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Message-Id: <20200301215240.873899-46-viro@ZenIV.linux.org.uk>
Date: Sun, 1 Mar 2020 21:52:31 +0000
From: Al Viro <viro@...IV.linux.org.uk>
To: linux-fsdevel@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [RFC][PATCH v3 46/55] move follow_dotdot() and follow_dotdot_rcu() towards handle_dots()
From: Al Viro <viro@...iv.linux.org.uk>
pure move
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
fs/namei.c | 192 ++++++++++++++++++++++++++++++-------------------------------
1 file changed, 96 insertions(+), 96 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 20a2fc27dd87..1bfefb99cbca 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1363,70 +1363,6 @@ static inline int handle_mounts(struct nameidata *nd, struct dentry *dentry,
return ret;
}
-static int follow_dotdot_rcu(struct nameidata *nd)
-{
- struct dentry *parent = NULL;
- struct inode *inode = nd->inode;
- unsigned seq;
-
- while (1) {
- if (path_equal(&nd->path, &nd->root))
- break;
- if (nd->path.dentry != nd->path.mnt->mnt_root) {
- struct dentry *old = nd->path.dentry;
-
- parent = old->d_parent;
- inode = parent->d_inode;
- seq = read_seqcount_begin(&parent->d_seq);
- if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq)))
- return -ECHILD;
- if (unlikely(!path_connected(nd->path.mnt, parent)))
- return -ECHILD;
- break;
- } else {
- struct mount *mnt = real_mount(nd->path.mnt);
- struct mount *mparent = mnt->mnt_parent;
- struct dentry *mountpoint = mnt->mnt_mountpoint;
- struct inode *inode2 = mountpoint->d_inode;
- unsigned seq = read_seqcount_begin(&mountpoint->d_seq);
- if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
- return -ECHILD;
- if (&mparent->mnt == nd->path.mnt)
- break;
- if (unlikely(nd->flags & LOOKUP_NO_XDEV))
- return -ECHILD;
- /* we know that mountpoint was pinned */
- nd->path.dentry = mountpoint;
- nd->path.mnt = &mparent->mnt;
- inode = inode2;
- nd->seq = seq;
- }
- }
- if (unlikely(!parent)) {
- if (unlikely(nd->flags & LOOKUP_BENEATH))
- return -ECHILD;
- } else {
- nd->path.dentry = parent;
- nd->seq = seq;
- }
- while (unlikely(d_mountpoint(nd->path.dentry))) {
- struct mount *mounted;
- mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
- if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
- return -ECHILD;
- if (!mounted)
- break;
- if (unlikely(nd->flags & LOOKUP_NO_XDEV))
- return -ECHILD;
- nd->path.mnt = &mounted->mnt;
- nd->path.dentry = mounted->mnt.mnt_root;
- inode = nd->path.dentry->d_inode;
- nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
- }
- nd->inode = inode;
- return 0;
-}
-
/*
* Skip to top of mountpoint pile in refwalk mode for follow_dotdot()
*/
@@ -1443,38 +1379,6 @@ static void follow_mount(struct path *path)
}
}
-static int follow_dotdot(struct nameidata *nd)
-{
- struct dentry *parent = NULL;
- while (1) {
- if (path_equal(&nd->path, &nd->root))
- break;
- if (nd->path.dentry != nd->path.mnt->mnt_root) {
- /* rare case of legitimate dget_parent()... */
- parent = dget_parent(nd->path.dentry);
- if (unlikely(!path_connected(nd->path.mnt, parent))) {
- dput(parent);
- return -ENOENT;
- }
- break;
- }
- if (!follow_up(&nd->path))
- break;
- if (unlikely(nd->flags & LOOKUP_NO_XDEV))
- return -EXDEV;
- }
- if (unlikely(!parent)) {
- if (unlikely(nd->flags & LOOKUP_BENEATH))
- return -EXDEV;
- } else {
- dput(nd->path.dentry);
- nd->path.dentry = parent;
- }
- follow_mount(&nd->path);
- nd->inode = nd->path.dentry->d_inode;
- return 0;
-}
-
/*
* This looks up the name in dcache and possibly revalidates the found dentry.
