[PATCH 20/25] Unionfs: add un/likely conditionals on rename ops

Erez Zadok
2007-09-26T03:33:46Z

fs/unionfs/rename.c | 96 +++++++++++++++++++++++++-------------------------
1 files changed, 48 insertions(+), 48 deletions(-)

diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c
index 7b8fe39..92c4515 100644
--- a/fs/unionfs/rename.c
+++ b/fs/unionfs/rename.c
@@ -39,7 +39,7 @@ static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
create_parents(new_dentry->d_parent->d_inode,
new_dentry, new_dentry->d_name.name,
bindex);
- if (IS_ERR(lower_new_dentry)) {
+ if (unlikely(IS_ERR(lower_new_dentry))) {
printk(KERN_DEBUG "unionfs: error creating directory "
"tree for rename, bindex = %d, err = %ld\n",
bindex, PTR_ERR(lower_new_dentry));
@@ -50,7 +50,7 @@ static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,

wh_name = alloc_whname(new_dentry->d_name.name,
new_dentry->d_name.len);
- if (IS_ERR(wh_name)) {
+ if (unlikely(IS_ERR(wh_name))) {
err = PTR_ERR(wh_name);
goto out;
}
@@ -58,14 +58,14 @@ static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
lower_wh_dentry = lookup_one_len(wh_name, lower_new_dentry->d_parent,
new_dentry->d_name.len +
UNIONFS_WHLEN);
- if (IS_ERR(lower_wh_dentry)) {
+ if (unlikely(IS_ERR(lower_wh_dentry))) {
err = PTR_ERR(lower_wh_dentry);
goto out;
}

if (lower_wh_dentry->d_inode) {
/* get rid of the whiteout that is existing */
- if (lower_new_dentry->d_inode) {
+ if (unlikely(lower_new_dentry->d_inode)) {
printk(KERN_WARNING "unionfs: both a whiteout and a "
"dentry exist when doing a rename!\n");
err = -EIO;
@@ -81,7 +81,7 @@ static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,

dput(lower_wh_dentry);
unlock_dir(lower_wh_dir_dentry);
- if (err)
+ if (unlikely(err))
goto out;
} else
dput(lower_wh_dentry);
@@ -93,7 +93,7 @@ static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);

err = is_robranch_super(old_dentry->d_sb, bindex);
- if (err)
+ if (unlikely(err))
goto out_unlock;

/*
@@ -105,14 +105,14 @@ static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
whname = alloc_whname(old_dentry->d_name.name,
old_dentry->d_name.len);
err = PTR_ERR(whname);
- if (IS_ERR(whname))
+ if (unlikely(IS_ERR(whname)))
goto out_unlock;
*wh_old = lookup_one_len(whname, lower_old_dir_dentry,
old_dentry->d_name.len +
UNIONFS_WHLEN);
kfree(whname);
err = PTR_ERR(*wh_old);
- if (IS_ERR(*wh_old)) {
+ if (unlikely(IS_ERR(*wh_old))) {
*wh_old = NULL;
goto out_unlock;
}
@@ -129,7 +129,7 @@ out_unlock:
dput(lower_old_dentry);

out:
- if (!err) {
+ if (likely(!err)) {
/* Fixup the new_dentry. */
if (bindex < dbstart(new_dentry))
set_dbstart(new_dentry, bindex);
@@ -174,8 +174,8 @@ static int do_unionfs_rename(struct inode *old_dir,
/* Rename source to destination. */
err = __unionfs_rename(old_dir, old_dentry, new_dir, new_dentry,
old_bstart, &wh_old);
- if (err) {
- if (!IS_COPYUP_ERR(err))
+ if (unlikely(err)) {
+ if (unlikely(!IS_COPYUP_ERR(err)))
goto out;
do_copyup = old_bstart - 1;
} else
@@ -190,7 +190,7 @@ static int do_unionfs_rename(struct inode *old_dir,
struct dentry *unlink_dir_dentry;

unlink_dentry = unionfs_lower_dentry_idx(new_dentry, bindex);
- if (!unlink_dentry)
+ if (unlikely(!unlink_dentry))
continue;

unlink_dir_dentry = lock_parent(unlink_dentry);
@@ -205,15 +205,15 @@ static int do_unionfs_rename(struct inode *old_dir,
unionfs_get_nlinks(new_dentry->d_parent->d_inode);

