From 232530680290ba94ca37852ab10d9556ea28badf Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 8 Nov 2017 22:23:20 -0500 Subject: 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 Signed-off-by: Theodore Ts'o --- fs/ext4/ioctl.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'fs/ext4/ioctl.c') 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 #include #include +#include #include #include #include @@ -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); -- cgit v1.2.3