_offset); + + if (res == -1) + goto failed; + + cur_data_block += res; + blocks -= block; + } + + meta_entry = &meta->meta_entry[i - meta->offset]; + meta_entry->index_block = cur_index_block - sblk->inode_table_start; + meta_entry->offset = cur_offset; + meta_entry->data_block = cur_data_block; + meta->entries ++; + offset ++; + } + + TRACE("get_meta_index: meta->offset %d, meta->entries %d\n", + meta->offset, meta->entries); + + release_meta_index(inode, meta); + } + +all_done: + *index_block = cur_index_block; + *index_offset = cur_offset; + *data_block = cur_data_block; + + return offset * SQUASHFS_META_INDEXES * skip; + +failed: + release_meta_index(inode, meta); + return -1; +} + + +static long long read_blocklist(struct inode *inode, int index, + int readahead_blks, char *block_list, + unsigned short **block_p, unsigned int *bsize) +{ + long long block_ptr; + int offset; + long long block; + int res = get_meta_index(inode, index, &block_ptr, &offset, &block, + block_list); + + TRACE("read_blocklist: res %d, index %d, block_ptr 0x%llx, offset" + " 0x%x, block 0x%llx\n", res, index, block_ptr, offset, block); + + if(res == -1) + goto failure; + + index -= res; + + while (index) { + int blocks = index > (SIZE >> 2) ? (SIZE >> 2) : index; + int res = read_block_index(inode->i_sb, blocks, block_list, + &block_ptr, &offset); + if (res == -1) + goto failure; + block += res; + index -= blocks; + } + + if (read_block_index(inode->i_sb, 1, block_list, &block_ptr, &offset) == -1) + goto failure; + *bsize = *((unsigned int *) block_list); + + return block; + +failure: + return 0; +} + + +static int squashfs_readpage(struct file *file, struct page *page) +{ + struct inode *inode = page->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + unsigned char *block_list = NULL; + long long block; + unsigned int bsize, i; + int bytes; + int index = page->index >> (sblk->block_log - PAGE_CACHE_SHIFT); + void *pageaddr; + struct squashfs_cache_entry *fragment = NULL; + char *data_ptr = msblk->read_page; + + int mask = (1 << (sblk->block_log - PAGE_CACHE_SHIFT)) - 1; + int start_index = page->index & ~mask; + int end_index = start_index | mask; + int file_end = i_size_read(inode) >> sblk->block_log; + int sparse = 0; + + TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n", + page->index, SQUASHFS_I(inode)->start_block); + + if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> + PAGE_CACHE_SHIFT)) + goto out; + + if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK + || index < file_end) { + block_list = kmalloc(SIZE, GFP_KERNEL); + if (block_list == NULL) { + ERROR("Failed to allocate block_list\n"); + goto error_out; + } + + block = (msblk->read_blocklist)(inode, index, 1, block_list, NULL, &bsize); + if (block == 0) + goto error_out; + + if (bsize == 0) { /* hole */ + bytes = index == file_end ? + (i_size_read(inode) & (sblk->block_size - 1)) : sblk->block_size; + sparse = 1; + } else { + mutex_lock(&msblk->read_page_mutex); + + bytes = squashfs_read_data(inode->i_sb, msblk->read_page, block, + bsize, NULL, sblk->block_size); + + if (bytes == 0) { + ERROR("Unable to read page, block %llx, size %x\n", block, bsize); + mutex_unlock(&msblk->read_page_mutex); + goto error_out; + } + } + } else { + fragment = get_cached_fragment(inode->i_sb, + SQUASHFS_I(inode)-> u.s1.fragment_start_block, + SQUASHFS_I(inode)->u.s1.fragment_size); + + if (fragment->error) { + ERROR("Unable to read page, block %llx, size %x\n", + SQUASHFS_I(inode)->u.s1.fragment_start_block, + (int) SQUASHFS_I(inode)->u.s1.fragment_size); + release_cached_fragment(msblk, fragment); + goto error_out; + } + bytes = i_size_read(inode) & (sblk->block_size - 1); + data_ptr = fragment->data + SQUASHFS_I(inode)->u.s1.fragment_offset; + } + + for (i = start_index; i <= end_index && bytes > 0; i++, + bytes -= PAGE_CACHE_SIZE, data_ptr += PAGE_CACHE_SIZE) { + struct page *push_page; + int avail = sparse ? 