mbox series

[v2,0/2] Fix locking for btrfs direct writes

Message ID cover.1608053602.git.rgoldwyn@suse.com (mailing list archive)
Headers show
Series Fix locking for btrfs direct writes | expand

Message

Goldwyn Rodrigues Dec. 15, 2020, 6:06 p.m. UTC 
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

BTRFS direct write takes the inode lock for performing the direct write.
In case of a failure or an incomplete write, it falls back to buffered
writes. Before initiating the buffered write, it releases the inode lock
and reacquires it for buffered write. This may lead to corruption if
another process attempts to write around the same offset between the
unlock and the relock. The patches change the flow so that the lock is
taken only once before the write and released only after the I/O is
complete.


Goldwyn Rodrigues (2):
  iomap: Separate out generic_write_sync() from iomap_dio_complete()
  btrfs: Make btrfs_direct_write atomic with respect to inode_lock

 fs/btrfs/file.c       | 69 +++++++++++++++++++++++++------------------
 fs/iomap/direct-io.c  | 16 ++++++++--
 include/linux/iomap.h |  2 +-
 3 files changed, 54 insertions(+), 33 deletions(-)