/* * Squashfs - a compressed read only filesystem for Linux * * Copyright (c) 2002, 2003, 2004, 2005, 2006 * Phillip Lougher * * LZMA decompressor support added by Oleg I. Vdovikin * Copyright (c) 2005 Oleg I.Vdovikin * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "squashfs.h" #ifdef CONFIG_LZMA_FS_INFLATE #define SQUASHFS_LZMA #endif #ifdef SQUASHFS_LZMA #include "LzmaDecode.h" /* default LZMA settings, should be in sync with mksquashfs */ #define LZMA_LC 3 #define LZMA_LP 0 #define LZMA_PB 2 #define LZMA_WORKSPACE_SIZE ((LZMA_BASE_SIZE + \ (LZMA_LIT_SIZE << (LZMA_LC + LZMA_LP))) * sizeof(CProb)) #endif static struct super_block *squashfs_read_super(struct super_block *, void *, int); static void squashfs_put_super(struct super_block *); static int squashfs_statfs(struct super_block *, struct statfs *); static int squashfs_symlink_readpage(struct file *file, struct page *page); static int squashfs_readpage(struct file *file, struct page *page); static int squashfs_readpage4K(struct file *file, struct page *page); static int squashfs_readdir(struct file *, void *, filldir_t); static struct dentry *squashfs_lookup(struct inode *, struct dentry *); static struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode); static long long read_blocklist(struct inode *inode, int index, int readahead_blks, char *block_list, unsigned short **block_p, unsigned int *bsize); #ifdef SQUASHFS_LZMA static unsigned char lzma_workspace[LZMA_WORKSPACE_SIZE]; #else static z_stream stream; #endif static DECLARE_FSTYPE_DEV(squashfs_fs_type, "squashfs", squashfs_read_super); static 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_ops = { .statfs = squashfs_statfs, .put_super = squashfs_put_super, }; SQSH_EXTERN struct address_space_operations squashfs_symlink_aops = { .readpage = squashfs_symlink_readpage }; SQSH_EXTERN struct address_space_operations squashfs_aops = { .readpage = squashfs_readpage }; SQSH_EXTERN struct address_space_operations squashfs_aops_4K = { .readpage = squashfs_readpage4K }; static struct file_operations squashfs_dir_ops = { .read = generic_read_dir, .readdir = squashfs_readdir }; static 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->u.squashfs_sb; 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) { struct squashfs_sb_info *msblk = &s->u.squashfs_sb; struct buffer_head *bh[((SQUASHFS_FILE_MAX_SIZE - 1) >> msblk->devblksize_log2) + 2]; unsigned int offset = index & ((1 << msblk->devblksize_log2) - 1); unsigned int cur_index = index >> msblk->devblksize_log2; int bytes, avail_bytes, b = 0, k; char *c_buffer; unsigned int compressed; unsigned int c_byte = length; if (c_byte) { bytes = msblk->devblksize - offset; compressed = SQUASHFS_COMPRESSED_BLOCK(c_byte); c_buffer = compressed ? msblk->read_data : buffer; c_byte = SQUASHFS_COMPRESSED_SIZE_BLOCK(c_byte); TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed ? "" : "un", (unsigned int) c_byte); if (!(bh[0] = sb_getblk(s, cur_index))) goto block_release; for (b = 1; bytes < c_byte; b++) { if (!(bh[b] = sb_getblk(s, ++cur_index))) goto block_release; bytes += msblk->devblksize; } ll_rw_block(READ, b, bh); } else { if (!(bh[0] = get_block_length(s, &cur_index, &offset, &c_byte))) goto read_failure; bytes = msblk->devblksize - offset; compressed = SQUASHFS_COMPRESSED(c_byte); c_buffer = compressed ? msblk->read_data : buffer; c_byte = SQUASHFS_COMPRESSED_SIZE(c_byte); TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed ? "" : "un", (unsigned int) c_byte); for (b = 1; bytes < c_byte; b++) { if (!