[GFS2] Fix bug in directory code and tidy up

Due to a typo, the dir leaf split operation was (for the first
split in a directory) writing the new hash vaules at the
wrong offset. This is now fixed.

Also some other tidy ups are included:

 - We use GFS2's hash function for dentries (see ops_dentry.c) so that
   we don't have to keep recalculating the hash values.
 - A lot of common code is eliminated between the various directory
   lookup routines.
 - Better error checking on directory lookup (previously different
   routines checked for different errors)
 - The leaf split operation has a couple of redundant operations
   removed from it, so it should be faster.

There is still further scope for further clean ups in the directory
code, and readdir in particular could do with slimming down a bit.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 30 insertions, 26 deletions

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 8d6d94143561..8d2c557b3ff4 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -379,11 +379,10 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 		goto fail_recoverd;
 	}
 
-	error = gfs2_lookup_simple(sdp->sd_master_dir, "jindex",
-				   &sdp->sd_jindex);
-	if (error) {
+	sdp->sd_jindex = gfs2_lookup_simple(sdp->sd_master_dir, "jindex");
+	if (IS_ERR(sdp->sd_jindex)) {
 		fs_err(sdp, "can't lookup journal index: %d\n", error);
-		return error;
+		return PTR_ERR(sdp->sd_jindex);
 	}
 	ip = sdp->sd_jindex->u.generic_ip;
 	set_bit(GLF_STICKY, &ip->i_gl->gl_flags);
@@ -531,26 +530,26 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 		goto fail_master;
 
 	/* Read in the master inode number inode */
-	error = gfs2_lookup_simple(sdp->sd_master_dir, "inum",
-				   &sdp->sd_inum_inode);
-	if (error) {
+	sdp->sd_inum_inode = gfs2_lookup_simple(sdp->sd_master_dir, "inum");
+	if (IS_ERR(sdp->sd_inum_inode)) {
+		error = PTR_ERR(sdp->sd_inum_inode);
 		fs_err(sdp, "can't read in inum inode: %d\n", error);
 		goto fail_journal;
 	}
 
 
 	/* Read in the master statfs inode */
-	error = gfs2_lookup_simple(sdp->sd_master_dir, "statfs",
-				   &sdp->sd_statfs_inode);
-	if (error) {
+	sdp->sd_statfs_inode = gfs2_lookup_simple(sdp->sd_master_dir, "statfs");
+	if (IS_ERR(sdp->sd_statfs_inode)) {
+		error = PTR_ERR(sdp->sd_statfs_inode);
 		fs_err(sdp, "can't read in statfs inode: %d\n", error);
 		goto fail_inum;
 	}
 
 	/* Read in the resource index inode */
-	error = gfs2_lookup_simple(sdp->sd_master_dir, "rindex",
-				   &sdp->sd_rindex);
-	if (error) {
+	sdp->sd_rindex = gfs2_lookup_simple(sdp->sd_master_dir, "rindex");
+	if (IS_ERR(sdp->sd_rindex)) {
+		error = PTR_ERR(sdp->sd_rindex);
 		fs_err(sdp, "can't get resource index inode: %d\n", error);
 		goto fail_statfs;
 	}
@@ -559,9 +558,9 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 	sdp->sd_rindex_vn = ip->i_gl->gl_vn - 1;
 
 	/* Read in the quota inode */
-	error = gfs2_lookup_simple(sdp->sd_master_dir, "quota",
-				   &sdp->sd_quota_inode);
-	if (error) {
+	sdp->sd_quota_inode = gfs2_lookup_simple(sdp->sd_master_dir, "quota");
+	if (IS_ERR(sdp->sd_quota_inode)) {
+		error = PTR_ERR(sdp->sd_quota_inode);
 		fs_err(sdp, "can't get quota file inode: %d\n", error);
 		goto fail_rindex;
 	}
@@ -600,36 +599,41 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 	if (undo)
 		goto fail_qc_gh;
 
-	error = gfs2_lookup_simple(sdp->sd_master_dir, "per_node", &pn);
-	if (error) {
+	pn = gfs2_lookup_simple(sdp->sd_master_dir, "per_node");
+	if (IS_ERR(pn)) {
+		error = PTR_ERR(pn);
 		fs_err(sdp, "can't find per_node directory: %d\n", error);
 		return error;
 	}
 
 	sprintf(buf, "inum_range%u", sdp->sd_jdesc->jd_jid);
-	error = gfs2_lookup_simple(pn, buf, &sdp->sd_ir_inode);
-	if (error) {
+	sdp->sd_ir_inode = gfs2_lookup_simple(pn, buf);
+	if (IS_ERR(sdp->sd_ir_inode)) {
+		error = PTR_ERR(sdp->sd_ir_inode);
 		fs_err(sdp, "can't find local \"ir\" file: %d\n", error);
 		goto fail;
 	}
 
 	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
-	error = gfs2_lookup_simple(pn, buf, &sdp->sd_sc_inode);
-	if (error) {
+	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
+	if (IS_ERR(sdp->sd_sc_inode)) {
+		error = PTR_ERR(sdp->sd_sc_inode);
 		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
 		goto fail_ir_i;
 	}
 
 	sprintf(buf, "unlinked_tag%u", sdp->sd_jdesc->jd_jid);
-	error = gfs2_lookup_simple(pn, buf, &sdp->sd_ut_inode);
-	if (error) {
+	sdp->sd_ut_inode = gfs2_lookup_simple(pn, buf);
+	if (IS_ERR(sdp->sd_ut_inode)) {
+		error = PTR_ERR(sdp->sd_ut_inode);
 		fs_err(sdp, "can't find local \"ut\" file: %d\n", error);
 		goto fail_sc_i;
 	}
 
 	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
-	error = gfs2_lookup_simple(pn, buf, &sdp->sd_qc_inode);
-	if (error) {
+	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
+	if (IS_ERR(sdp->sd_qc_inode)) {
+		error = PTR_ERR(sdp->sd_qc_inode);
 		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
 		goto fail_ut_i;
 	}