6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ism Hong ism.hong@gmail.com
[ Upstream commit d6d33f03baa43d763fe094ca926eeae7d3421d07 ]
Since the buffer cache for ntfs3 metadata is not released until the file system is unmounted, allocating from the movable zone may result in cma allocation failures. This is due to the page still being used by ntfs3, leading to migration failures.
To address this, this commit use sb_bread_umovable() instead of sb_bread(). This change prevents allocation from the movable zone, ensuring compatibility with scenarios where the buffer head is not released until unmount. This patch is inspired by commit a8ac900b8163("ext4: use non-movable memory for the ext4 superblock").
The issue is found when playing video files stored in NTFS on the Android TV platform. During this process, the media parser reads the video file, causing ntfs3 to allocate buffer cache from the CMA area. Subsequently, the hardware decoder attempts to allocate memory from the same CMA area. However, the page is still in use by ntfs3, resulting in a migrate failure in alloc_contig_range().
The pinned page and allocating stacktrace reported by page owner shows below:
page:ffffffff00b68880 refcount:3 mapcount:0 mapping:ffffff80046aa828 index:0xc0040 pfn:0x20fa4 aops:def_blk_aops ino:0 flags: 0x2020(active|private) page dumped because: migration failure page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48 (GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), page_owner tracks the page as allocated prep_new_page get_page_from_freelist __alloc_pages_nodemask pagecache_get_page __getblk_gfp __bread_gfp ntfs_read_run_nb ntfs_read_bh mi_read ntfs_iget5 dir_search_u ntfs_lookup __lookup_slow lookup_slow walk_component path_lookupat
Signed-off-by: Ism Hong ism.hong@gmail.com Signed-off-by: Konstantin Komarov almaz.alexandrovich@paragon-software.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ntfs3/ntfs_fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h index c71a1eca427a3..98906e4675171 100644 --- a/fs/ntfs3/ntfs_fs.h +++ b/fs/ntfs3/ntfs_fs.h @@ -1035,7 +1035,7 @@ static inline u64 bytes_to_block(const struct super_block *sb, u64 size) static inline struct buffer_head *ntfs_bread(struct super_block *sb, sector_t block) { - struct buffer_head *bh = sb_bread(sb, block); + struct buffer_head *bh = sb_bread_unmovable(sb, block);
if (bh) return bh;