Re: [PATCH 18/27] xfs: Convert to new freezing code
From: Dave Chinner <hidden>
Date: 2012-06-05 04:16:24
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linux-fsdevel
On Sat, Jun 02, 2012 at 12:30:32AM +0200, Jan Kara wrote:
Generic code now blocks all writers from standard write paths. So we add blocking of all writers coming from ioctl (we get a protection of ioctl against racing remount read-only as a bonus) and convert xfs_file_aio_write() to a non-racy freeze protection. We also keep freeze protection on transaction start to block internal filesystem writes such as removal of preallocated blocks.
I don't think this will apply to a current TOT XFS - the end_io context hunks look wrong. Perhaps your rebased this before the XFS tree was merged?
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CC: Ben Myers <redacted> CC: Alex Elder <elder@kernel.org> CC: xfs@oss.sgi.com Signed-off-by: Jan Kara <jack@suse.cz> --- fs/xfs/xfs_aops.c | 18 ++++++++++++++++ fs/xfs/xfs_file.c | 10 ++++++-- fs/xfs/xfs_ioctl.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++-- fs/xfs/xfs_ioctl32.c | 12 ++++++++++ fs/xfs/xfs_iomap.c | 4 +- fs/xfs/xfs_mount.c | 2 +- fs/xfs/xfs_mount.h | 3 -- fs/xfs/xfs_sync.c | 2 +- fs/xfs/xfs_trans.c | 17 ++++++++++++-- fs/xfs/xfs_trans.h | 2 + 10 files changed, 109 insertions(+), 16 deletions(-)diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index ae31c31..4a001b8 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c@@ -124,6 +124,12 @@ xfs_setfilesize_trans_alloc( ioend->io_append_trans = tp; /* + * We will pass freeze protection with a transaction. So tell lockdep + * we released it. + */ + rwsem_release(&ioend->io_inode->i_sb->s_writers.lock_map[SB_FREEZE_FS-1], + 1, _THIS_IP_); + /*
Oh, that's rather ugly. If this is necessary where a transaction handle is passed to another thread and completed there, then this really needs to be wrapped in helper functions so it is always done correctly when the PF_TRANS flag is also transferred. That can be done later, though. It will also need to be done to the allocation code which passes allocation off to a workqueue, but that is currently synchronous so won't be a problem for this change right now...
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@@ -631,7 +638,11 @@ xfs_ioc_space( if (ioflags & IO_INVIS) attr_flags |= XFS_ATTR_DMI; + error = mnt_want_write_file(filp); + if (error) + return error; error = xfs_change_file_space(ip, cmd, bf, filp->f_pos, attr_flags); + mnt_drop_write_file(filp); return -error;
Those positive/negative error conversions are starting to get confusing and difficult to get right. I'm going to have to convert XFS at some point to return negative errors everywhere so we can get rid of that problem once and for all... Otherwise, this looks OK. I'll need to pull this in and test it, but the I was using the previous version of the patch series for almost the entire 3.4-rc cycle and didn't come across any problems with it.... Cheers, Dave. -- Dave Chinner dchinner@redhat.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs