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authorChristoph Hellwig <hch@lst.de>2009-08-31 21:00:31 -0300
committerFelix Blyakher <felixb@sgi.com>2009-09-01 12:45:57 -0500
commit13e6d5cdde0e785aa943810f08b801cadd0935df (patch)
tree72b62d1e3e4b35f1613458b6e1dbbadd74534a92 /fs/xfs/xfs_rw.c
parentbd169565993b39b9b4b102cdac8b13e0a259ce2f (diff)
xfs: merge fsync and O_SYNC handling
The guarantees for O_SYNC are exactly the same as the ones we need to make for an fsync call (and given that Linux O_SYNC is O_DSYNC the equivalent is fdadatasync, but we treat both the same in XFS), except with a range data writeout. Jan Kara has started unifying these two path for filesystems using the generic helpers, and I've started to look at XFS. The actual transaction commited by xfs_fsync and xfs_write_sync_logforce has a different transaction number, but actually is exactly the same. We'll only use the fsync transaction going forward. One major difference is that xfs_write_sync_logforce never issues a cache flush unless we commit a transaction causing that as a side-effect, which is an obvious bug in the O_SYNC handling. Second all the locking and i_update_size vs i_update_core changes from 978b7237123d007b9fa983af6e0e2fa8f97f9934 never made it to xfs_write_sync_logforce, so we add them back. To make xfs_fsync easily usable from the O_SYNC path, the filemap_fdatawait call is moved up to xfs_file_fsync, so that we don't wait on the whole file after we already waited for our portion in xfs_write. We'll also use a plain call to filemap_write_and_wait_range instead of the previous sync_page_rang which did it in two steps including an half-hearted inode write out that doesn't help us. Once we're done with this also remove the now useless i_update_size tracking. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Felix Blyakher <felixb@sgi.com> Signed-off-by: Felix Blyakher <felixb@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_rw.c')
-rw-r--r--fs/xfs/xfs_rw.c84
1 files changed, 0 insertions, 84 deletions
diff --git a/fs/xfs/xfs_rw.c b/fs/xfs/xfs_rw.c
index fea68615ed23..3f816ad7ff19 100644
--- a/fs/xfs/xfs_rw.c
+++ b/fs/xfs/xfs_rw.c
@@ -88,90 +88,6 @@ xfs_write_clear_setuid(
}
/*
- * Handle logging requirements of various synchronous types of write.
- */
-int
-xfs_write_sync_logforce(
- xfs_mount_t *mp,
- xfs_inode_t *ip)
-{
- int error = 0;
-
- /*
- * If we're treating this as O_DSYNC and we have not updated the
- * size, force the log.
- */
- if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC) &&
- !(ip->i_update_size)) {
- xfs_inode_log_item_t *iip = ip->i_itemp;
-
- /*
- * If an allocation transaction occurred
- * without extending the size, then we have to force
- * the log up the proper point to ensure that the
- * allocation is permanent. We can't count on
- * the fact that buffered writes lock out direct I/O
- * writes - the direct I/O write could have extended
- * the size nontransactionally, then finished before
- * we started. xfs_write_file will think that the file
- * didn't grow but the update isn't safe unless the
- * size change is logged.
- *
- * Force the log if we've committed a transaction
- * against the inode or if someone else has and
- * the commit record hasn't gone to disk (e.g.
- * the inode is pinned). This guarantees that
- * all changes affecting the inode are permanent
- * when we return.
- */
- if (iip && iip->ili_last_lsn) {
- error = _xfs_log_force(mp, iip->ili_last_lsn,
- XFS_LOG_FORCE | XFS_LOG_SYNC, NULL);
- } else if (xfs_ipincount(ip) > 0) {
- error = _xfs_log_force(mp, (xfs_lsn_t)0,
- XFS_LOG_FORCE | XFS_LOG_SYNC, NULL);
- }
-
- } else {
- xfs_trans_t *tp;
-
- /*
- * O_SYNC or O_DSYNC _with_ a size update are handled
- * the same way.
- *
- * If the write was synchronous then we need to make
- * sure that the inode modification time is permanent.
- * We'll have updated the timestamp above, so here
- * we use a synchronous transaction to log the inode.
- * It's not fast, but it's necessary.
- *
- * If this a dsync write and the size got changed
- * non-transactionally, then we need to ensure that
- * the size change gets logged in a synchronous
- * transaction.
- */
- tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC);
- if ((error = xfs_trans_reserve(tp, 0,
- XFS_SWRITE_LOG_RES(mp),
- 0, 0, 0))) {
- /* Transaction reserve failed */
- xfs_trans_cancel(tp, 0);
- } else {
- /* Transaction reserve successful */
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
- xfs_trans_ihold(tp, ip);
- xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
- xfs_trans_set_sync(tp);
- error = xfs_trans_commit(tp, 0);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- }
- }
-
- return error;
-}
-
-/*
* Force a shutdown of the filesystem instantly while keeping
* the filesystem consistent. We don't do an unmount here; just shutdown
* the shop, make sure that absolutely nothing persistent happens to