From: Mingming Cao Subject: Re: [patch 2/2] i_version update - ext4 part Date: Tue, 29 May 2007 12:44:13 -0700 Message-ID: <1180467854.4204.15.camel@localhost.localdomain> References: <46570E16.5040006@bull.net> Reply-To: cmm@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, nfsv4@linux-nfs.org, linux-fsdevel@vger.kernel.org To: jean-noel.cordenner@bull.net Return-path: In-Reply-To: <46570E16.5040006@bull.net> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Fri, 2007-05-25 at 18:25 +0200, Jean noel Cordenner wrote: > The patch is on top of the ext4 tree: > http://repo.or.cz/w/ext4-patch-queue.git > > In this part, the i_version counter is stored into 2 32bit fields of > the ext4_inode structure osd1.linux1.l_i_version and i_version_hi. > > I included the ext4_expand_inode_extra_isize patch, which does part of > the job, checking if there is enough room for extra fields in the inode > (i_version_hi). The other patch increments the counter on inode > modifications and set it on inode creation. > plain text document attachment (i_version_update_ext4) > This patch is on top of i_version_update_vfs. > The i_version field of the inode is set on inode creation and incremented when > the inode is being modified. > I am a little bit confused about the two patches. It appears in the ext4_expand_inode_extra_isize patch by Kalpak, there a new 64 bit i_fs_version field is added to ext4 inode structure for inode versioning support. read/store of this counter are properly handled, but missing the inode versioning counter update. But later in the second patch by Jean Noel, he re-used the VFS inode- >i_version for ext4 inode versioning, the counter is being updated every time the file is being changed. To me, i_fs_version and inode_version are the same thing, right? Shouldn't we choose one(I assume inode i_version?), and combine these two patch together? How about split the inode versioning part from the ext4_expand_inode_extra_isize patch(it does multiple things, and i_versioning doesn't longs there) and put it together with the rest of i_version update patches? BTW, how could NFS/user space to access the inode version counter? Thanks, Mingming > Signed-off-by: Jean Noel Cordenner > > Index: linux-2.6.22-rc2-ext4-1/fs/ext4/ialloc.c > =================================================================== > --- linux-2.6.22-rc2-ext4-1.orig/fs/ext4/ialloc.c 2007-05-25 18:05:28.000000000 +0200 > +++ linux-2.6.22-rc2-ext4-1/fs/ext4/ialloc.c 2007-05-25 18:05:40.000000000 +0200 > @@ -565,6 +565,7 @@ > inode->i_blocks = 0; > inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = > ext4_current_time(inode); > + inode->i_version = 1; > > memset(ei->i_data, 0, sizeof(ei->i_data)); > ei->i_dir_start_lookup = 0; > Index: linux-2.6.22-rc2-ext4-1/fs/ext4/inode.c > =================================================================== > --- linux-2.6.22-rc2-ext4-1.orig/fs/ext4/inode.c 2007-05-25 18:05:28.000000000 +0200 > +++ linux-2.6.22-rc2-ext4-1/fs/ext4/inode.c 2007-05-25 18:05:40.000000000 +0200 > @@ -3082,6 +3082,7 @@ > { > int err = 0; > > + inode->i_version++; > /* the do_update_inode consumes one bh->b_count */ > get_bh(iloc->bh); > > Index: linux-2.6.22-rc2-ext4-1/fs/ext4/super.c > =================================================================== > --- linux-2.6.22-rc2-ext4-1.orig/fs/ext4/super.c 2007-05-25 18:05:28.000000000 +0200 > +++ linux-2.6.22-rc2-ext4-1/fs/ext4/super.c 2007-05-25 18:05:40.000000000 +0200 > @@ -2839,8 +2839,8 @@ > i_size_write(inode, off+len-towrite); > EXT4_I(inode)->i_disksize = inode->i_size; > } > - inode->i_version++; > inode->i_mtime = inode->i_ctime = CURRENT_TIME; > + inode->i_version = 1; > ext4_mark_inode_dirty(handle, inode); > mutex_unlock(&inode->i_mutex); > return len - towrite;