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| author | Hyunchul Lee <hyc.lee@gmail.com> | 2026-09-15 00:19:15 +0900 |
|---|---|---|
| committer | Namjae Jeon <linkinjeon@kernel.org> | 2026-09-15 21:31:26 +0900 |
| commit | 56b4f864e199c67f9bfa61bb8e7dc08f1eb20ce1 (patch) | |
| tree | a8a3a623a29ac371146a9658f6fee312525c9276 | |
| parent | 8809c3f29555f9d1e66fe015080a8d4979d91eaa (diff) | |
| download | linux-next-56b4f864e199c67f9bfa61bb8e7dc08f1eb20ce1.tar.gz linux-next-56b4f864e199c67f9bfa61bb8e7dc08f1eb20ce1.zip | |
ntfs: avoid truncate and writeback deadlock
ntfs_non_resident_attr_shrink() drops page-cache folios after freeing
clusters and truncating the runlist. The VFS truncate path calls it with
mrec_lock held. A folio writeback can need the same lock to resolve its
iomap mapping, so truncate can wait for writeback while writeback waits
for mrec_lock.
A hung-task call stack:
truncate: mrec_lock -> truncate_inode_pages() -> folio lock/writeback
writeback: folio lock/writeback -> ntfs_write_iomap_begin() ->
mrec_lock
ntfs_setattr_size() already calls truncate_setsize() before
ntfs_truncate_vfs() acquires mrec_lock. Reuse that page-cache truncation
in the VFS path and skip the duplicate truncation under mrec_lock. Keep
the cleanup for internal attribute callers, which do not call
truncate_setsize(). This avoids synchronously flushing the whole
discarded tail while preserving page-cache correctness.
Fixes: 4e646ecd4475 ("ntfs: drop stale page-cache when shrinking a non-resident attr")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
| -rw-r--r-- | fs/ntfs/attrib.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index c7c09a751c6a..b01cbc9eea4a 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -4234,12 +4234,14 @@ static int ntfs_attr_make_resident(struct ntfs_inode *ni, struct ntfs_attr_searc * ntfs_non_resident_attr_shrink - shrink a non-resident, open ntfs attribute * @ni: non-resident ntfs attribute to shrink * @newsize: new size (in bytes) to which to shrink the attribute + * @pagecache_truncated: page cache was already truncated to @newsize * * Reduce the size of a non-resident, open ntfs attribute @na to @newsize bytes. */ static int ntfs_non_resident_attr_shrink(struct ntfs_inode *ni, const s64 newsize, - struct ntfs_inode *locked_ni) + struct ntfs_inode *locked_ni, + bool pagecache_truncated) { struct ntfs_volume *vol; struct ntfs_attr_search_ctx *ctx; @@ -4389,7 +4391,8 @@ static int ntfs_non_resident_attr_shrink(struct ntfs_inode *ni, * later writeback map a vcn past the new allocation, which fails with * -ENOENT and loses the write. */ - truncate_inode_pages(VFS_I(ni)->i_mapping, newsize); + if (!pagecache_truncated) + truncate_inode_pages(VFS_I(ni)->i_mapping, newsize); /* Update data size in the index. */ if (ni->type == AT_DATA && ni->name == AT_UNNAMED) @@ -4991,7 +4994,7 @@ int __ntfs_attr_truncate_vfs(struct ntfs_inode *ni, const s64 newsize, up_write(&ni->runlist.lock); } else err = ntfs_non_resident_attr_shrink( - ni, newsize, NULL); + ni, newsize, NULL, true); } else err = ntfs_resident_attr_resize(ni, newsize, 0, NVolDisableSparse(ni->vol) ? @@ -5104,7 +5107,7 @@ int ntfs_attr_truncate_i_locked(struct ntfs_inode *ni, const s64 newsize, ni, newsize, 0, holes, locked_ni); else err = ntfs_non_resident_attr_shrink( - ni, newsize, locked_ni); + ni, newsize, locked_ni, false); } else err = ntfs_resident_attr_resize(ni, newsize, 0, holes); ntfs_debug("Return status %d\n", err); |