| Message ID | 1326331253-6497-5-git-send-email-jack@suse.cz |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Thu, Jan 12, 2012 at 02:20:53AM +0100, Jan Kara wrote: > 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 <bpm@sgi.com> > 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); What lock ordering do you have in mind? Explicit description in fs/super.c, please... -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu 12-01-12 21:29:41, Al Viro wrote: > On Thu, Jan 12, 2012 at 02:20:53AM +0100, Jan Kara wrote: > > 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 <bpm@sgi.com> > > 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); > > What lock ordering do you have in mind? Explicit description in fs/super.c, > please... Good point. Will add explanatory comment. Thanks. Honza
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); - if (XFS_FORCED_SHUTDOWN(ip->i_mount)) return -EIO;
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 <bpm@sgi.com> 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(-)