unlock_dir(unlink_dir_dentry);
- if (!err) {
+ if (likely(!err)) {
if (bindex != new_bstart) {
dput(unlink_dentry);
unionfs_set_lower_dentry_idx(new_dentry,
bindex, NULL);
}
- } else if (IS_COPYUP_ERR(err)) {
+ } else if (unlikely(IS_COPYUP_ERR(err))) {
do_copyup = bindex - 1;
- } else if (revert) {
+ } else if (unlikely(revert)) {
dput(wh_old);
goto revert;
}
@@ -231,7 +231,7 @@ static int do_unionfs_rename(struct inode *old_dir,
old_dentry->d_name.len,
NULL, old_dentry->d_inode->i_size);
/* if copyup failed, try next branch to the left */
- if (err)
+ if (unlikely(err))
continue;
dput(wh_old);
bwh_old = bindex;
@@ -245,7 +245,7 @@ static int do_unionfs_rename(struct inode *old_dir,
/* make it opaque */
if (S_ISDIR(old_dentry->d_inode->i_mode)) {
err = make_dir_opaque(old_dentry, dbstart(old_dentry));
- if (err)
+ if (unlikely(err))
goto revert;
}

@@ -254,10 +254,10 @@ static int do_unionfs_rename(struct inode *old_dir,
* (1) There is more than one underlying instance of source.
* (2) We did a copy_up
*/
- if ((old_bstart != old_bend) || (do_copyup != -1)) {
+ if (unlikely((old_bstart != old_bend) || (do_copyup != -1))) {
struct dentry *lower_parent;
struct nameidata nd;
- if (!wh_old || wh_old->d_inode || bwh_old < 0) {
+ if (unlikely(!wh_old || wh_old->d_inode || bwh_old < 0)) {
printk(KERN_ERR "unionfs: rename error "
"(wh_old=%p/%p bwh_old=%d)\n", wh_old,
(wh_old ? wh_old->d_inode : NULL), bwh_old);
@@ -265,13 +265,13 @@ static int do_unionfs_rename(struct inode *old_dir,
goto out;
}
err = init_lower_nd(&nd, LOOKUP_CREATE);
- if (err < 0)
+ if (unlikely(err < 0))
goto out;
lower_parent = lock_parent(wh_old);
local_err = vfs_create(lower_parent->d_inode, wh_old, S_IRUGO,
&nd);
unlock_dir(lower_parent);
- if (!local_err)
+ if (likely(!local_err))
set_dbopaque(old_dentry, bwh_old);
else {
/*
@@ -292,30 +292,30 @@ out:
revert:
/* Do revert here. */
local_err = unionfs_refresh_lower_dentry(new_dentry, old_bstart);
- if (local_err) {
+ if (unlikely(local_err)) {
printk(KERN_WARNING "unionfs: revert failed in rename: "
"the new refresh failed.\n");
eio = -EIO;
}

local_err = unionfs_refresh_lower_dentry(old_dentry, old_bstart);
- if (local_err) {
+ if (unlikely(local_err)) {
printk(KERN_WARNING "unionfs: revert failed in rename: "
"the old refresh failed.\n");
eio = -EIO;
goto revert_out;
}

- if (!unionfs_lower_dentry_idx(new_dentry, bindex) ||
- !unionfs_lower_dentry_idx(new_dentry, bindex)->d_inode) {
+ if (unlikely(!unionfs_lower_dentry_idx(new_dentry, bindex) ||
+ !unionfs_lower_dentry_idx(new_dentry, bindex)->d_inode)) {
printk(KERN_WARNING "unionfs: revert failed in rename: "
"the object disappeared from under us!\n");
eio = -EIO;
goto revert_out;
}

- if (unionfs_lower_dentry_idx(old_dentry, bindex) &&
- unionfs_lower_dentry_idx(old_dentry, bindex)->d_inode) {
+ if (unlikely(unionfs_lower_dentry_idx(old_dentry, bindex) &&
+ unionfs_lower_dentry_idx(old_dentry, bindex)->d_inode)) {
printk(KERN_WARNING "unionfs: revert failed in rename: "
"the object was created underneath us!\n");
eio = -EIO;
@@ -326,16 +326,16 @@ revert:
old_dir, old_dentry, old_bstart, NULL);

