kernel.git/fs/bcachefs, branch linux-6.15.y

bcachefs: Fix subvol to missing root repair

2025-06-10T11:17:09Z

commit 29cc6fb7c068c773049d3bde14b939033893eff4 upstream. We had a bug where the root inode of a subvolume was erronously deleted: bch2_evict_inode() called bch2_inode_rm(), meaning the VFS inode's i_nlink was somehow set to 0 when it shouldn't have - the inode in the btree indicated it clearly was not unlinked. This has been addressed with additional safety checks in bch2_inode_rm() - pulling in the safety checks we already were doing when deleting unlinked inodes in recovery - but the really disastrous bug was in check_subvols(), which on finding a dangling subvol (subvol with a missing root inode) would delete the subvolume. I assume this bug dates from early check_directory_structure() code, which originally handled subvolumes and normal paths - the idea being that still live contents of the subvolume would get reattached somewhere. But that's incorrect, and disastrously so; deleting a subvolume triggers deleting the snapshot ID it points to, deleting the entire contents. The correct way to repair is to recreate the root inode if it's missing; then any contents will get reattached under that subvolume's lost+found. Signed-off-by: Kent Overstreet Signed-off-by: Greg Kroah-Hartman

bcachefs: Run may_delete_deleted_inode() checks in bch2_inode_rm()

2025-06-10T11:17:09Z

commit 09fb85ae565645b982e9030dbb2ff6707f2cdddc upstream. We had a bug where bch2_evict_inode() incorrectly called bch2_inode_rm() - the journal clearly showed the inode was not unlinked. We've got checks that we use in recovery when cleaning up deleted inodes, lift them to bch2_inode_rm() as well. Signed-off-by: Kent Overstreet Signed-off-by: Greg Kroah-Hartman

bcachefs: delete dead code from may_delete_deleted_inode()

2025-06-10T11:17:09Z

commit bb6689bbeebc6fb51f0f120b486bdcc9a38ffcf6 upstream. Signed-off-by: Kent Overstreet Signed-off-by: Greg Kroah-Hartman

bcachefs: Repair code for directory i_size

2025-06-10T11:17:09Z

commit 36a2fdf7c5c1ccae6ca16cd14067567096cebe17 upstream. We had a bug due due to an incomplete revert of the patch implementing directory i_size (summing up the size of the dirents), leading to completely screwy i_size values that underflow. Most userspace programs don't seem to care (e.g. du ignores it), but it turns out this broke sshfs, so needs to be repaired. Signed-off-by: Kent Overstreet Signed-off-by: Greg Kroah-Hartman

bcachefs: Kill un-reverted directory i_size code

2025-06-10T11:17:09Z

commit 95fafc0f3407a6446082c11849df585bd3246571 upstream. Signed-off-by: Kent Overstreet Signed-off-by: Greg Kroah-Hartman

bcachefs: Check for casefolded dirents in non casefolded dirs

2025-05-22T00:13:14Z

Check for mismatches between casefold dirents and casefold directories. A mismatch will cause lookups to fail, as we'll be doing the lookup with the casefolded name, which won't match the non-casefolded dirent, and vice versa. Reported-by: Christopher Snowhill Signed-off-by: Kent Overstreet

bcachefs: Fix bch2_dirent_create_snapshot() for casefolding

2025-05-22T00:13:13Z

bch2_dirent_create_snapshot(), used in fsck, neglected to create a casefolded dirent. Just move this into dirent_create_key(). Signed-off-by: Kent Overstreet

bcachefs: Fix casefold opt via xattr interface

2025-05-22T00:13:09Z

Changing the casefold option requires extra checks/work - factor out a helper from bch2_fileattr_set() for the xattr code to use. Signed-off-by: Kent Overstreet

bcachefs: mkwrite() now only dirties one page

2025-05-19T12:28:41Z

Don't dirty the whole folio - fixes write amplification with applications doing mmaped writes. https://www.reddit.com/r/bcachefs/comments/1klzcg1/incredible_amounts_of_write_amplification_when/ Signed-off-by: Kent Overstreet

bcachefs: fix extent_has_stripe_ptr()

2025-05-19T02:35:33Z

This wasn't checking indirect extents. Fixes: https://github.com/koverstreet/bcachefs/issues/887 Signed-off-by: Kent Overstreet