lkml.org 
[lkml]   [2008]   [Aug]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] make lock_super recursive to simulate BKL
* Linus Torvalds <torvalds@linux-foundation.org> [080819 18:23]:
>
>
> On Tue, 19 Aug 2008, Bart Trojanowski wrote:
> >
> > This fixes a regression introduced when BKL was removed from the
> > vfat driver in commit 8f5934278d1d86590244c2791b28f77d67466007.
>
> I agree that it's going to almost certainly fix the regression, but could
> you test the following patch instead as an alternative? I'd rather remove
> the broken recursive lockign than introduce it as an acceptable concept.

Looks good. I ran 10 parallel processes creating 1M files truncating
them, writing to them again and then deleting them. This patch fixes
the issue I ran into.

Signed-off-by: Bart Trojanowski <bart@jukie.net>

> ---
> fs/fat/inode.c | 10 +++-------
> 1 files changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index 6d266d7..80ff338 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -562,26 +562,23 @@ static int fat_write_inode(struct inode *inode, int wait)
> struct buffer_head *bh;
> struct msdos_dir_entry *raw_entry;
> loff_t i_pos;
> - int err = 0;
> + int err;
>
> retry:
> i_pos = MSDOS_I(inode)->i_pos;
> if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
> return 0;
>
> - lock_super(sb);
> bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
> if (!bh) {
> printk(KERN_ERR "FAT: unable to read inode block "
> "for updating (i_pos %lld)\n", i_pos);
> - err = -EIO;
> - goto out;
> + return -EIO;
> }
> spin_lock(&sbi->inode_hash_lock);
> if (i_pos != MSDOS_I(inode)->i_pos) {
> spin_unlock(&sbi->inode_hash_lock);
> brelse(bh);
> - unlock_super(sb);
> goto retry;
> }
>
> @@ -607,11 +604,10 @@ retry:
> }
> spin_unlock(&sbi->inode_hash_lock);
> mark_buffer_dirty(bh);
> + err = 0;
> if (wait)
> err = sync_dirty_buffer(bh);
> brelse(bh);
> -out:
> - unlock_super(sb);
> return err;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

--
WebSig: http://www.jukie.net/~bart/sig/


\
 
 \ /
  Last update: 2008-08-20 03:17    [W:0.050 / U:38.644 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site