| Message ID | 20210111161544.1414409-2-hch@lst.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] xfs: refactor xfs_file_fsync | expand |
On Mon, Jan 11, 2021 at 05:15:43PM +0100, Christoph Hellwig wrote: > Factor out the log syncing logic into two helpers to make the code easier > to read and more maintainable. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- Looks fine, though it might be nice to find some commonality with xfs_log_force_inode(): Reviewed-by: Brian Foster <bfoster@redhat.com> > fs/xfs/xfs_file.c | 81 +++++++++++++++++++++++++++++------------------ > 1 file changed, 50 insertions(+), 31 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 5b0f93f738372d..414d856e2e755a 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -118,6 +118,54 @@ xfs_dir_fsync( > return xfs_log_force_inode(ip); > } > > +static xfs_lsn_t > +xfs_fsync_lsn( > + struct xfs_inode *ip, > + bool datasync) > +{ > + if (!xfs_ipincount(ip)) > + return 0; > + if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) > + return 0; > + return ip->i_itemp->ili_last_lsn; > +} > + > +/* > + * All metadata updates are logged, which means that we just have to flush the > + * log up to the latest LSN that touched the inode. > + * > + * If we have concurrent fsync/fdatasync() calls, we need them to all block on > + * the log force before we clear the ili_fsync_fields field. This ensures that > + * we don't get a racing sync operation that does not wait for the metadata to > + * hit the journal before returning. If we race with clearing ili_fsync_fields, > + * then all that will happen is the log force will do nothing as the lsn will > + * already be on disk. We can't race with setting ili_fsync_fields because that > + * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock > + * shared until after the ili_fsync_fields is cleared. > + */ > +static int > +xfs_fsync_flush_log( > + struct xfs_inode *ip, > + bool datasync, > + int *log_flushed) > +{ > + int error = 0; > + xfs_lsn_t lsn; > + > + xfs_ilock(ip, XFS_ILOCK_SHARED); > + lsn = xfs_fsync_lsn(ip, datasync); > + if (lsn) { > + error = xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, > + log_flushed); > + > + spin_lock(&ip->i_itemp->ili_lock); > + ip->i_itemp->ili_fsync_fields = 0; > + spin_unlock(&ip->i_itemp->ili_lock); > + } > + xfs_iunlock(ip, XFS_ILOCK_SHARED); > + return error; > +} > + > STATIC int > xfs_file_fsync( > struct file *file, > @@ -125,13 +173,10 @@ xfs_file_fsync( > loff_t end, > int datasync) > { > - struct inode *inode = file->f_mapping->host; > - struct xfs_inode *ip = XFS_I(inode); > - struct xfs_inode_log_item *iip = ip->i_itemp; > + struct xfs_inode *ip = XFS_I(file->f_mapping->host); > struct xfs_mount *mp = ip->i_mount; > int error = 0; > int log_flushed = 0; > - xfs_lsn_t lsn = 0; > > trace_xfs_file_fsync(ip); > > @@ -155,33 +200,7 @@ xfs_file_fsync( > else if (mp->m_logdev_targp != mp->m_ddev_targp) > xfs_blkdev_issue_flush(mp->m_ddev_targp); > > - /* > - * All metadata updates are logged, which means that we just have to > - * flush the log up to the latest LSN that touched the inode. If we have > - * concurrent fsync/fdatasync() calls, we need them to all block on the > - * log force before we clear the ili_fsync_fields field. This ensures > - * that we don't get a racing sync operation that does not wait for the > - * metadata to hit the journal before returning. If we race with > - * clearing the ili_fsync_fields, then all that will happen is the log > - * force will do nothing as the lsn will already be on disk. We can't > - * race with setting ili_fsync_fields because that is done under > - * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared > - * until after the ili_fsync_fields is cleared. > - */ > - xfs_ilock(ip, XFS_ILOCK_SHARED); > - if (xfs_ipincount(ip)) { > - if (!datasync || > - (iip->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) > - lsn = iip->ili_last_lsn; > - } > - > - if (lsn) { > - error = xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed); > - spin_lock(&iip->ili_lock); > - iip->ili_fsync_fields = 0; > - spin_unlock(&iip->ili_lock); > - } > - xfs_iunlock(ip, XFS_ILOCK_SHARED); > + error = xfs_fsync_flush_log(ip, datasync, &log_flushed); > > /* > * If we only have a single device, and the log force about was > -- > 2.29.2 >
On Tue, Jan 12, 2021 at 10:33:47AM -0500, Brian Foster wrote: > Looks fine, though it might be nice to find some commonality with > xfs_log_force_inode(): The common logic is called xfs_log_force_lsn :) The fact that fsync checks and modifies ili_fsync_fields makes it rather impractival to share more code unfortunately.