(bh[b] = sb_getblk(s, ++cur_index))) goto block_release; bytes += msblk->devblksize; } ll_rw_block(READ, b - 1, bh + 1); } if (compressed) down(&msblk->read_data_mutex); for (bytes = 0, k = 0; k < b; k++) { avail_bytes = (c_byte - bytes) > (msblk->devblksize - offset) ? msblk->devblksize - offset : c_byte - bytes; wait_on_buffer(bh[k]); if (!buffer_uptodate(bh[k])) goto block_release; memcpy(c_buffer + bytes, bh[k]->b_data + offset, avail_bytes); bytes += avail_bytes; offset = 0; brelse(bh[k]); } /* * uncompress block */ if (compressed) { int zlib_err; #ifdef SQUASHFS_LZMA if ((zlib_err = LzmaDecode(lzma_workspace, LZMA_WORKSPACE_SIZE, LZMA_LC, LZMA_LP, LZMA_PB, c_buffer, c_byte, buffer, msblk->read_size, &bytes)) != LZMA_RESULT_OK) { ERROR("lzma returned unexpected result 0x%x\n", zlib_err); bytes = 0; } #else stream.next_in = c_buffer; stream.avail_in = c_byte; stream.next_out = buffer; stream.avail_out = msblk->read_size; if (((zlib_err = zlib_inflateInit(&stream)) != Z_OK) || ((zlib_err = zlib_inflate(&stream, Z_FINISH)) != Z_STREAM_END) || ((zlib_err = zlib_inflateEnd(&stream)) != Z_OK)) { ERROR("zlib_fs returned unexpected result 0x%x\n", zlib_err); bytes = 0; } else bytes = stream.total_out; #endif up(&msblk->read_data_mutex); } if (next_index) *next_index = index + c_byte + (length ? 0 : (SQUASHFS_CHECK_DATA(msblk->sblk.flags) ? 3 : 2)); return bytes; block_release: while (--b >= 0) brelse(bh[b]); read_failure: ERROR("sb_bread failed reading block 0x%x\n", cur_index); return 0; } SQSH_EXTERN int squashfs_get_cached_block(struct super_block *s, char *buffer, long long block, unsigned int offset, int length, long long *next_block, unsigned int *next_offset) { struct squashfs_sb_info *msblk = &s->u.squashfs_sb; int n, i, bytes, return_length = length; long long next_index; TRACE("Entered squashfs_get_cached_block [%llx:%x]\n", block, offset); while ( 1 ) { for (i = 0; i < SQUASHFS_CACHED_BLKS; i++) if (msblk->block_cache[i].block == block) break; down(&msblk->block_cache_mutex); if (i == SQUASHFS_CACHED_BLKS) { /* read inode header block */ for (i = msblk->next_cache, n = SQUASHFS_CACHED_BLKS; n ; n --, i = (i + 1) % SQUASHFS_CACHED_BLKS) if (msblk->block_cache[i].block != SQUASHFS_USED_BLK) break; if (n == 0) { wait_queue_t wait; init_waitqueue_entry(&wait, current); add_wait_queue(&msblk->waitq, &wait); set_current_state(TASK_UNINTERRUPTIBLE); up(&msblk->block_cache_mutex); schedule(); set_current_state(TASK_RUNNING); remove_wait_queue(&msblk->waitq, &wait); continue; } msblk->next_cache = (i + 1) % SQUASHFS_CACHED_BLKS; if (msblk->block_cache[i].block == SQUASHFS_INVALID_BLK) { if (!(msblk->block_cache[i].data = kmalloc(SQUASHFS_METADATA_SIZE, GFP_KERNEL))) { ERROR("Failed to allocate cache" "block\n"); up(&msblk->block_cache_mutex); goto out; } } msblk->block_cache[i].block = SQUASHFS_USED_BLK; up(&msblk->block_cache_mutex); if (!(msblk->block_cache[i].length = squashfs_read_data(s, msblk->block_cache[i].data, block, 0, &next_index))) { ERROR("Unable to read cache block [%llx:%x]\n", block, offset); goto out; } down(&msblk->block_cache_mutex); wake_up(&msblk->waitq); msblk->block_cache[i].block = block; msblk->block_cache[i].next_index = next_index; TRACE("Read cache block [%llx:%x]\n", block, offset); } if (msblk->block_cache[i].block != block) { up(&msblk->block_cache_mutex); continue; } if ((bytes = msblk->block_cache[i].length - offset) >= length) { if (buffer) memcpy(buffer, msblk->block_cache[i].data + offset, length); if (msblk->block_cache[i].length - offset == length) { *next_block = msblk->block_cache[i].next_index; *next_offset = 0; } else { *next_block = block; *next_offset = offset + length; } up(&msblk->block_cache_mutex); goto finish; } else { if (buffer) { memcpy(buffer, msblk->block_cache[i].data + offset, bytes); buffer += bytes; } block = msblk->block_cache[i].next_index; up(&msblk->block_cache_mutex); length -= bytes; offset = 0; } } finish: return return_length; out: return 0; } 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->u.squashfs_sb; 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, (char *) &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, (char *) &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_fragment_cache *fragment) { down(&msblk->fragment_mutex); fragment->locked --; wake_up(&msblk->fragment_wait_queue); up(&msblk->fragment_mutex); } SQSH_EXTERN struct squashfs_fragment_cache *get_cached_fragment(struct super_block *s, long long start_block, int length) { int i, n; struct squashfs_sb_info *msblk = &s->u.squashfs_sb; while ( 1 ) { down(&msblk->fragment_mutex); for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS && msblk->fragment[i].block != start_block; i++); if (i == SQUASHFS_CACHED_FRAGMENTS) { for (i = msblk->next_fragment, n = SQUASHFS_CACHED_FRAGMENTS; n && msblk->fragment[i].locked; n--, i = (i + 1) % SQUASHFS_CACHED_FRAGMENTS); if (n == 0) { wait_queue_t wait; init_waitqueue_entry(&wait, current); add_wait_queue(&msblk->fragment_wait_queue, &wait); set_current_state(TASK_UNINTERRUPTIBLE); up(&msblk->fragment_mutex); schedule(); set_current_state(TASK_RUNNING); remove_wait_queue(&msblk->fragment_wait_queue, &wait); continue; } msblk->next_fragment = (msblk->next_fragment + 1) % SQUASHFS_CACHED_FRAGMENTS; if (msblk->fragment[i].data == NULL) if (!(msblk->fragment[i].data = SQUASHFS_ALLOC (SQUASHFS_FILE_MAX_SIZE))) { ERROR("Failed to allocate fragment " "cache block\n"); up(&msblk->fragment_mutex); goto out; } msblk->fragment[i].block = SQUASHFS_INVALID_BLK; msblk->fragment[i].locked = 1; up(&msblk->fragment_mutex); if (!(msblk->fragment[i].length = squashfs_read_data(s, msblk->fragment[i].data, start_block, length, NULL))) { ERROR("Unable to read fragment cache block " "[%llx]\n", start_block); msblk->fragment[i].locked = 0; goto out; } msblk->fragment[i].block = start_block; TRACE("New fragment %d, start block %lld, locked %d\n", i, msblk->fragment[i].block, msblk->fragment[i].locked); break; } msblk->fragment[i].locked++; up(&msblk->fragment_mutex); TRACE("Got fragment %d, start block %lld, locked %d\n", i, msblk->fragment[i].block, msblk->fragment[i].locked); break; } return &msblk->fragment[i]; out: return NULL; } static struct inode *squashfs_new_inode(struct super_block *s, struct squashfs_base_inode_header *inodeb) { struct squashfs_sb_info *msblk = &s->u.squashfs_sb; struct inode *i = new_inode(s); if (i) { i->i_ino = inodeb->inode_number; i->i_mtime = inodeb->mtime; i->i_atime = inodeb->mtime; i->i_ctime = 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]; } return i; } static struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode) { struct inode *i; struct squashfs_sb_info *msblk = &s->u.squashfs_sb; 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_iget\n"); if (msblk->swap) { if (!squashfs_get_cached_block(s, (char *) 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, (char *) inodeb, block, offset, sizeof(*inodeb), &next_block, &next_offset)) goto failed_read; 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; frag_blk = SQUASHFS_INVALID_BLK; if (inodep->fragment != SQUASHFS_INVALID_FRAG && !get_fragment_location(s, inodep->fragment, &frag_blk, &frag_size)) goto failed_read; if((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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; i->i_blksize = PAGE_CACHE_SIZE; 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; if (sblk->block_size > 4096) i->i_data.a_ops = &squashfs_aops; else i->i_data.a_ops = &squashfs_aops_4K; 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; frag_blk = SQUASHFS_INVALID_BLK; if (inodep->fragment != SQUASHFS_INVALID_FRAG && !get_fragment_location(s, inodep->fragment, &frag_blk, &frag_size)) goto failed_read; if((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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; i->i_blksize = PAGE_CACHE_SIZE; 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; if (sblk->block_size > 4096) i->i_data.a_ops = &squashfs_aops; else i->i_data.a_ops = &squashfs_aops_4K; 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; if((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; if((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; if((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; if ((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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, 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, (char *) 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, (char *) inodep, block, offset, sizeof(*inodep), &next_block, &next_offset)) goto failed_read; if ((i = squashfs_new_inode(s, inodeb)) == NULL) goto failed_read1; 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; } insert_inode_hash(i); return i; failed_read: ERROR("Unable to read inode [%llx:%x]\n", block, offset); failed_read1: return NULL; } int read_fragment_index_table(struct super_block *s) { struct squashfs_sb_info *msblk = &s->u.squashfs_sb; struct squashfs_super_block *sblk = &msblk->sblk; if (!(msblk->fragment_index = kmalloc(SQUASHFS_FRAGMENT_INDEX_BYTES (sblk->fragments), GFP_KERNEL))) { ERROR("Failed to allocate uid/gid table\n"); return 0; } if (SQUASHFS_FRAGMENT_INDEX_BYTES(sblk->fragments) && !squashfs_read_data(s, (char *) msblk->fragment_index, sblk->fragment_table_start, SQUASHFS_FRAGMENT_INDEX_BYTES (sblk->fragments) | SQUASHFS_COMPRESSED_BIT_BLOCK, NULL)) { 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++) { 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->iget = squashfs_iget; 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 struct super_block *squashfs_read_super(struct super_block *s, void *data, int silent) { kdev_t dev = s->s_dev; struct squashfs_sb_info *msblk = &s->u.squashfs_sb; struct squashfs_super_block *sblk = &msblk->sblk; int i; struct inode *root; msblk->devblksize = get_hardsect_size(dev); if(msblk->devblksize < BLOCK_SIZE) msblk->devblksize = BLOCK_SIZE; msblk->devblksize_log2 = ffz(~msblk->devblksize); set_blocksize(dev, msblk->devblksize); s->s_blocksize = msblk->devblksize; s->s_blocksize_bits = msblk->devblksize_log2; init_MUTEX(&msblk->read_data_mutex); init_MUTEX(&msblk->read_page_mutex); init_MUTEX(&msblk->block_cache_mutex); init_MUTEX(&msblk->fragment_mutex); init_waitqueue_head(&msblk->waitq); init_waitqueue_head(&msblk->fragment_wait_queue); if (!squashfs_read_data(s, (char *) sblk, SQUASHFS_START, sizeof(struct squashfs_super_block) | SQUASHFS_COMPRESSED_BIT_BLOCK, NULL)) { SERROR("unable to read superblock\n"); goto failed_mount; } /* Check it is a SQUASHFS superblock */ msblk->swap = 0; 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(dev)); 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(dev)); goto failed_mount; } } /* Check the MAJOR & MINOR versions */ if(!supported_squashfs_filesystem(msblk, silent)) goto failed_mount; TRACE("Found valid superblock on %s\n", bdevname(dev)); 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 %s present 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_flags |= MS_RDONLY; s->s_op = &squashfs_ops; /* Init inode_table block pointer array */ if (!(msblk->block_cache = kmalloc(sizeof(struct squashfs_cache) * SQUASHFS_CACHED_BLKS, GFP_KERNEL))) { ERROR("Failed to allocate block cache\n"); goto failed_mount; } for (i = 0; i < SQUASHFS_CACHED_BLKS; i++) msblk->block_cache[i].block = SQUASHFS_INVALID_BLK; msblk->next_cache = 0; /* Allocate read_data block */ msblk->read_size = (sblk->block_size < SQUASHFS_METADATA_SIZE) ? SQUASHFS_METADATA_SIZE : sblk->block_size; if (!(msblk->read_data = kmalloc(msblk->read_size, GFP_KERNEL))) { ERROR("Failed to allocate read_data block\n"); goto failed_mount; } /* Allocate read_page block */ if (!(msblk->read_page = kmalloc(sblk->block_size, GFP_KERNEL))) { ERROR("Failed to allocate read_page block\n"); goto failed_mount; } /* Allocate uid and gid tables */ if (!(msblk->uid = kmalloc((sblk->no_uids + sblk->no_guids) * sizeof(unsigned int), GFP_KERNEL))) { 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)) { 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)) { ERROR("unable to read uid/gid table\n"); goto failed_mount; } if (sblk->s_major == 1 && squashfs_1_0_supported(msblk)) goto allocate_root; if (!