[v2,0/2] btrfs: some fiemap fixes

Message

Filipe Manana Feb. 23, 2024, 3:19 p.m. UTC

From: Filipe Manana <[e-mail]>

There's a recent regression with fiemap due to a fix for a deadlock between
fiemap and memory mapped writes when the fiemap buffer is memory mapped to
the same file range, which leads to a race triggering a warning and making
fiemap fail. Plus one more long standing race when using FIEMAP_FLAG_SYNC.
Details in the change logs.

V2: Updated patch 1/2 to deal with the case of a hole/prealloc extent
    with multiple delalloc ranges inside it.

Filipe Manana (2):
  btrfs: fix race between ordered extent completion and fiemap
  btrfs: ensure fiemap doesn't race with writes when FIEMAP_FLAG_SYNC is given

 fs/btrfs/extent_io.c | 60 +++++++++++++++++++++++++++++++-------------
 fs/btrfs/inode.c     | 22 +++++++++++++++-
 2 files changed, 64 insertions(+), 18 deletions(-)