[PATCH 4/4] xfs: Protect xfs_file_aio_write() with sb_start_write - sb_end_write
From: Jan Kara <jack@suse.cz>
Date: 2012-01-12 01:20:53
Also in:
linux-fsdevel, linux-xfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
Replace racy xfs_wait_for_freeze() check with reliable sb_start_write() - sb_end_write() locking. Due to lock ranking dictated by the page fault code we have to call sb_start_write() after we acquire ilock. CC: Ben Myers <redacted> CC: Alex Elder <elder@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> --- fs/xfs/xfs_file.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 753ed9b..c5f879b 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c@@ -862,9 +862,11 @@ xfs_file_dio_aio_write( *iolock = XFS_IOLOCK_SHARED; } + sb_start_write(inode->i_sb); trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0); ret = generic_file_direct_write(iocb, iovp, &nr_segs, pos, &iocb->ki_pos, count, ocount); + sb_end_write(inode->i_sb); /* No fallback to buffered IO on errors for XFS. */ ASSERT(ret < 0 || ret == count);
@@ -899,6 +901,7 @@ xfs_file_buffered_aio_write( /* We can write back this queue in page reclaim */ current->backing_dev_info = mapping->backing_dev_info; + sb_start_write(inode->i_sb); write_retry: trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0); ret = generic_file_buffered_write(iocb, iovp, nr_segs,
@@ -914,6 +917,7 @@ write_retry: enospc = 1; goto write_retry; } + sb_end_write(inode->i_sb); current->backing_dev_info = NULL; return ret; }
@@ -945,8 +949,6 @@ xfs_file_aio_write( if (ocount == 0) return 0; - xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);