diff options
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/file.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 77202addead8..0a46fff3dd06 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1458,8 +1458,13 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) if (iocb->ki_flags & IOCB_NOWAIT) ilock_flags |= BTRFS_ILOCK_TRY; - /* If the write DIO is within EOF, use a shared lock */ - if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode)) + /* + * If the write DIO is within EOF, use a shared lock and also only if + * security bits will likely not be dropped by file_remove_privs() called + * from btrfs_write_check(). Either will need to be rechecked after the + * lock was acquired. + */ + if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode) && IS_NOSEC(inode)) ilock_flags |= BTRFS_ILOCK_SHARED; relock: @@ -1467,6 +1472,13 @@ relock: if (err < 0) return err; + /* Shared lock cannot be used with security bits set. */ + if ((ilock_flags & BTRFS_ILOCK_SHARED) && !IS_NOSEC(inode)) { + btrfs_inode_unlock(inode, ilock_flags); + ilock_flags &= ~BTRFS_ILOCK_SHARED; + goto relock; + } + err = generic_write_checks(iocb, from); if (err <= 0) { btrfs_inode_unlock(inode, ilock_flags); |