* NULL is returned if the dentry does not exist in the cache.
@@ -1785,6 +1689,102 @@ static const char *step_into(struct nameidata *nd, int flags,
return pick_link(nd, &path, inode, seq, flags);
}
+static int follow_dotdot_rcu(struct nameidata *nd)
+{
+ struct dentry *parent = NULL;
+ struct inode *inode = nd->inode;
+ unsigned seq;
+
+ while (1) {
+ if (path_equal(&nd->path, &nd->root))
+ break;
+ if (nd->path.dentry != nd->path.mnt->mnt_root) {
+ struct dentry *old = nd->path.dentry;
+
+ parent = old->d_parent;
+ inode = parent->d_inode;
+ seq = read_seqcount_begin(&parent->d_seq);
+ if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq)))
+ return -ECHILD;
+ if (unlikely(!path_connected(nd->path.mnt, parent)))
+ return -ECHILD;
+ break;
+ } else {
+ struct mount *mnt = real_mount(nd->path.mnt);
+ struct mount *mparent = mnt->mnt_parent;
+ struct dentry *mountpoint = mnt->mnt_mountpoint;
+ struct inode *inode2 = mountpoint->d_inode;
+ unsigned seq = read_seqcount_begin(&mountpoint->d_seq);
+ if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
+ return -ECHILD;
+ if (&mparent->mnt == nd->path.mnt)
+ break;
+ if (unlikely(nd->flags & LOOKUP_NO_XDEV))
+ return -ECHILD;
+ /* we know that mountpoint was pinned */
+ nd->path.dentry = mountpoint;
+ nd->path.mnt = &mparent->mnt;
+ inode = inode2;
+ nd->seq = seq;
+ }
+ }
+ if (unlikely(!parent)) {
+ if (unlikely(nd->flags & LOOKUP_BENEATH))
+ return -ECHILD;
+ } else {
+ nd->path.dentry = parent;
+ nd->seq = seq;
+ }
+ while (unlikely(d_mountpoint(nd->path.dentry))) {
+ struct mount *mounted;
+ mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
+ if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
+ return -ECHILD;
+ if (!mounted)
+ break;
+ if (unlikely(nd->flags & LOOKUP_NO_XDEV))
+ return -ECHILD;
+ nd->path.mnt = &mounted->mnt;
+ nd->path.dentry = mounted->mnt.mnt_root;
+ inode = nd->path.dentry->d_inode;
+ nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
+ }
+ nd->inode = inode;
+ return 0;
+}
+
+static int follow_dotdot(struct nameidata *nd)
+{
+ struct dentry *parent = NULL;
+ while (1) {
+ if (path_equal(&nd->path, &nd->root))
+ break;
+ if (nd->path.dentry != nd->path.mnt->mnt_root) {
+ /* rare case of legitimate dget_parent()... */
+ parent = dget_parent(nd->path.dentry);
+ if (unlikely(!path_connected(nd->path.mnt, parent))) {
+ dput(parent);
+ return -ENOENT;
+ }
+ break;
+ }
+ if (!follow_up(&nd->path))
+ break;
+ if (unlikely(nd->flags & LOOKUP_NO_XDEV))
+ return -EXDEV;
+ }
+ if (unlikely(!parent)) {
+ if (unlikely(nd->flags & LOOKUP_BENEATH))
+ return -EXDEV;
+ } else {
+ dput(nd->path.dentry);
+ nd->path.dentry = parent;
+ }
+ follow_mount(&nd->path);
+ nd->inode = nd->path.dentry->d_inode;
+ return 0;
+}
+
static const char *handle_dots(struct nameidata *nd, int type, int flags)
{
if (type == LAST_DOTDOT) {
--
2.11.0
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