(msblk->fragment = kmalloc(sizeof(struct squashfs_fragment_cache) * SQUASHFS_CACHED_FRAGMENTS, GFP_KERNEL))) { ERROR("Failed to allocate fragment block cache\n"); goto failed_mount; } for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS; i++) { msblk->fragment[i].locked = 0; msblk->fragment[i].block = SQUASHFS_INVALID_BLK; msblk->fragment[i].data = NULL; } msblk->next_fragment = 0; /* Allocate fragment index table */ if(msblk->read_fragment_index_table(s) == 0) goto failed_mount; allocate_root: if ((root = (msblk->iget)(s, sblk->root_inode)) == NULL) goto failed_mount; if ((s->s_root = d_alloc_root(root)) == NULL) { ERROR("Root inode create failed\n"); iput(root); goto failed_mount; } TRACE("Leaving squashfs_read_super\n"); return s; failed_mount: kfree(msblk->fragment_index); kfree(msblk->fragment); kfree(msblk->uid); kfree(msblk->read_page); kfree(msblk->read_data); kfree(msblk->block_cache); kfree(msblk->fragment_index_2); return NULL; } static int squashfs_statfs(struct super_block *s, struct statfs *buf) { struct squashfs_sb_info *msblk = &s->u.squashfs_sb; 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; 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) { if (!(bytes = squashfs_get_cached_block(inode->i_sb, NULL, block, offset, PAGE_CACHE_SIZE, &block, &offset))) { 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; } bytes = (i_size_read(inode) - length) > PAGE_CACHE_SIZE ? PAGE_CACHE_SIZE : i_size_read(inode) - length; if (!(bytes = squashfs_get_cached_block(inode->i_sb, pageaddr, block, offset, bytes, &block, &offset))) ERROR("Unable to read symbolic link [%llx:%x]\n", block, offset); skip_read: memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes); kunmap(page); SetPageUptodate(page); UnlockPage(page); return 0; } 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->u.squashfs_sb; int i; down(&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: up(&msblk->meta_index_mutex); return meta; } struct meta_index *empty_meta_index(struct inode *inode, int offset, int skip) { struct squashfs_sb_info *msblk = &inode->i_sb->u.squashfs_sb; struct meta_index *meta = NULL; int i; down(&msblk->meta_index_mutex); TRACE("empty_meta_index: offset %d, skip %d\n", offset, skip); if(msblk->meta_index == NULL) { if (!(msblk->meta_index = kmalloc(sizeof(struct meta_index) * SQUASHFS_META_NUMBER, GFP_KERNEL))) { 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: up(&msblk->meta_index_mutex); return meta; } void release_meta_index(struct inode *inode, struct meta_index *meta) { meta->locked = 0; } 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->u.squashfs_sb; 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("Unable to read 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("Unable to read 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->u.squashfs_sb; 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) { if ((meta = empty_meta_index(inode, offset + 1, skip)) == NULL) goto all_done; } else { offset = index < meta->offset + meta->entries ? index : meta->offset + meta->entries - 1; 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->u.squashfs_sb; struct squashfs_super_block *sblk = &msblk->sblk; unsigned char block_list[SIZE]; long long block; unsigned int bsize, i = 0, bytes = 0, byte_offset = 0; int index = page->index >> (sblk->block_log - PAGE_CACHE_SHIFT); void *pageaddr; struct squashfs_fragment_cache *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; 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 skip_read; if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK || index < (i_size_read(inode) >> sblk->block_log)) { if ((block = (msblk->read_blocklist)(inode, index, 1, block_list, NULL, &bsize)) == 0) goto skip_read; down(&msblk->read_page_mutex); if (!