ext4: factor out ext4_group_desc_init() and ext4_group_desc_free()

Factor out ext4_group_desc_init() and ext4_group_desc_free(). No
functional change.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220916141527.1012715-12-yanaijie@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ee0ca696c05fb5f68ef06afe930557bc41f0004a..1057149e08260f5ca0e50c1549d467ca766f9a56 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4720,9 +4720,89 @@ static int ext4_geometry_check(struct super_block *sb,
        return 0;
 }
 
+static void ext4_group_desc_free(struct ext4_sb_info *sbi)
+{
+       struct buffer_head **group_desc;
+       int i;
+
+       rcu_read_lock();
+       group_desc = rcu_dereference(sbi->s_group_desc);
+       for (i = 0; i < sbi->s_gdb_count; i++)
+               brelse(group_desc[i]);
+       kvfree(group_desc);
+       rcu_read_unlock();
+}
+
+static int ext4_group_desc_init(struct super_block *sb,
+                               struct ext4_super_block *es,
+                               ext4_fsblk_t logical_sb_block,
+                               ext4_group_t *first_not_zeroed)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       unsigned int db_count;
+       ext4_fsblk_t block;
+       int ret;
+       int i;
+
+       db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
+                  EXT4_DESC_PER_BLOCK(sb);
+       if (ext4_has_feature_meta_bg(sb)) {
+               if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
+                       ext4_msg(sb, KERN_WARNING,
+                                "first meta block group too large: %u "
+                                "(group descriptor block count %u)",
+                                le32_to_cpu(es->s_first_meta_bg), db_count);
+                       return -EINVAL;
+               }
+       }
+       rcu_assign_pointer(sbi->s_group_desc,
+                          kvmalloc_array(db_count,
+                                         sizeof(struct buffer_head *),
+                                         GFP_KERNEL));
+       if (sbi->s_group_desc == NULL) {
+               ext4_msg(sb, KERN_ERR, "not enough memory");
+               return -ENOMEM;
+       }
+
+       bgl_lock_init(sbi->s_blockgroup_lock);
+
+       /* Pre-read the descriptors into the buffer cache */
+       for (i = 0; i < db_count; i++) {
+               block = descriptor_loc(sb, logical_sb_block, i);
+               ext4_sb_breadahead_unmovable(sb, block);
+       }
+
+       for (i = 0; i < db_count; i++) {
+               struct buffer_head *bh;
+
+               block = descriptor_loc(sb, logical_sb_block, i);
+               bh = ext4_sb_bread_unmovable(sb, block);
+               if (IS_ERR(bh)) {
+                       ext4_msg(sb, KERN_ERR,
+                              "can't read group descriptor %d", i);
+                       sbi->s_gdb_count = i;
+                       ret = PTR_ERR(bh);
+                       goto out;
+               }
+               rcu_read_lock();
+               rcu_dereference(sbi->s_group_desc)[i] = bh;
+               rcu_read_unlock();
+       }
+       sbi->s_gdb_count = db_count;
+       if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
+               ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
+               ret = -EFSCORRUPTED;
+               goto out;
+       }
+       return 0;
+out:
+       ext4_group_desc_free(sbi);
+       return ret;
+}
+
 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
 {
-       struct buffer_head *bh, **group_desc;
+       struct buffer_head *bh;
        struct ext4_super_block *es = NULL;
        struct ext4_sb_info *sbi = EXT4_SB(sb);
        struct flex_groups **flex_groups;
@@ -4732,7 +4812,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
        struct inode *root;
        int ret = -ENOMEM;
        int blocksize;
-       unsigned int db_count;
        unsigned int i;
        int needs_recovery, has_huge_files;
        int err = 0;
@@ -5026,57 +5105,9 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
        if (ext4_geometry_check(sb, es))
                goto failed_mount;
 
-       db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
-                  EXT4_DESC_PER_BLOCK(sb);
-       if (ext4_has_feature_meta_bg(sb)) {
-               if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
-                       ext4_msg(sb, KERN_WARNING,
-                                "first meta block group too large: %u "
-                                "(group descriptor block count %u)",
-                                le32_to_cpu(es->s_first_meta_bg), db_count);
-                       goto failed_mount;
-               }
-       }
-       rcu_assign_pointer(sbi->s_group_desc,
-                          kvmalloc_array(db_count,
-                                         sizeof(struct buffer_head *),
-                                         GFP_KERNEL));
-       if (sbi->s_group_desc == NULL) {
-               ext4_msg(sb, KERN_ERR, "not enough memory");
-               ret = -ENOMEM;
+       err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
+       if (err)
                goto failed_mount;
-       }
-
-       bgl_lock_init(sbi->s_blockgroup_lock);
-
-       /* Pre-read the descriptors into the buffer cache */
-       for (i = 0; i < db_count; i++) {
-               block = descriptor_loc(sb, logical_sb_block, i);
-               ext4_sb_breadahead_unmovable(sb, block);
-       }
-
-       for (i = 0; i < db_count; i++) {
-               struct buffer_head *bh;
-
-               block = descriptor_loc(sb, logical_sb_block, i);
-               bh = ext4_sb_bread_unmovable(sb, block);
-               if (IS_ERR(bh)) {
-                       ext4_msg(sb, KERN_ERR,
-                              "can't read group descriptor %d", i);
-                       db_count = i;
-                       ret = PTR_ERR(bh);
-                       goto failed_mount2;
-               }
-               rcu_read_lock();
-               rcu_dereference(sbi->s_group_desc)[i] = bh;
-               rcu_read_unlock();
-       }
-       sbi->s_gdb_count = db_count;
-       if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
-               ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
-               ret = -EFSCORRUPTED;
-               goto failed_mount2;
-       }
 
        timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
        spin_lock_init(&sbi->s_error_lock);
@@ -5520,13 +5551,7 @@ failed_mount3:
        flush_work(&sbi->s_error_work);
        del_timer_sync(&sbi->s_err_report);
        ext4_stop_mmpd(sbi);
-failed_mount2:
-       rcu_read_lock();
-       group_desc = rcu_dereference(sbi->s_group_desc);
-       for (i = 0; i < db_count; i++)
-               brelse(group_desc[i]);
-       kvfree(group_desc);
-       rcu_read_unlock();
+       ext4_group_desc_free(sbi);
 failed_mount:
        if (sbi->s_chksum_driver)
                crypto_free_shash(sbi->s_chksum_driver);