Messages in this thread Patch in this message | | | Subject | [PATCH] clean up OCFS2 nlink handling | From | Dave Hansen <> | Date | Fri, 04 Aug 2006 14:01:32 -0700 |
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On Wed, 2006-08-02 at 17:20 -0700, Mark Fasheh wrote: > > - saved_nlink = inode->i_nlink; > > - if (S_ISDIR(inode->i_mode)) > > - inode->i_nlink = 0; > > - else > > - inode->i_nlink--; > > - > > status = ocfs2_request_unlink_vote(inode, dentry, > > (unsigned int) inode->i_nlink); > The network request above needs to send what the new nlink will be set to. > This is so that the other nodes which have an interest in the inode can > determine whether the will need to do orphan processing on their last iput. > > Really what they do is just compare against zero and mark the inode with a > flag indicating that it may have been orphaned. So we could just pass the > result of inode_is_unlinkable(), but I'd rather preserve the behavior that > we have today. > > The ugly method is: > > - status = ocfs2_request_unlink_vote(inode, dentry, > - (unsigned int) inode->i_nlink); > + status = ocfs2_request_unlink_vote(inode, dentry, > + S_ISDIR(inode->i_mode) && inode->i_nlink == 2 ? 0 : inode->i_nlink - 1); > > Better yet, we could store the result of the evaluation in a temporary > variable and pass that through to the request function.
OK, I hope this does it.
-- Dave
OCFS2 does some operations on i_nlink, then reverts them if some of its operations fail to complete. This does not fit in well with the inode_drop_nlink() logic where we expect i_nlink to stay at zero once it gets there.
So, delay all of the nlink operations until we're sure that the operations have completed. Also, introduce a small helper to check whether an inode has proper "unlinkable" i_nlink counts no matter whether it is a directory or regular inode.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com> ---
lxc-dave/fs/ocfs2/namei.c | 50 lxc-dave/fs/ocfs2/namei.c.orig | 2268 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 2294 insertions(+), 24 deletions(-)
diff -puN fs/ocfs2/namei.c~Re-_PATCH_04_28_OCFS2_is_screwy fs/ocfs2/namei.c --- lxc/fs/ocfs2/namei.c~Re-_PATCH_04_28_OCFS2_is_screwy 2006-08-04 13:53:36.000000000 -0700 +++ lxc-dave/fs/ocfs2/namei.c 2006-08-04 13:59:15.000000000 -0700 @@ -744,11 +744,23 @@ bail: return err; } +static inline inode_is_unlinkable(struct inode *inode) +{ + if (S_ISDIR(inode->i_mode)) { + if (inode->i_nlink == 2) + return 1; + return 0; + } + + if (inode->i_nlink == 1) + return 1; + return 0; +} + static int ocfs2_unlink(struct inode *dir, struct dentry *dentry) { int status; - unsigned int saved_nlink = 0; struct inode *inode = dentry->d_inode; struct ocfs2_super *osb = OCFS2_SB(dir->i_sb); u64 blkno; @@ -760,6 +772,7 @@ static int ocfs2_unlink(struct inode *di struct buffer_head *dirent_bh = NULL; char orphan_name[OCFS2_ORPHAN_NAMELEN + 1]; struct buffer_head *orphan_entry_bh = NULL; + unsigned int future_nlink; mlog_entry("(0x%p, 0x%p, '%.*s')\n", dir, dentry, dentry->d_name.len, dentry->d_name.name); @@ -823,18 +836,11 @@ static int ocfs2_unlink(struct inode *di } } - /* There are still a few steps left until we can consider the - * unlink to have succeeded. Save off nlink here before - * modification so we can set it back in case we hit an issue - * before commit. */ - saved_nlink = inode->i_nlink; - if (S_ISDIR(inode->i_mode)) - inode->i_nlink = 0; + if (S_ISDIR(inode->i_mode) && (inode->i_nlink == 2)) + future_nlink = 0; else - inode->i_nlink--; - - status = ocfs2_request_unlink_vote(inode, dentry, - (unsigned int) inode->i_nlink); + future_nlink = inode->i_nlink - 1; + status = ocfs2_request_unlink_vote(inode, dentry, future_nlink); if (status < 0) { /* This vote should succeed under all normal * circumstances. */ @@ -842,7 +848,7 @@ static int ocfs2_unlink(struct inode *di goto leave; } - if (!inode->i_nlink) { + if (inode_is_unlinkable(inode)) { status = ocfs2_prepare_orphan_dir(osb, handle, inode, orphan_name, &orphan_entry_bh); @@ -869,7 +875,7 @@ static int ocfs2_unlink(struct inode *di fe = (struct ocfs2_dinode *) fe_bh->b_data; - if (!inode->i_nlink) { + if (inode_is_unlinkable(inode)) { status = ocfs2_orphan_add(osb, handle, inode, fe, orphan_name, orphan_entry_bh); if (status < 0) { @@ -885,10 +891,10 @@ static int ocfs2_unlink(struct inode *di goto leave; } - /* We can set nlink on the dinode now. clear the saved version - * so that it doesn't get set later. */ + if (S_ISDIR(inode->i_mode)) + inode_drop_nlink(inode); + inode_drop_nlink(inode); fe->i_links_count = cpu_to_le16(inode->i_nlink); - saved_nlink = 0; status = ocfs2_journal_dirty(handle, fe_bh); if (status < 0) { @@ -897,19 +903,15 @@ static int ocfs2_unlink(struct inode *di } if (S_ISDIR(inode->i_mode)) { - dir->i_nlink--; status = ocfs2_mark_inode_dirty(handle, dir, parent_node_bh); - if (status < 0) { + if (status < 0) mlog_errno(status); - inc_nlink(dir); - } + else + inode_drop_nlink(dir); } leave: - if (status < 0 && saved_nlink) - inode->i_nlink = saved_nlink; - if (handle) ocfs2_commit_trans(handle); - 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/
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