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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-15 09:58:14 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-15 09:58:14 -0800
commit84bf39461e61f69ebfbfecf39cfda71bf78a7fc1 (patch)
tree54c5be5e59aa58acf45491d63583904ba86a0c64 /fs
parent95e20af9fb9ce572129b930967dcb762a318c588 (diff)
parent508c8772760d4ef9c1a044519b564710c3684fc5 (diff)
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro: "Fixes for mountpoint_last() bugs (by converting to use of lookup_last()) and an autofs regression fix from this cycle (caused by follow_managed() breakage introduced in barrier fixes series)" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix autofs regression caused by follow_managed() changes reimplement path_mountpoint() with less magic
Diffstat (limited to 'fs')
-rw-r--r--fs/namei.c90
-rw-r--r--fs/nfs/nfstrace.h2
2 files changed, 13 insertions, 79 deletions
diff --git a/fs/namei.c b/fs/namei.c
index d6c91d1e88cb..d2720dc71d0e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1232,6 +1232,7 @@ static int follow_managed(struct path *path, struct nameidata *nd)
BUG_ON(!path->dentry->d_op);
BUG_ON(!path->dentry->d_op->d_manage);
ret = path->dentry->d_op->d_manage(path, false);
+ flags = smp_load_acquire(&path->dentry->d_flags);
if (ret < 0)
break;
}
@@ -1649,17 +1650,15 @@ again:
if (IS_ERR(dentry))
return dentry;
if (unlikely(!d_in_lookup(dentry))) {
- if (!(flags & LOOKUP_NO_REVAL)) {
- int error = d_revalidate(dentry, flags);
- if (unlikely(error <= 0)) {
- if (!error) {
- d_invalidate(dentry);
- dput(dentry);
- goto again;
- }
+ int error = d_revalidate(dentry, flags);
+ if (unlikely(error <= 0)) {
+ if (!error) {
+ d_invalidate(dentry);
dput(dentry);
- dentry = ERR_PTR(error);
+ goto again;
}
+ dput(dentry);
+ dentry = ERR_PTR(error);
}
} else {
old = inode->i_op->lookup(inode, dentry, flags);
@@ -2618,72 +2617,6 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
EXPORT_SYMBOL(user_path_at_empty);
/**
- * mountpoint_last - look up last component for umount
- * @nd: pathwalk nameidata - currently pointing at parent directory of "last"
- *
- * This is a special lookup_last function just for umount. In this case, we
- * need to resolve the path without doing any revalidation.
- *
- * The nameidata should be the result of doing a LOOKUP_PARENT pathwalk. Since
- * mountpoints are always pinned in the dcache, their ancestors are too. Thus,
- * in almost all cases, this lookup will be served out of the dcache. The only
- * cases where it won't are if nd->last refers to a symlink or the path is
- * bogus and it doesn't exist.
- *
- * Returns:
- * -error: if there was an error during lookup. This includes -ENOENT if the
- * lookup found a negative dentry.
- *
- * 0: if we successfully resolved nd->last and found it to not to be a
- * symlink that needs to be followed.
- *
- * 1: if we successfully resolved nd->last and found it to be a symlink
- * that needs to be followed.
- */
-static int
-mountpoint_last(struct nameidata *nd)
-{
- int error = 0;
- struct dentry *dir = nd->path.dentry;
- struct path path;
-
- /* If we're in rcuwalk, drop out of it to handle last component */
- if (nd->flags & LOOKUP_RCU) {
- if (unlazy_walk(nd))
- return -ECHILD;
- }
-
- nd->flags &= ~LOOKUP_PARENT;
-
- if (unlikely(nd->last_type != LAST_NORM)) {
- error = handle_dots(nd, nd->last_type);
- if (error)
- return error;
- path.dentry = dget(nd->path.dentry);
- } else {
- path.dentry = d_lookup(dir, &nd->last);
- if (!path.dentry) {
- /*
- * No cached dentry. Mounted dentries are pinned in the
- * cache, so that means that this dentry is probably
- * a symlink or the path doesn't actually point
- * to a mounted dentry.
- */
- path.dentry = lookup_slow(&nd->last, dir,
- nd->flags | LOOKUP_NO_REVAL);
- if (IS_ERR(path.dentry))
- return PTR_ERR(path.dentry);
- }
- }
- if (d_flags_negative(smp_load_acquire(&path.dentry->d_flags))) {
- dput(path.dentry);
- return -ENOENT;
- }
- path.mnt = nd->path.mnt;
- return step_into(nd, &path, 0, d_backing_inode(path.dentry), 0);
-}
-
-/**
* path_mountpoint - look up a path to be umounted
* @nd: lookup context
* @flags: lookup flags
@@ -2699,14 +2632,17 @@ path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
int err;
while (!(err = link_path_walk(s, nd)) &&
- (err = mountpoint_last(nd)) > 0) {
+ (err = lookup_last(nd)) > 0) {
s = trailing_symlink(nd);
}
+ if (!err && (nd->flags & LOOKUP_RCU))
+ err = unlazy_walk(nd);
+ if (!err)
+ err = handle_lookup_down(nd);
if (!err) {
*path = nd->path;
nd->path.mnt = NULL;
nd->path.dentry = NULL;
- follow_mount(path);
}
terminate_walk(nd);
return err;
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index f64a33d2a1d1..2a82dcce5fc1 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -206,7 +206,6 @@ TRACE_DEFINE_ENUM(LOOKUP_AUTOMOUNT);
TRACE_DEFINE_ENUM(LOOKUP_PARENT);
TRACE_DEFINE_ENUM(LOOKUP_REVAL);
TRACE_DEFINE_ENUM(LOOKUP_RCU);
-TRACE_DEFINE_ENUM(LOOKUP_NO_REVAL);
TRACE_DEFINE_ENUM(LOOKUP_OPEN);
TRACE_DEFINE_ENUM(LOOKUP_CREATE);
TRACE_DEFINE_ENUM(LOOKUP_EXCL);
@@ -224,7 +223,6 @@ TRACE_DEFINE_ENUM(LOOKUP_DOWN);
{ LOOKUP_PARENT, "PARENT" }, \
{ LOOKUP_REVAL, "REVAL" }, \
{ LOOKUP_RCU, "RCU" }, \
- { LOOKUP_NO_REVAL, "NO_REVAL" }, \
{ LOOKUP_OPEN, "OPEN" }, \
{ LOOKUP_CREATE, "CREATE" }, \
{ LOOKUP_EXCL, "EXCL" }, \

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