0 : min_t(unsigned int, bytes, PAGE_CACHE_SIZE); + + TRACE("bytes %d, i %d, available_bytes %d\n", bytes, i, avail); + + push_page = (i == page->index) ? page : + grab_cache_page_nowait(page->mapping, i); + + if (!push_page) + continue; + + if (PageUptodate(push_page)) + goto skip_page; + + pageaddr = kmap_atomic(push_page, KM_USER0); + memcpy(pageaddr, data_ptr, avail); + memset(pageaddr + avail, 0, PAGE_CACHE_SIZE - avail); + kunmap_atomic(pageaddr, KM_USER0); + flush_dcache_page(push_page); + SetPageUptodate(push_page); +skip_page: + unlock_page(push_page); + if(i != page->index) + page_cache_release(push_page); + } + + if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK + || index < file_end) { + if (!sparse) + mutex_unlock(&msblk->read_page_mutex); + kfree(block_list); + } else + release_cached_fragment(msblk, fragment); + + return 0; + +error_out: + SetPageError(page); +out: + pageaddr = kmap_atomic(page, KM_USER0); + memset(pageaddr, 0, PAGE_CACHE_SIZE); + kunmap_atomic(pageaddr, KM_USER0); + flush_dcache_page(page); + if (!PageError(page)) + SetPageUptodate(page); + unlock_page(page); + + kfree(block_list); + return 0; +} + + +static int get_dir_index_using_offset(struct super_block *s, + long long *next_block, unsigned int *next_offset, + long long index_start, unsigned int index_offset, int i_count, + long long f_pos) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + int i, length = 0; + struct squashfs_dir_index index; + + TRACE("Entered get_dir_index_using_offset, i_count %d, f_pos %d\n", + i_count, (unsigned int) f_pos); + + f_pos -= 3; + if (f_pos == 0) + goto finish; + + for (i = 0; i < i_count; i++) { + if (msblk->swap) { + struct squashfs_dir_index sindex; + squashfs_get_cached_block(s, &sindex, index_start, index_offset, + sizeof(sindex), &index_start, &index_offset); + SQUASHFS_SWAP_DIR_INDEX(&index, &sindex); + } else + squashfs_get_cached_block(s, &index, index_start, index_offset, + sizeof(index), &index_start, &index_offset); + + if (index.index > f_pos) + break; + + squashfs_get_cached_block(s, NULL, index_start, index_offset, + index.size + 1, &index_start, &index_offset); + + length = index.index; + *next_block = index.start_block + sblk->directory_table_start; + } + + *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE; + +finish: + return length + 3; +} + + +static int get_dir_index_using_name(struct super_block *s, + long long *next_block, unsigned int *next_offset, + long long index_start, unsigned int index_offset, int i_count, + const char *name, int size) +{ + struct squashfs_sb_info *msblk = s->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + int i, length = 0; + struct squashfs_dir_index *index; + char *str; + + TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count); + + str = kmalloc(sizeof(struct squashfs_dir_index) + + (SQUASHFS_NAME_LEN + 1) * 2, GFP_KERNEL); + if (str == NULL) { + ERROR("Failed to allocate squashfs_dir_index\n"); + goto failure; + } + + index = (struct squashfs_dir_index *) (str + SQUASHFS_NAME_LEN + 1); + strncpy(str, name, size); + str[size] = '\0'; + + for (i = 0; i < i_count; i++) { + if (msblk->swap) { + struct squashfs_dir_index sindex; + squashfs_get_cached_block(s, &sindex, index_start, index_offset, + sizeof(sindex), &index_start, &index_offset); + SQUASHFS_SWAP_DIR_INDEX(index, &sindex); + } else + squashfs_get_cached_block(s, index, index_start, index_offset, + sizeof(struct squashfs_dir_index), &index_start, &index_offset); + + squashfs_get_cached_block(s, index->name, index_start, index_offset, + index->size + 1, &index_start, &index_offset); + + index->name[index->size + 1] = '\0'; + + if (strcmp(index->name, str) > 0) + break; + + length = index->index; + *next_block = index->start_block + sblk->directory_table_start; + } + + *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE; + kfree(str); + +failure: + return length + 3; +} + + +static int squashfs_readdir(struct file *file, void *dirent, filldir_t filldir) +{ + struct inode *i = file->f_dentry->d_inode; + struct squashfs_sb_info *msblk = i->i_sb->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + long long next_block = SQUASHFS_I(i)->start_block + + sblk->directory_table_start; + int next_offset = SQUASHFS_I(i)->offset, length = 0, dir_count; + struct squashfs_dir_header