/* If we can't fix it, then we cop-out with -EIO. */
- if (local_err) {
+ if (unlikely(local_err)) {
printk(KERN_WARNING "unionfs: revert failed in rename!\n");
eio = -EIO;
}

local_err = unionfs_refresh_lower_dentry(new_dentry, bindex);
- if (local_err)
+ if (unlikely(local_err))
eio = -EIO;
local_err = unionfs_refresh_lower_dentry(old_dentry, bindex);
- if (local_err)
+ if (unlikely(local_err))
eio = -EIO;

revert_out:
@@ -351,7 +351,7 @@ static struct dentry *lookup_whiteout(struct dentry *dentry)
struct dentry *parent, *lower_parent, *wh_dentry;

whname = alloc_whname(dentry->d_name.name, dentry->d_name.len);
- if (IS_ERR(whname))
+ if (unlikely(IS_ERR(whname)))
return (void *)whname;

parent = dget_parent(dentry);
@@ -361,11 +361,11 @@ static struct dentry *lookup_whiteout(struct dentry *dentry)
wh_dentry = ERR_PTR(-ENOENT);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_parent = unionfs_lower_dentry_idx(parent, bindex);
- if (!lower_parent)
+ if (unlikely(!lower_parent))
continue;
wh_dentry = lookup_one_len(whname, lower_parent,
dentry->d_name.len + UNIONFS_WHLEN);
- if (IS_ERR(wh_dentry))
+ if (unlikely(IS_ERR(wh_dentry)))
continue;
if (wh_dentry->d_inode)
break;
@@ -389,10 +389,10 @@ static int may_rename_dir(struct dentry *dentry)
int err, bstart;

err = check_empty(dentry, NULL);
- if (err == -ENOTEMPTY) {
- if (is_robranch(dentry))
+ if (unlikely(err == -ENOTEMPTY)) {
+ if (unlikely(is_robranch(dentry)))
return -EXDEV;
- } else if (err)
+ } else if (likely(err))
return err;

bstart = dbstart(dentry);
@@ -402,7 +402,7 @@ static int may_rename_dir(struct dentry *dentry)
set_dbstart(dentry, bstart + 1);
err = check_empty(dentry, NULL);
set_dbstart(dentry, bstart);
- if (err == -ENOTEMPTY)
+ if (unlikely(err == -ENOTEMPTY))
err = -EXDEV;
return err;
}
@@ -416,12 +416,12 @@ int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
unionfs_read_lock(old_dentry->d_sb);
unionfs_double_lock_dentry(old_dentry, new_dentry);

- if (!__unionfs_d_revalidate_chain(old_dentry, NULL, false)) {
+ if (unlikely(!__unionfs_d_revalidate_chain(old_dentry, NULL, false))) {
err = -ESTALE;
goto out;
}
- if (!d_deleted(new_dentry) && new_dentry->d_inode &&
- !__unionfs_d_revalidate_chain(new_dentry, NULL, false)) {
+ if (unlikely(!d_deleted(new_dentry) && new_dentry->d_inode &&
+ !__unionfs_d_revalidate_chain(new_dentry, NULL, false))) {
err = -ESTALE;
goto out;
}
@@ -431,11 +431,11 @@ int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
else
err = may_rename_dir(old_dentry);

- if (err)
+ if (unlikely(err))
goto out;

err = unionfs_partial_lookup(new_dentry);
- if (err)
+ if (unlikely(err))
goto out;

/*
@@ -443,11 +443,11 @@ int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
* simply override it even if the whited-out dir is not empty.
*/
wh_dentry = lookup_whiteout(new_dentry);
- if (!IS_ERR(wh_dentry))
+ if (likely(!IS_ERR(wh_dentry)))
dput(wh_dentry);
else if (new_dentry->d_inode) {
- if (S_ISDIR(old_dentry->d_inode->i_mode) !=
- S_ISDIR(new_dentry->d_inode->i_mode)) {
+ if (unlikely(S_ISDIR(old_dentry->d_inode->i_mode) !=
+ S_ISDIR(new_dentry->d_inode->i_mode))) {
err = S_ISDIR(old_dentry->d_inode->i_mode) ?
-ENOTDIR : -EISDIR;
goto out;
@@ -457,7 +457,7 @@ int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct unionfs_dir_state *namelist;
/* check if this unionfs directory is empty or not */
err = check_empty(new_dentry, &namelist);
- if (err)
+ if (unlikely(err))
goto out;

if (!is_robranch(new_dentry))
@@ -467,13 +467,13 @@ int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,

free_rdstate(namelist);

- if (err)
+ if (unlikely(err))
goto out;
}
}
err = do_unionfs_rename(old_dir, old_dentry, new_dir, new_dentry);
out:
- if (err)
+ if (unlikely(err))
/* clear the new_dentry stuff created */
d_drop(new_dentry);
else {
--
1.5.2.2