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 5b0f93f738372d..414d856e2e755a 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -118,6 +118,54 @@ xfs_dir_fsync( return xfs_log_force_inode(ip); } +static xfs_lsn_t +xfs_fsync_lsn( + struct xfs_inode *ip, + bool datasync) +{ + if (!xfs_ipincount(ip)) + return 0; + if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) + return 0; + return ip->i_itemp->ili_last_lsn; +} + +/* + * All metadata updates are logged, which means that we just have to flush the + * log up to the latest LSN that touched the inode. + * + * If we have concurrent fsync/fdatasync() calls, we need them to all block on + * the log force before we clear the ili_fsync_fields field. This ensures that + * we don't get a racing sync operation that does not wait for the metadata to + * hit the journal before returning. If we race with clearing ili_fsync_fields, + * then all that will happen is the log force will do nothing as the lsn will + * already be on disk. We can't race with setting ili_fsync_fields because that + * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock + * shared until after the ili_fsync_fields is cleared. + */ +static int +xfs_fsync_flush_log( + struct xfs_inode *ip, + bool datasync, + int *log_flushed) +{ + int error = 0; + xfs_lsn_t lsn; + + xfs_ilock(ip, XFS_ILOCK_SHARED); + lsn = xfs_fsync_lsn(ip, datasync); + if (lsn) { + error = xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, + log_flushed); + + spin_lock(&ip->i_itemp->ili_lock); + ip->i_itemp->ili_fsync_fields = 0; + spin_unlock(&ip->i_itemp->ili_lock); + } + xfs_iunlock(ip, XFS_ILOCK_SHARED); + return error; +} + STATIC int xfs_file_fsync( struct file *file, @@ -125,13 +173,10 @@ xfs_file_fsync( loff_t end, int datasync) { - struct inode *inode = file->f_mapping->host; - struct xfs_inode *ip = XFS_I(inode); - struct xfs_inode_log_item *iip = ip->i_itemp; + struct xfs_inode *ip = XFS_I(file->f_mapping->host); struct xfs_mount *mp = ip->i_mount; int error = 0; int log_flushed = 0; - xfs_lsn_t lsn = 0; trace_xfs_file_fsync(ip); @@ -155,33 +200,7 @@ xfs_file_fsync( else if (mp->m_logdev_targp != mp->m_ddev_targp) xfs_blkdev_issue_flush(mp->m_ddev_targp); - /* - * All metadata updates are logged, which means that we just have to - * flush the log up to the latest LSN that touched the inode. If we have - * concurrent fsync/fdatasync() calls, we need them to all block on the - * log force before we clear the ili_fsync_fields field. This ensures - * that we don't get a racing sync operation that does not wait for the - * metadata to hit the journal before returning. If we race with - * clearing the ili_fsync_fields, then all that will happen is the log - * force will do nothing as the lsn will already be on disk. We can't - * race with setting ili_fsync_fields because that is done under - * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared - * until after the ili_fsync_fields is cleared. - */ - xfs_ilock(ip, XFS_ILOCK_SHARED); - if (xfs_ipincount(ip)) { - if (!datasync || - (iip->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) - lsn = iip->ili_last_lsn; - } - - if (lsn) { - error = xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed); - spin_lock(&iip->ili_lock); - iip->ili_fsync_fields = 0; - spin_unlock(&iip->ili_lock); - } - xfs_iunlock(ip, XFS_ILOCK_SHARED); + error = xfs_fsync_flush_log(ip, datasync, &log_flushed); /* * If we only have a single device, and the log force about was
Factor out the log syncing logic into two helpers to make the code easier to read and more maintainable. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/xfs_file.c | 81 +++++++++++++++++++++++++++++------------------ 1 file changed, 50 insertions(+), 31 deletions(-)