diff options
Diffstat (limited to 'fs/squashfs')
| -rw-r--r-- | fs/squashfs/sqfs.c | 54 |
1 files changed, 35 insertions, 19 deletions
diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c index 5de69ac..dca13bd 100644 --- a/fs/squashfs/sqfs.c +++ b/fs/squashfs/sqfs.c @@ -1310,7 +1310,7 @@ int sqfs_read(const char *filename, void *buf, loff_t offset, loff_t len, { char *dir = NULL, *fragment_block, *datablock = NULL, *data_buffer = NULL; char *fragment = NULL, *file = NULL, *resolved, *data; - u64 start, n_blks, table_size, data_offset, table_offset; + u64 start, n_blks, table_size, data_offset, table_offset, sparse_size; int ret, j, i_number, datablk_count = 0; struct squashfs_super_block *sblk = ctxt.sblk; struct squashfs_fragment_block_entry frag_entry; @@ -1444,28 +1444,43 @@ int sqfs_read(const char *filename, void *buf, loff_t offset, loff_t len, n_blks = DIV_ROUND_UP(table_size + table_offset, ctxt.cur_dev->blksz); - data_buffer = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz); + /* Don't load any data for sparse blocks */ + if (finfo.blk_sizes[j] == 0) { + n_blks = 0; + table_offset = 0; + data_buffer = NULL; + data = NULL; + } else { + data_buffer = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz); - if (!data_buffer) { - ret = -ENOMEM; - goto out; - } + if (!data_buffer) { + ret = -ENOMEM; + goto out; + } - ret = sqfs_disk_read(start, n_blks, data_buffer); - if (ret < 0) { - /* - * Possible causes: too many data blocks or too large - * SquashFS block size. Tip: re-compile the SquashFS - * image with mksquashfs's -b <block_size> option. - */ - printf("Error: too many data blocks to be read.\n"); - goto out; - } + ret = sqfs_disk_read(start, n_blks, data_buffer); + if (ret < 0) { + /* + * Possible causes: too many data blocks or too large + * SquashFS block size. Tip: re-compile the SquashFS + * image with mksquashfs's -b <block_size> option. + */ + printf("Error: too many data blocks to be read.\n"); + goto out; + } - data = data_buffer + table_offset; + data = data_buffer + table_offset; + } /* Load the data */ - if (SQFS_COMPRESSED_BLOCK(finfo.blk_sizes[j])) { + if (finfo.blk_sizes[j] == 0) { + /* This is a sparse block */ + sparse_size = get_unaligned_le32(&sblk->block_size); + if ((*actread + sparse_size) > len) + sparse_size = len - *actread; + memset(buf + *actread, 0, sparse_size); + *actread += sparse_size; + } else if (SQFS_COMPRESSED_BLOCK(finfo.blk_sizes[j])) { dest_len = get_unaligned_le32(&sblk->block_size); ret = sqfs_decompress(&ctxt, datablock, &dest_len, data, table_size); @@ -1484,7 +1499,8 @@ int sqfs_read(const char *filename, void *buf, loff_t offset, loff_t len, } data_offset += table_size; - free(data_buffer); + if (data_buffer) + free(data_buffer); data_buffer = NULL; if (*actread >= len) break; |