gfs2_grow fails to grow a filesystem with less than 3 rgrps

Hi,

There's a problem with gfs2-utils whereby some of the utils can't handle a small file system with one or two rgrps. The biggest offender is gfs2_grow: you can't successfully gfs2_grow a file system that is so small that it has only one resource group. Also, "gfs2_edit savemeta" can't save it.

This patch is designed to remedy the problem by
creating a generic rgrp_size function in libgfs2
that calculates the size rather than judging its
distance from the previous rgrp.

Testing results (today's gfs2_grow versus patched):

# gfs2_grow /mnt/gfs2
Segmentation fault (core dumped)
# ./gfs2_grow /mnt/gfs2
FS: Mount Point: /mnt/gfs2
FS: Device:      /dev/mapper/vg_gfs2-lv_gfs2
FS: Size:        127997 (0x1f3fd)
FS: RG size:     127980 (0x1f3ec)
DEV: Size:       256000 (0x3e800)
The file system grew by 500MB.
gfs2_grow complete.

Regards,

Bob Peterson
Red Hat File Systems
--

 gfs2/edit/savemeta.c       |    6 ++----
 gfs2/libgfs2/fs_geometry.c |    6 +++---
 gfs2/libgfs2/libgfs2.h     |    5 +++++
 gfs2/libgfs2/super.c       |    4 ++--
 gfs2/mkfs/main_grow.c      |   27 +++++++++------------------
 5 files changed, 21 insertions(+), 27 deletions(-)

gfs2/edit/savemeta.c +2 -4

index 9e5d111..31af23d 100644
@@ -637,7 +637,7 @@ void savemeta(char *out_fn, int saveoption, int gziplevel)
 	int rgcount;
 	uint64_t jindex_block;
 	struct gfs2_buffer_head *lbh;
-	struct rgrp_tree *last_rgd, *prev_rgd;
+	struct rgrp_tree *last_rgd;
 	struct metafd mfd;
 
 	slow = (saveoption == 1);

@@ -715,9 +715,7 @@ void savemeta(char *out_fn, int saveoption, int gziplevel)
 		n = osi_last(&sbd.rgtree);
 		last_rgd = (struct rgrp_tree *)n;
 		n = osi_prev(n);
-		prev_rgd = (struct rgrp_tree *)n;
-		fssize = last_rgd->ri.ri_addr +
-			(last_rgd->ri.ri_addr - prev_rgd->ri.ri_addr);
+		fssize = last_rgd->ri.ri_addr + rgrp_size(last_rgd);
 		last_fs_block = fssize;
 		fssize *= sbd.bsize;
 		printf("Done. File system size: %s\n\n",

gfs2/libgfs2/fs_geometry.c +3 -3

index 2b70f11..130331a 100644
@@ -80,8 +80,8 @@ void compute_rgrp_layout(struct gfs2_sbd *sdp, struct osi_root *rgtree,
 	struct device *dev;
 	struct rgrp_tree *rl, *rlast = NULL, *rlast2 = NULL;
 	struct osi_node *n, *next = NULL;
-	unsigned int rgrp = 0, nrgrp;
-	uint64_t rglength, rgaddr;
+	unsigned int rgrp = 0, nrgrp, rglength;
+	uint64_t rgaddr;
 
 	sdp->new_rgrps = 0;
 	dev = &sdp->device;

@@ -113,7 +113,7 @@ void compute_rgrp_layout(struct gfs2_sbd *sdp, struct osi_root *rgtree,
 			rlast = rl;
 		}
 		rlast->start = rlast->ri.ri_addr;
-		rglength = rlast->ri.ri_addr - rlast2->ri.ri_addr;
+		rglength = rgrp_size(rlast);
 		rlast->length = rglength;
 		old_length = rlast->ri.ri_addr + rglength;
 		new_chunk = dev->length - old_length;

gfs2/libgfs2/libgfs2.h +5 -0

index 53df6cd..77dfc29 100644
@@ -708,6 +708,11 @@ extern void gfs2_rgrp_relse(struct rgrp_tree *rgd);
 extern struct rgrp_tree *rgrp_insert(struct osi_root *rgtree,
 				     uint64_t rgblock);
 extern void gfs2_rgrp_free(struct osi_root *rgrp_tree);
+/* figure out the size of the given resource group, in blocks */
+static inline unsigned int rgrp_size(struct rgrp_tree *rgrp)
+{
+	return rgrp->ri.ri_data + rgrp->ri.ri_length;
+}
 
 /* structures.c */
 extern int build_master(struct gfs2_sbd *sdp);

gfs2/libgfs2/super.c +2 -2

index c354b07..c844287 100644
@@ -194,7 +194,7 @@ int rindex_read(struct gfs2_sbd *sdp, int fd, int *count1, int *sane)
 					*sane = 0;
 			}
 			prev_length = rgd->start - prev_rgd->start;
-			prev_rgd->length = prev_length;
+			prev_rgd->length = rgrp_size(prev_rgd);
 		}
 
 		if(gfs2_compute_bitstructs(sdp, rgd))

@@ -204,7 +204,7 @@ int rindex_read(struct gfs2_sbd *sdp, int fd, int *count1, int *sane)
 		prev_rgd = rgd;
 	}
 	if (prev_rgd)
-		prev_rgd->length = prev_length;
+		prev_rgd->length = rgrp_size(prev_rgd);
 	return 0;
 }
 

gfs2/mkfs/main_grow.c +9 -18

index dc092ee..7a32d7e 100644
@@ -122,23 +122,6 @@ static void decode_arguments(int argc, char *argv[], struct gfs2_sbd *sdp)
 }
 
 /**
- * figure_out_rgsize
- */
-static void figure_out_rgsize(struct gfs2_sbd *sdp, unsigned int *orgsize)
-{
-	struct osi_node *n = osi_first(&sdp->rgtree), *next = NULL;
-	struct rgrp_tree *r1, *r2;
-
-	sdp->rgsize = GFS2_DEFAULT_RGSIZE;
-	next = osi_next(n);
-	r1 = (struct rgrp_tree *)next;
-	next = osi_next(next);
-	r2 = (struct rgrp_tree *)next;
-
-	*orgsize = r2->ri.ri_addr - r1->ri.ri_addr;
-}
-
-/**
  * filesystem_size - Calculate the size of the filesystem
  *
  * Reads the lists of resource groups in order to

@@ -324,6 +307,7 @@ main_grow(int argc, char *argv[])
 
 	while ((argc - optind) > 0) {
 		int sane;
+		struct rgrp_tree *last_rgrp;
 
 		sdp->path_name = argv[optind++];
 		sdp->path_fd = open(sdp->path_name, O_RDONLY | O_CLOEXEC);

@@ -391,7 +375,13 @@ main_grow(int argc, char *argv[])
 		/* the existing RGs, and only write to the index at EOF.    */
 		ri_update(sdp, rindex_fd, &rgcount, &sane);
 		fssize = filesystem_size(sdp);
-		figure_out_rgsize(sdp, &rgsize);
+		if (!sdp->rgtree.osi_node) {
+			log_err(_("Error: No resource groups found.\n"));
+			goto out;
+		}
+		last_rgrp = (struct rgrp_tree *)osi_last(&sdp->rgtree);
+		sdp->rgsize = GFS2_DEFAULT_RGSIZE;
+		rgsize = rgrp_size(last_rgrp);
 		fsgrowth = ((sdp->device.length - fssize) * sdp->bsize);
 		if (fsgrowth < rgsize * sdp->bsize) {
 			log_err( _("Error: The device has grown by less than "

@@ -409,6 +399,7 @@ main_grow(int argc, char *argv[])
 			initialize_new_portion(sdp, &old_rg_count);
 			fix_rindex(sdp, rindex_fd, old_rg_count);
 		}
+	out:
 		/* Delete the remaining RGs from the rglist */
 		gfs2_rgrp_free(&sdp->rgtree);
 		close(rindex_fd);