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.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/erofs_fs.h | 5 ++++-
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;
}
--
2.43.5
