On Wed, Oct 07, 2009 at 09:11:15PM +0800, Peter Staubach wrote:
> Wu Fengguang wrote:
> > It was introduced in 72cb77f4a5ac, and the several issues have been
> > addressed in generic writeback:
> > - out of order writeback (or interleaved concurrent writeback)
> > addressed by the per-bdi writeback and wait queue in balance_dirty_pages()
> > - sync livelocked by a fast dirtier
> > addressed by throttling all to-be-synced dirty inodes
> >
>
> I don't think that we can just remove this support. It is
> designed to reduce the effects from doing a stat(2) on a
> file which is being actively written to.
Ah OK.
> If we do remove it, then we will need to replace this patch
> with another. Trond and I hadn't quite finished discussing
> some aspects of that other patch... :-)
I noticed the i_mutex lock in nfs_getattr(). Do you mean that?
Thanks,
Fengguang
> > CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> > CC: Peter Staubach <staubach@xxxxxxxxxx>
> > CC: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> > Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
> > ---
> > fs/nfs/file.c | 9 ---------
> > fs/nfs/write.c | 11 -----------
> > include/linux/nfs_fs.h | 1 -
> > 3 files changed, 21 deletions(-)
> >
> > --- linux.orig/fs/nfs/file.c 2009-10-07 14:31:45.000000000 +0800
> > +++ linux/fs/nfs/file.c 2009-10-07 14:32:54.000000000 +0800
> > @@ -386,15 +386,6 @@ static int nfs_write_begin(struct file *
> > mapping->host->i_ino, len, (long long) pos);
> >
> > start:
> > - /*
> > - * Prevent starvation issues if someone is doing a consistency
> > - * sync-to-disk
> > - */
> > - ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
> > - nfs_wait_bit_killable, TASK_KILLABLE);
> > - if (ret)
> > - return ret;
> > -
> > page = grab_cache_page_write_begin(mapping, index, flags);
> > if (!page)
> > return -ENOMEM;
> > --- linux.orig/fs/nfs/write.c 2009-10-07 14:31:45.000000000 +0800
> > +++ linux/fs/nfs/write.c 2009-10-07 14:32:54.000000000 +0800
> > @@ -387,26 +387,15 @@ static int nfs_writepages_callback(struc
> > int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
> > {
> > struct inode *inode = mapping->host;
> > - unsigned long *bitlock = &NFS_I(inode)->flags;
> > struct nfs_pageio_descriptor pgio;
> > int err;
> >
> > - /* Stop dirtying of new pages while we sync */
> > - err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
> > - nfs_wait_bit_killable, TASK_KILLABLE);
> > - if (err)
> > - goto out_err;
> > -
> > nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
> >
> > nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
> > err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
> > nfs_pageio_complete(&pgio);
> >
> > - clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
> > - smp_mb__after_clear_bit();
> > - wake_up_bit(bitlock, NFS_INO_FLUSHING);
> > -
> > if (err < 0)
> > goto out_err;
> > err = pgio.pg_error;
> > --- linux.orig/include/linux/nfs_fs.h 2009-10-07 14:31:45.000000000 +0800
> > +++ linux/include/linux/nfs_fs.h 2009-10-07 14:32:54.000000000 +0800
> > @@ -208,7 +208,6 @@ struct nfs_inode {
> > #define NFS_INO_STALE (1) /* possible stale inode */
> > #define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
> > #define NFS_INO_MOUNTPOINT (3) /* inode is remote mountpoint */
> > -#define NFS_INO_FLUSHING (4) /* inode is flushing out data */
> > #define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */
> > #define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