dirh; + struct squashfs_dir_entry *dire; + + TRACE("Entered squashfs_readdir [%llx:%x]\n", next_block, next_offset); + + dire = kmalloc(sizeof(struct squashfs_dir_entry) + + SQUASHFS_NAME_LEN + 1, GFP_KERNEL); + if (dire == NULL) { + ERROR("Failed to allocate squashfs_dir_entry\n"); + goto finish; + } + + while(file->f_pos < 3) { + char *name; + int size, i_ino; + + if(file->f_pos == 0) { + name = "."; + size = 1; + i_ino = i->i_ino; + } else { + name = ".."; + size = 2; + i_ino = SQUASHFS_I(i)->u.s2.parent_inode; + } + TRACE("Calling filldir(%x, %s, %d, %d, %d, %d)\n", + (unsigned int) dirent, name, size, (int) + file->f_pos, i_ino, squashfs_filetype_table[1]); + + if (filldir(dirent, name, size, file->f_pos, i_ino, + squashfs_filetype_table[1]) < 0) { + TRACE("Filldir returned less than 0\n"); + goto finish; + } + file->f_pos += size; + } + + length = get_dir_index_using_offset(i->i_sb, &next_block, &next_offset, + SQUASHFS_I(i)->u.s2.directory_index_start, + SQUASHFS_I(i)->u.s2.directory_index_offset, + SQUASHFS_I(i)->u.s2.directory_index_count, file->f_pos); + + while (length < i_size_read(i)) { + /* read directory header */ + if (msblk->swap) { + struct squashfs_dir_header sdirh; + + if (!squashfs_get_cached_block(i->i_sb, &sdirh, next_block, + next_offset, sizeof(sdirh), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(sdirh); + SQUASHFS_SWAP_DIR_HEADER(&dirh, &sdirh); + } else { + if (!squashfs_get_cached_block(i->i_sb, &dirh, next_block, + next_offset, sizeof(dirh), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(dirh); + } + + dir_count = dirh.count + 1; + while (dir_count--) { + if (msblk->swap) { + struct squashfs_dir_entry sdire; + if (!squashfs_get_cached_block(i->i_sb, &sdire, next_block, + next_offset, sizeof(sdire), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(sdire); + SQUASHFS_SWAP_DIR_ENTRY(dire, &sdire); + } else { + if (!squashfs_get_cached_block(i->i_sb, dire, next_block, + next_offset, sizeof(*dire), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(*dire); + } + + if (!squashfs_get_cached_block(i->i_sb, dire->name, next_block, + next_offset, dire->size + 1, &next_block, &next_offset)) + goto failed_read; + + length += dire->size + 1; + + if (file->f_pos >= length) + continue; + + dire->name[dire->size + 1] = '\0'; + + TRACE("Calling filldir(%x, %s, %d, %d, %x:%x, %d, %d)\n", + (unsigned int) dirent, dire->name, dire->size + 1, + (int) file->f_pos, dirh.start_block, dire->offset, + dirh.inode_number + dire->inode_number, + squashfs_filetype_table[dire->type]); + + if (filldir(dirent, dire->name, dire->size + 1, file->f_pos, + dirh.inode_number + dire->inode_number, + squashfs_filetype_table[dire->type]) < 0) { + TRACE("Filldir returned less than 0\n"); + goto finish; + } + file->f_pos = length; + } + } + +finish: + kfree(dire); + return 0; + +failed_read: + ERROR("Unable to read directory block [%llx:%x]\n", next_block, + next_offset); + kfree(dire); + return 0; +} + + +static struct dentry *squashfs_lookup(struct inode *i, struct dentry *dentry, + struct nameidata *nd) +{ + const unsigned char *name = dentry->d_name.name; + int len = dentry->d_name.len; + struct inode *inode = NULL; + struct squashfs_sb_info *msblk = i->i_sb->s_fs_info; + struct squashfs_super_block *sblk = &msblk->sblk; + long long next_block = SQUASHFS_I(i)->start_block + + sblk->directory_table_start; + int next_offset = SQUASHFS_I(i)->offset, length = 0, dir_count; + struct squashfs_dir_header dirh; + struct squashfs_dir_entry *dire; + + TRACE("Entered squashfs_lookup [%llx:%x]\n", next_block, next_offset); + + dire = kmalloc(sizeof(struct squashfs_dir_entry) + + SQUASHFS_NAME_LEN + 1, GFP_KERNEL); + if (dire == NULL) { + ERROR("Failed to allocate squashfs_dir_entry\n"); + goto exit_lookup; + } + + if (len > SQUASHFS_NAME_LEN) + goto exit_lookup; + + length = get_dir_index_using_name(i->i_sb, &next_block, &next_offset, + SQUASHFS_I(i)->u.s2.directory_index_start, + SQUASHFS_I(i)->u.s2.directory_index_offset, + SQUASHFS_I(i)->u.s2.directory_index_count, name, len); + + while (length < i_size_read(i)) { + /* read directory header */ + if (msblk->swap) { + struct squashfs_dir_header sdirh; + if (!squashfs_get_cached_block(i->i_sb, &sdirh, next_block, + next_offset, sizeof(sdirh), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(sdirh); + SQUASHFS_SWAP_DIR_HEADER(&dirh, &sdirh); + } else { + if (!squashfs_get_cached_block(i->i_sb, &dirh, next_block, + next_offset, sizeof(dirh), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(dirh); + } + + dir_count = dirh.count + 1; + while (dir_count--) { + if (msblk->swap) { + struct squashfs_dir_entry sdire; + if (!squashfs_get_cached_block(i->i_sb, &sdire, next_block, + next_offset, sizeof(sdire), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(sdire); + SQUASHFS_SWAP_DIR_ENTRY(dire, &sdire); + } else { + if (!squashfs_get_cached_block(i->i_sb, dire, next_block, + next_offset, sizeof(*dire), &next_block, &next_offset)) + goto failed_read; + + length += sizeof(*dire); + } + + if (!squashfs_get_cached_block(i->i_sb, dire->name, next_block, + next_offset, dire->size + 1, &next_block, &next_offset)) + goto failed_read; + + length += dire->size + 1; + + if (name[0] < dire->name[0]) + goto exit_lookup; + + if ((len == dire->size + 1) && !strncmp(name, dire->name, len)) { + squashfs_inode_t ino = SQUASHFS_MKINODE(dirh.start_block, + dire->offset); + + TRACE("calling squashfs_iget for directory entry %s, inode" + " %x:%x, %d\n", name, dirh.start_block, dire->offset, + dirh.inode_number + dire->inode_number); + + inode = squashfs_iget(i->i_sb, ino, dirh.inode_number + dire->inode_number); + + goto exit_lookup; + } + } + } + +exit_lookup: + kfree(dire); + if (inode) + return d_splice_alias(inode, dentry); + d_add(dentry, inode); + return ERR_PTR(0); + +failed_read: + ERROR("Unable to read directory block [%llx:%x]\n", next_block, + next_offset); + goto exit_lookup; +} + + +static int squashfs_remount(struct super_block *s, int *flags, char *data) +{ + *flags |= MS_RDONLY; + return 0; +} + + +static void squashfs_put_super(struct super_block *s) +{ + if (s->s_fs_info) { + struct squashfs_sb_info *sbi = s->s_fs_info; + squashfs_cache_delete(sbi->block_cache); + squashfs_cache_delete(sbi->fragment_cache); + vfree(sbi->read_page); + kfree(sbi->uid); + kfree(sbi->fragment_index); + kfree(sbi->fragment_index_2); + kfree(sbi->meta_index); + vfree(sbi->stream.workspace); + kfree(s->s_fs_info); + s->s_fs_info = NULL; + } +} + + +static int squashfs_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data, struct vfsmount *mnt) +{ + return get_sb_bdev(fs_type, flags, dev_name, data, squashfs_fill_super, + mnt); +} + + +static int __init init_squashfs_fs(void) +{ + int err = init_inodecache(); + if (err) + goto out; + + printk(KERN_INFO "squashfs: version 3.4 (2008/08/26) " + "Phillip Lougher\n"); + + err = register_filesystem(&squashfs_fs_type); + if (err) + destroy_inodecache(); + +out: + return err; +} + + +static void __exit exit_squashfs_fs(void) +{ + unregister_filesystem(&squashfs_fs_type); + destroy_inodecache(); +} + + +static struct kmem_cache * squashfs_inode_cachep; + + +static struct inode *squashfs_alloc_inode(struct super_block *sb) +{ + struct squashfs_inode_info *ei; + ei = kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL); + return ei ? &ei->vfs_inode : NULL; +} + + +static void squashfs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(squashfs_inode_cachep, SQUASHFS_I(inode)); +} + + +static void init_once(void *foo) +{ + struct squashfs_inode_info *ei = foo; + + inode_init_once(&ei->vfs_inode); +} + + +static int __init init_inodecache(void) +{ + squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache", + sizeof(struct squashfs_inode_info), 0, + SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT, init_once); + if (squashfs_inode_cachep == NULL) + return -ENOMEM; + return 0; +} + + +static void destroy_inodecache(void) +{ + kmem_cache_destroy(squashfs_inode_cachep); +} + + +module_init(init_squashfs_fs); +module_exit(exit_squashfs_fs); +MODULE_DESCRIPTION("squashfs 3.4, a compressed read-only filesystem"); +MODULE_AUTHOR("Phillip Lougher <phillip@lougher.demon.co.uk>"); +MODULE_LICENSE("GPL"); |