resize2fs, libext2fs: fix bugs in sparse_super2 support

Fix resize2fs so that the location of the backup superblocks when the
sparse_super2 feature is enabled is properly set when growing the file
system from a single block group to larger file system sizes.

Also fix a bug where the block group summary statistics in some cases
when exapnding a sparse_super2 file system.

Finally, accurately calculate the file system metadata overhead of the
last block group in sparse_super2 file systems.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index 8714ff5095948c58de2dda918abeee94dd6ce62f..32f43210a23543c79dd5202fde95d5e60af1cb2d 100644 (file)
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -98,6 +98,7 @@ errcode_t ext2fs_initialize(const char *name, int flags,
        int             csum_flag;
        int             bigalloc_flag;
        int             io_flags;
+       int             has_bg;
        unsigned        reserved_inos;
        char            *buf = 0;
        char            c;
@@ -404,7 +405,19 @@ ipg_retry:
         * backup.
         */
        overhead = (int) (2 + fs->inode_blocks_per_group);
-       if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
+       has_bg = 0;
+       if (ext2fs_has_feature_sparse_super2(super)) {
+               /*
+                * We have to do this manually since
+                * super->s_backup_bgs hasn't been set up yet.
+                */
+               if (fs->group_desc_count == 2)
+                       has_bg = param->s_backup_bgs[0] != 0;
+               else
+                       has_bg = param->s_backup_bgs[1] != 0;
+       } else
+               has_bg = ext2fs_bg_has_super(fs, fs->group_desc_count - 1);
+       if (has_bg)
                overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
        rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) %
               super->s_blocks_per_group);

diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index 36da253fccfcf0bdd67aec3f8e263656da25b967..8d33e546fd74f67ede4aef6ff2dcb3a78a01fe26 100644 (file)
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -206,6 +206,10 @@ errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
                goto errout;
        print_resource_track(rfs, &rtrack, fs->io);
 
+       retval = clear_sparse_super2_last_group(rfs);
+       if (retval)
+               goto errout;
+
        init_resource_track(&rtrack, "calculate_summary_stats", fs->io);
        retval = ext2fs_calculate_summary_stats(rfs->new_fs);
        if (retval)
@@ -224,10 +228,6 @@ errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
                goto errout;
        print_resource_track(rfs, &rtrack, fs->io);
 
-       retval = clear_sparse_super2_last_group(rfs);
-       if (retval)
-               goto errout;
-
        retval = ext2fs_set_gdt_csum(rfs->new_fs);
        if (retval)
                goto errout;
@@ -698,7 +698,7 @@ errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
        blk64_t         old_numblocks, numblocks, adjblocks;
        unsigned long   i, j, old_desc_blocks;
        unsigned int    meta_bg, meta_bg_size;
-       int             has_super, csum_flag;
+       int             has_super, csum_flag, has_bg;
        unsigned long long new_inodes;  /* u64 to check for overflow */
        double          percent;
 
@@ -721,7 +721,19 @@ retry:
         */
        overhead = (int) (2 + fs->inode_blocks_per_group);
 
-       if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
+       has_bg = 0;
+       if (ext2fs_has_feature_sparse_super2(fs->super)) {
+               /*
+                * We have to do this manually since
+                * super->s_backup_bgs hasn't been set up yet.
+                */
+               if (fs->group_desc_count == 2)
+                       has_bg = fs->super->s_backup_bgs[0] != 0;
+               else
+                       has_bg = fs->super->s_backup_bgs[1] != 0;
+       } else
+               has_bg = ext2fs_bg_has_super(fs, fs->group_desc_count - 1);
+       if (has_bg)
                overhead += 1 + fs->desc_blocks +
                        fs->super->s_reserved_gdt_blocks;
 
@@ -843,10 +855,9 @@ retry:
                if (last_bg > old_last_bg) {
                        if (old_fs->group_desc_count == 1)
                                fs->super->s_backup_bgs[0] = 1;
-                       if (old_fs->group_desc_count == 1 &&
-                           fs->super->s_backup_bgs[0])
-                               fs->super->s_backup_bgs[0] = last_bg;
-                       else if (fs->super->s_backup_bgs[1])
+                       if ((old_fs->group_desc_count < 3 &&
+                            fs->group_desc_count > 2) ||
+                           fs->super->s_backup_bgs[1])
                                fs->super->s_backup_bgs[1] = last_bg;
                } else if (last_bg < old_last_bg) {
                        if (fs->super->s_backup_bgs[0] > last_bg)
@@ -2466,6 +2477,9 @@ static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs)
            fs->super->s_backup_bgs[1] == old_last_bg)
                return 0;
 
+       if (old_last_bg == 0)
+               return 0;
+
        retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, old_last_bg,
                                           &sb, &old_desc, NULL, &num);
        if (retval)