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| author | Theodore Ts'o <tytso@mit.edu> | 2009-04-27 22:48:48 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-04-27 22:48:48 -0400 |
| commit | c5ca7c7636fa689a9746b6032f83aa7fffec31c6 (patch) | |
| tree | eebbdd1d477b5062148ee61c9e1bf1d4da3e9e05 /fs/ext4 | |
| parent | 29fa89d088941d79765d60f22d5ccdd6b8696e11 (diff) | |
| download | linux-c5ca7c7636fa689a9746b6032f83aa7fffec31c6.tar.bz2 | |
ext4: Fallback to vmalloc if kmalloc can't allocate s_flex_groups array
For very large filesystems, the s_flex_groups array can get quite big.
For example, a filesystem that can be resized up to 16TB will have
8192 flex groups (assuming the default flex_bg size of 16), so the
array is 96k, which is *very* marginal for kmalloc(). On the other
hand, a 160GB filesystem without the resize_inode feature will only
require 960 bytes. So we try to allocate the array first using
kmalloc(), and if that fails, we'll try to use vmalloc() instead.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/super.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 2958f4e6f222..3f4475daa66d 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -20,6 +20,7 @@ #include <linux/string.h> #include <linux/fs.h> #include <linux/time.h> +#include <linux/vmalloc.h> #include <linux/jbd2.h> #include <linux/slab.h> #include <linux/init.h> @@ -586,7 +587,10 @@ 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); - kfree(sbi->s_flex_groups); + if (is_vmalloc_addr(sbi->s_flex_groups)) + vfree(sbi->s_flex_groups); + else + kfree(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); @@ -1620,6 +1624,7 @@ static int ext4_fill_flex_info(struct super_block *sb) ext4_group_t flex_group_count; ext4_group_t flex_group; int groups_per_flex = 0; + size_t size; int i; if (!sbi->s_es->s_log_groups_per_flex) { @@ -1634,8 +1639,13 @@ static int ext4_fill_flex_info(struct super_block *sb) flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) + ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) << EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex; - sbi->s_flex_groups = kzalloc(flex_group_count * - sizeof(struct flex_groups), GFP_KERNEL); + size = flex_group_count * sizeof(struct flex_groups); + sbi->s_flex_groups = kzalloc(size, GFP_KERNEL); + if (sbi->s_flex_groups == NULL) { + sbi->s_flex_groups = vmalloc(size); + if (sbi->s_flex_groups) + memset(sbi->s_flex_groups, 0, size); + } if (sbi->s_flex_groups == NULL) { printk(KERN_ERR "EXT4-fs: not enough memory for " "%u flex groups\n", flex_group_count); @@ -2842,6 +2852,12 @@ failed_mount4: sbi->s_journal = NULL; } failed_mount3: + if (sbi->s_flex_groups) { + if (is_vmalloc_addr(sbi->s_flex_groups)) + vfree(sbi->s_flex_groups); + else + kfree(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); |