(bytes = squashfs_read_data(inode->i_sb, msblk->read_page, block, bsize, NULL))) { ERROR("Unable to read page, block %llx, size %x\n", block, bsize); up(&msblk->read_page_mutex); goto skip_read; } } else { if ((fragment = get_cached_fragment(inode->i_sb, SQUASHFS_I(inode)-> u.s1.fragment_start_block, SQUASHFS_I(inode)->u.s1.fragment_size)) == NULL) { 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); goto skip_read; } bytes = SQUASHFS_I(inode)->u.s1.fragment_offset + (i_size_read(inode) & (sblk->block_size - 1)); byte_offset = SQUASHFS_I(inode)->u.s1.fragment_offset; data_ptr = fragment->data; } for (i = start_index; i <= end_index && byte_offset < bytes; i++, byte_offset += PAGE_CACHE_SIZE) { struct page *push_page; int available_bytes = (bytes - byte_offset) > PAGE_CACHE_SIZE ? PAGE_CACHE_SIZE : bytes - byte_offset; TRACE("bytes %d, i %d, byte_offset %d, available_bytes %d\n", bytes, i, byte_offset, available_bytes); if (i == page->index) { pageaddr = kmap_atomic(page, KM_USER0); memcpy(pageaddr, data_ptr + byte_offset, available_bytes); memset(pageaddr + available_bytes, 0, PAGE_CACHE_SIZE - available_bytes); kunmap_atomic(pageaddr, KM_USER0); flush_dcache_page(page); SetPageUptodate(page); UnlockPage(page); } else if ((push_page = grab_cache_page_nowait(page->mapping, i))) { pageaddr = kmap_atomic(push_page, KM_USER0); memcpy(pageaddr, data_ptr + byte_offset, available_bytes); memset(pageaddr + available_bytes, 0, PAGE_CACHE_SIZE - available_bytes); kunmap_atomic(pageaddr, KM_USER0); flush_dcache_page(push_page); SetPageUptodate(push_page); UnlockPage(push_page); page_cache_release(push_page); } } if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK || index < (i_size_read(inode) >> sblk->block_log)) up(&msblk->read_page_mutex); else release_cached_fragment(msblk, fragment); return 0; skip_read: pageaddr = kmap_atomic(page, KM_USER0); memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes); kunmap_atomic(pageaddr, KM_USER0); flush_dcache_page(page); SetPageUptodate(page); UnlockPage(page); return 0; } static int squashfs_readpage4K(struct file *file, struct page *page) { struct inode *inode = page->mapping->host; struct squashfs_sb_info *msblk = &inode->i_sb->u.squashfs_sb; struct squashfs_super_block *sblk = &msblk->sblk; unsigned char block_list[SIZE]; long long block; unsigned int bsize, bytes = 0; void *pageaddr; TRACE("Entered squashfs_readpage4K, 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)) { pageaddr = kmap_atomic(page, KM_USER0); goto skip_read; } if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK || page->index < (i_size_read(inode) >> sblk->block_log)) { block = (msblk->read_blocklist)(inode, page->index, 1, block_list, NULL, &bsize); down(&msblk->read_page_mutex); bytes = squashfs_read_data(inode->i_sb, msblk->read_page, block, bsize, NULL); pageaddr = kmap_atomic(page, KM_USER0); if (bytes) memcpy(pageaddr, msblk->read_page, bytes); else ERROR("Unable to read page, block %llx, size %x\n", block, bsize); up(&msblk->read_page_mutex); } else { struct squashfs_fragment_cache *fragment = get_cached_fragment(inode->i_sb, SQUASHFS_I(inode)-> u.s1.fragment_start_block, SQUASHFS_I(inode)-> u.s1.fragment_size); pageaddr = kmap_atomic(page, KM_USER0); if (fragment) { bytes = i_size_read(inode) & (sblk->block_size - 1); memcpy(pageaddr, fragment->data + SQUASHFS_I(inode)-> u.s1.fragment_offset, bytes); release_cached_fragment(msblk, fragment); } else 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); } skip_read: memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes); kunmap_atomic(pageaddr, KM_USER0); flush_dcache_page(page); SetPageUptodate(page); UnlockPage(page); 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->u.squashfs_sb; 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, (char *) &sindex, index_start, index_offset, sizeof(sindex), &index_start, &index_offset); SQUASHFS_SWAP_DIR_INDEX(&index, &sindex); } else squashfs_get_cached_block(s, (char *) &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->u.squashfs_sb; struct squashfs_super_block *sblk = &msblk->sblk; int i, length = 0; char buffer[sizeof(struct squashfs_dir_index) + SQUASHFS_NAME_LEN + 1]; struct squashfs_dir_index *index = (struct squashfs_dir_index *) buffer; char str[SQUASHFS_NAME_LEN + 1]; TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count); 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, (char *) &sindex, index_start, index_offset, sizeof(sindex), &index_start, &index_offset); SQUASHFS_SWAP_DIR_INDEX(index, &sindex); } else squashfs_get_cached_block(s, (char *) 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; 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->u.squashfs_sb; 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, dirs_read = 0, dir_count; struct squashfs_dir_header dirh; char buffer[sizeof(struct squashfs_dir_entry) + SQUASHFS_NAME_LEN + 1]; struct squashfs_dir_entry *dire = (struct squashfs_dir_entry *) buffer; TRACE("Entered squashfs_readdir [%llx:%x]\n", next_block, next_offset); 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; dirs_read++; } 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, (char *) &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, (char *) &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, (char *) &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, (char *) 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; dirs_read++; } } finish: return dirs_read; failed_read: ERROR("Unable to read directory block [%llx:%x]\n", next_block, next_offset); return 0; } static struct dentry *squashfs_lookup(struct inode *i, struct dentry *dentry) { 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->u.squashfs_sb; 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; char buffer[sizeof(struct squashfs_dir_entry) + SQUASHFS_NAME_LEN]; struct squashfs_dir_entry *dire = (struct squashfs_dir_entry *) buffer; TRACE("Entered squashfs_lookup [%llx:%x]\n", next_block, next_offset); if (len > SQUASHFS_NAME_LEN) goto exit_loop; 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, (char *) &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, (char *) &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, (char *) &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, (char *) 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_loop; 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 = (msblk->iget)(i->i_sb, ino); goto exit_loop; } } } exit_loop: 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_loop; } static void squashfs_put_super(struct super_block *s) { int i; struct squashfs_sb_info *sbi = &s->u.squashfs_sb; if (sbi->block_cache) for (i = 0; i < SQUASHFS_CACHED_BLKS; i++) if (sbi->block_cache[i].block != SQUASHFS_INVALID_BLK) kfree(sbi->block_cache[i].data); if (sbi->fragment) for (i = 0; i < SQUASHFS_CACHED_FRAGMENTS; i++) SQUASHFS_FREE(sbi->fragment[i].data); kfree(sbi->fragment); kfree(sbi->block_cache); kfree(sbi->read_data); kfree(sbi->read_page); kfree(sbi->uid); kfree(sbi->fragment_index); kfree(sbi->fragment_index_2); sbi->block_cache = NULL; sbi->uid = NULL; sbi->read_data = NULL; sbi->read_page = NULL; sbi->fragment = NULL; sbi->fragment_index = NULL; sbi->fragment_index_2 = NULL; } static int __init init_squashfs_fs(void) { printk(KERN_INFO "squashfs: version 3.0 (2006/03/15) " "Phillip Lougher\n"); #ifndef SQUASHFS_LZMA if (!(stream.workspace = vmalloc(zlib_inflate_workspacesize()))) { ERROR("Failed to allocate zlib workspace\n"); return -ENOMEM; } #endif return register_filesystem(&squashfs_fs_type); } static void __exit exit_squashfs_fs(void) { #ifndef SQUASHFS_LZMA vfree(stream.workspace); #endif unregister_filesystem(&squashfs_fs_type); } EXPORT_NO_SYMBOLS; module_init(init_squashfs_fs); module_exit(exit_squashfs_fs); MODULE_DESCRIPTION("squashfs, a compressed read-only filesystem"); MODULE_AUTHOR("Phillip Lougher "); MODULE_LICENSE("GPL");