xfs: remove xfs_iread

There is not much point in the xfs_iread function, as it has a single
caller and not a whole lot of code.  Move it into the only caller,
and trim down the overdocumentation to just documenting the important
"why" instead of a lot of redundant "what".

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

1 files changed, 32 insertions, 1 deletions

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 922a29032e37..af5748f5d927 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -22,6 +22,7 @@
 #include "xfs_dquot_item.h"
 #include "xfs_dquot.h"
 #include "xfs_reflink.h"
+#include "xfs_ialloc.h"
 
 #include <linux/iversion.h>
 
@@ -508,10 +509,40 @@ xfs_iget_cache_miss(
 	if (!ip)
 		return -ENOMEM;
 
-	error = xfs_iread(mp, tp, ip, flags);
+	error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags);
 	if (error)
 		goto out_destroy;
 
+	/*
+	 * For version 5 superblocks, if we are initialising a new inode and we
+	 * are not utilising the XFS_MOUNT_IKEEP inode cluster mode, we can
+	 * simply build the new inode core with a random generation number.
+	 *
+	 * For version 4 (and older) superblocks, log recovery is dependent on
+	 * the di_flushiter field being initialised from the current on-disk
+	 * value and hence we must also read the inode off disk even when
+	 * initializing new inodes.
+	 */
+	if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
+	    (flags & XFS_IGET_CREATE) && !(mp->m_flags & XFS_MOUNT_IKEEP)) {
+		VFS_I(ip)->i_generation = prandom_u32();
+	} else {
+		struct xfs_dinode	*dip;
+		struct xfs_buf		*bp;
+
+		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0);
+		if (error)
+			goto out_destroy;
+
+		error = xfs_inode_from_disk(ip, dip);
+		if (!error)
+			xfs_buf_set_ref(bp, XFS_INO_REF);
+		xfs_trans_brelse(tp, bp);
+
+		if (error)
+			goto out_destroy;
+	}
+
 	if (!xfs_inode_verify_forks(ip)) {
 		error = -EFSCORRUPTED;
 		goto out_destroy;