On Mon, 2006-11-06 at 15:50 -0600, Eric Sandeen wrote: > The inode diet patches first did this to generic_fillattr(): > > - stat->blksize = inode->i_blksize; > + stat->blksize = PAGE_CACHE_SIZE; > > but by 2.6.19-rc3 this was changed again: > > - stat->blksize = PAGE_CACHE_SIZE; > + stat->blksize = (1 << inode->i_blkbits); > > I can't find for sure why this was done; perhaps because it exposed a bug > in cifs[1] Steve has fixed the bug in cifs_readdir(). > However, if we are going to pick a default for generic_fillattr, it should probably > be what most filesystems were using before, and let filesystems which need something > else re-set it to according to their needs. As it stands today, doing readdirs and > the like in block-sized chunks rather than page sized will probably not be the > best thing for performance. I agree. > > so I would propose the following patch to make PAGE_CACHE_SIZE the default (again), > and let filesystems which need something -else- do that on their own. > > [1] http://lists.samba.org/archive/linux-cifs-client/2006-September/001481.html > > Thanks, > -Eric > > Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> > > --- linux.orig/fs/stat.c 2006-11-05 23:27:04.962482569 -0600 > +++ linux/fs/stat.c 2006-11-05 23:27:29.394396050 -0600 > @@ -33,7 +33,7 @@ > stat->ctime = inode->i_ctime; > stat->size = i_size_read(inode); > stat->blocks = inode->i_blocks; > - stat->blksize = (1 << inode->i_blkbits); > + stat->blksize = PAGE_CACHE_SIZE; > } > > EXPORT_SYMBOL(generic_fillattr); Looks good. Since cifs is affected by this patch, I propose that cifs explicitly set stat->blksize: CIFS: Explicitly set stat->blksize CIFS may perform I/O over the network in larger chunks than the page size, so it should explicitly set stat->blksize to ensure optimal I/O bandwidth Signed-off-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx> diff -Nurp linux.orig/fs/cifs/inode.c linux/fs/cifs/inode.c --- linux.orig/fs/cifs/inode.c 2006-11-03 13:44:04.000000000 -0600 +++ linux/fs/cifs/inode.c 2006-11-06 16:11:21.000000000 -0600 @@ -1089,8 +1089,10 @@ int cifs_getattr(struct vfsmount *mnt, s struct kstat *stat) { int err = cifs_revalidate(dentry); - if (!err) + if (!err) { generic_fillattr(dentry->d_inode, stat); + stat->blksize = CIFS_MAX_MSGSIZE; + } return err; } -- David Kleikamp IBM Linux Technology Center - 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
