xfs: pull up iolock from xfs_free_eofblocks()

xfs_free_eofblocks() requires the IOLOCK_EXCL lock, but is called from
different contexts where the lock may or may not be held. The
need_iolock parameter exists for this reason, to indicate whether
xfs_free_eofblocks() must acquire the iolock itself before it can
proceed.

This is ugly and confusing. Simplify the semantics of
xfs_free_eofblocks() to require the caller to acquire the iolock
appropriately and kill the need_iolock parameter. While here, the mp
param can be removed as well as the xfs_mount is accessible from the
xfs_inode structure. This patch does not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

1 files changed, 28 insertions, 23 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index de32f0fe47c8..edfa6a55b064 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1692,32 +1692,34 @@ xfs_release(
         if (xfs_can_free_eofblocks(ip, false)) {
 
                 /*
+                 * Check if the inode is being opened, written and closed
+                 * frequently and we have delayed allocation blocks outstanding
+                 * (e.g. streaming writes from the NFS server), truncating the
+                 * blocks past EOF will cause fragmentation to occur.
+                 *
+                 * In this case don't do the truncation, but we have to be
+                 * careful how we detect this case. Blocks beyond EOF show up as
+                 * i_delayed_blks even when the inode is clean, so we need to
+                 * truncate them away first before checking for a dirty release.
+                 * Hence on the first dirty close we will still remove the
+                 * speculative allocation, but after that we will leave it in
+                 * place.
+                 */
+                if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
+                        return 0;
+                /*
                  * If we can't get the iolock just skip truncating the blocks
                  * past EOF because we could deadlock with the mmap_sem
-                 * otherwise.  We'll get another chance to drop them once the
+                 * otherwise. We'll get another chance to drop them once the
                  * last reference to the inode is dropped, so we'll never leak
                  * blocks permanently.
-                 *
-                 * Further, check if the inode is being opened, written and
-                 * closed frequently and we have delayed allocation blocks
-                 * outstanding (e.g. streaming writes from the NFS server),
-                 * truncating the blocks past EOF will cause fragmentation to
-                 * occur.
-                 *
-                 * In this case don't do the truncation, either, but we have to
-                 * be careful how we detect this case. Blocks beyond EOF show
-                 * up as i_delayed_blks even when the inode is clean, so we
-                 * need to truncate them away first before checking for a dirty
-                 * release. Hence on the first dirty close we will still remove
-                 * the speculative allocation, but after that we will leave it
-                 * in place.
                  */
-                if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
-                        return 0;
-
-                error = xfs_free_eofblocks(mp, ip, true);
-                if (error && error != -EAGAIN)
-                        return error;
+                if (xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
+                        error = xfs_free_eofblocks(ip);
+                        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+                        if (error)
+                                return error;
+                }
 
                 /* delalloc blocks after truncation means it really is dirty */
                 if (ip->i_delayed_blks)
@@ -1904,8 +1906,11 @@ xfs_inactive(
                  * cache. Post-eof blocks must be freed, lest we end up with
                  * broken free space accounting.
                  */
-                if (xfs_can_free_eofblocks(ip, true))
-                        xfs_free_eofblocks(mp, ip, false);
+                if (xfs_can_free_eofblocks(ip, true)) {
+                        xfs_ilock(ip, XFS_IOLOCK_EXCL);
+                        xfs_free_eofblocks(ip);
+                        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+                }
 
                 return;
         }