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| author | Theodore Ts'o <tytso@mit.edu> | 2017-11-09 06:23:20 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2017-11-09 06:23:20 +0300 |
| commit | 232530680290ba94ca37852ab10d9556ea28badf (patch) | |
| tree | cf23ba2b6c563adc685f3b9fee830ac7d202546c /fs/ext4/ioctl.c | |
| parent | d77147ff443b255d82c907a632c825b2cc610b10 (diff) | |
| download | linux-232530680290ba94ca37852ab10d9556ea28badf.tar.xz | |
ext4: improve smp scalability for inode generation
->s_next_generation is protected by s_next_gen_lock but its usage
pattern is very primitive. We don't actually need sequentially
increasing new generation numbers, so let's use prandom_u32() instead.
Reported-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ioctl.c')
| -rw-r--r-- | fs/ext4/ioctl.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 144bbda2b808..23a4766f6678 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -14,6 +14,7 @@ #include <linux/mount.h> #include <linux/file.h> #include <linux/quotaops.h> +#include <linux/random.h> #include <linux/uuid.h> #include <linux/uaccess.h> #include <linux/delay.h> @@ -98,7 +99,6 @@ static long swap_inode_boot_loader(struct super_block *sb, int err; struct inode *inode_bl; struct ext4_inode_info *ei_bl; - struct ext4_sb_info *sbi = EXT4_SB(sb); if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode)) return -EINVAL; @@ -157,10 +157,8 @@ static long swap_inode_boot_loader(struct super_block *sb, inode->i_ctime = inode_bl->i_ctime = current_time(inode); - spin_lock(&sbi->s_next_gen_lock); - inode->i_generation = sbi->s_next_generation++; - inode_bl->i_generation = sbi->s_next_generation++; - spin_unlock(&sbi->s_next_gen_lock); + inode->i_generation = prandom_u32(); + inode_bl->i_generation = prandom_u32(); ext4_discard_preallocations(inode); |