[0/2] Fix direct write with respect to inode locking

Message

Goldwyn Rodrigues Dec. 8, 2020, 6:42 p.m. UTC

From: Goldwyn Rodrigues <[e-mail]>

In my previous attempt to fix direct I/O using iomap, the inode locks
were pushed into respective direct and buffered writes. However, in case
of fallback to buffered write, direct-io would release the inode lock and
reacquire it for buffered. This can cause corruption if another process
acquires the lock in between and writes around the same offset. Change
the flow so that the lock is acquired at the begining and release only
after the fallback buffered is complete.


Goldwyn Rodrigues (2):
  btrfs: Fold generic_write_checks() in btrfs_write_check()
  btrfs: Make btrfs_direct_write atomic with respect to inode_lock

 fs/btrfs/file.c | 86 ++++++++++++++++++++++++++-----------------------
 1 file changed, 46 insertions(+), 40 deletions(-)