diff options
| author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2024-09-12 15:41:56 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2024-09-12 23:00:09 +0800 |
| commit | 7c3ca1838a7831855cbf2e6927a10e0e4723edf6 (patch) | |
| tree | ecdcfadd129552f99178ced9ef11a890bdaa63c3 /fs | |
| parent | 79f504a2cd3c0b7d953d0015618a2a41559a2cfd (diff) | |
erofs: restrict pcluster size limitations
Error out if {en,de}encoded size of a pcluster is unsupported:
Maximum supported encoded size (of a pcluster): 1 MiB
Maximum supported decoded size (of a pcluster): 12 MiB
Users can still choose to use supported large configurations (e.g.,
for archival purposes), but there may be performance penalties in
low-memory scenarios compared to smaller pclusters.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240912074156.2925394-1-hsiangkao@linux.alibaba.com
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/erofs/erofs_fs.h | 5 | ||||
| -rw-r--r-- | fs/erofs/zmap.c | 42 |
2 files changed, 24 insertions, 23 deletions
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index 6c0c270c42e1..c8f2ae845bd2 100644 --- a/fs/erofs/erofs_fs.h +++ b/fs/erofs/erofs_fs.h @@ -288,9 +288,12 @@ struct erofs_dirent { #define EROFS_NAME_LEN 255 -/* maximum supported size of a physical compression cluster */ +/* maximum supported encoded size of a physical compressed cluster */ #define Z_EROFS_PCLUSTER_MAX_SIZE (1024 * 1024) +/* maximum supported decoded size of a physical compressed cluster */ +#define Z_EROFS_PCLUSTER_MAX_DSIZE (12 * 1024 * 1024) + /* available compression algorithm types (for h_algorithmtype) */ enum { Z_EROFS_COMPRESSION_LZ4 = 0, diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index 403af6e31d5b..e980e29873a5 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -687,32 +687,30 @@ int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, int err = 0; trace_erofs_map_blocks_enter(inode, map, flags); - - /* when trying to read beyond EOF, leave it unmapped */ - if (map->m_la >= inode->i_size) { + if (map->m_la >= inode->i_size) { /* post-EOF unmapped extent */ map->m_llen = map->m_la + 1 - inode->i_size; map->m_la = inode->i_size; map->m_flags = 0; - goto out; - } - - err = z_erofs_fill_inode_lazy(inode); - if (err) - goto out; - - if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) && - !vi->z_tailextent_headlcn) { - map->m_la = 0; - map->m_llen = inode->i_size; - map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_FULL_MAPPED | - EROFS_MAP_FRAGMENT; - goto out; + } else { + err = z_erofs_fill_inode_lazy(inode); + if (!err) { + if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) && + !vi->z_tailextent_headlcn) { + map->m_la = 0; + map->m_llen = inode->i_size; + map->m_flags = EROFS_MAP_MAPPED | + EROFS_MAP_FULL_MAPPED | EROFS_MAP_FRAGMENT; + } else { + err = z_erofs_do_map_blocks(inode, map, flags); + } + } + if (!err && (map->m_flags & EROFS_MAP_ENCODED) && + unlikely(map->m_plen > Z_EROFS_PCLUSTER_MAX_SIZE || + map->m_llen > Z_EROFS_PCLUSTER_MAX_DSIZE)) + err = -EOPNOTSUPP; + if (err) + map->m_llen = 0; } - - err = z_erofs_do_map_blocks(inode, map, flags); -out: - if (err) - map->m_llen = 0; trace_erofs_map_blocks_exit(inode, map, flags, err); return err; } |