ext4: introduce ext4_kvmalloc(), ext4_kzalloc(), and ext4_kvfree()

Introduce new helper functions which try kmalloc, and then fall back
to vmalloc if necessary, and use them for allocating and deallocating
s_flex_groups.

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

2 files changed, 39 insertions, 18 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ba2009b49a55..db9feadf53a0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1874,6 +1874,9 @@ extern int ext4_group_extend(struct super_block *sb,
                                 ext4_fsblk_t n_blocks_count);
 
 /* super.c */
+extern void *ext4_kvmalloc(size_t size, gfp_t flags);
+extern void *ext4_kvzalloc(size_t size, gfp_t flags);
+extern void ext4_kvfree(void *ptr);
 extern void __ext4_error(struct super_block *, const char *, unsigned int,
                          const char *, ...)
         __attribute__ ((format (printf, 4, 5)));
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cfe9f39c4ba2..658f5864e9cf 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -110,6 +110,35 @@ static struct file_system_type ext3_fs_type = {
 #define IS_EXT3_SB(sb) (0)
 #endif
 
+void *ext4_kvmalloc(size_t size, gfp_t flags)
+{
+        void *ret;
+
+        ret = kmalloc(size, flags);
+        if (!ret)
+                ret = __vmalloc(size, flags, PAGE_KERNEL);
+        return ret;
+}
+
+void *ext4_kvzalloc(size_t size, gfp_t flags)
+{
+        void *ret;
+
+        ret = kmalloc(size, flags);
+        if (!ret)
+                ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
+        return ret;
+}
+
+void ext4_kvfree(void *ptr)
+{
+        if (is_vmalloc_addr(ptr))
+                vfree(ptr);
+        else
+                kfree(ptr);
+
+}
+
 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
                                struct ext4_group_desc *bg)
 {
@@ -791,10 +820,7 @@ static void ext4_put_super(struct super_block *sb)
         for (i = 0; i < sbi->s_gdb_count; i++)
                 brelse(sbi->s_group_desc[i]);
         kfree(sbi->s_group_desc);
-        if (is_vmalloc_addr(sbi->s_flex_groups))
-                vfree(sbi->s_flex_groups);
-        else
-                kfree(sbi->s_flex_groups);
+        ext4_kvfree(sbi->s_flex_groups);
         percpu_counter_destroy(&sbi->s_freeblocks_counter);
         percpu_counter_destroy(&sbi->s_freeinodes_counter);
         percpu_counter_destroy(&sbi->s_dirs_counter);
@@ -1977,15 +2003,11 @@ static int ext4_fill_flex_info(struct super_block *sb)
                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
         size = flex_group_count * sizeof(struct flex_groups);
-        sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
+        sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
         if (sbi->s_flex_groups == NULL) {
-                sbi->s_flex_groups = vzalloc(size);
-                if (sbi->s_flex_groups == NULL) {
-                        ext4_msg(sb, KERN_ERR,
-                                 "not enough memory for %u flex groups",
-                                 flex_group_count);
-                        goto failed;
-                }
+                ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
+                         flex_group_count);
+                goto failed;
         }
 
         for (i = 0; i < sbi->s_groups_count; i++) {
@@ -3750,12 +3772,8 @@ failed_mount_wq:
         }
 failed_mount3:
         del_timer(&sbi->s_err_report);
-        if (sbi->s_flex_groups) {
-                if (is_vmalloc_addr(sbi->s_flex_groups))
-                        vfree(sbi->s_flex_groups);
-                else
-                        kfree(sbi->s_flex_groups);
-        }
+        if (sbi->s_flex_groups)
+                ext4_kvfree(sbi->s_flex_groups);
         percpu_counter_destroy(&sbi->s_freeblocks_counter);
         percpu_counter_destroy(&sbi->s_freeinodes_counter);
         percpu_counter_destroy(&sbi->s_dirs_counter);