forked from Minki/linux
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
This commit is contained in:
Linus Torvalds
commit
84bf39461e
90
fs/namei.c
90
fs/namei.c
@ -1232,6 +1232,7 @@ static int follow_managed(struct path *path, struct nameidata *nd)
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BUG_ON(!path->dentry->d_op);
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BUG_ON(!path->dentry->d_op->d_manage);
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ret = path->dentry->d_op->d_manage(path, false);
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flags = smp_load_acquire(&path->dentry->d_flags);
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if (ret < 0)
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break;
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}
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@ -1649,17 +1650,15 @@ again:
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if (IS_ERR(dentry))
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return dentry;
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if (unlikely(!d_in_lookup(dentry))) {
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if (!(flags & LOOKUP_NO_REVAL)) {
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int error = d_revalidate(dentry, flags);
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if (unlikely(error <= 0)) {
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if (!error) {
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d_invalidate(dentry);
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dput(dentry);
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goto again;
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}
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int error = d_revalidate(dentry, flags);
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if (unlikely(error <= 0)) {
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if (!error) {
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d_invalidate(dentry);
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dput(dentry);
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dentry = ERR_PTR(error);
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goto again;
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}
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dput(dentry);
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dentry = ERR_PTR(error);
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}
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} else {
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old = inode->i_op->lookup(inode, dentry, flags);
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@ -2617,72 +2616,6 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
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}
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EXPORT_SYMBOL(user_path_at_empty);
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/**
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* mountpoint_last - look up last component for umount
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* @nd: pathwalk nameidata - currently pointing at parent directory of "last"
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*
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* This is a special lookup_last function just for umount. In this case, we
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* need to resolve the path without doing any revalidation.
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*
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* The nameidata should be the result of doing a LOOKUP_PARENT pathwalk. Since
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* mountpoints are always pinned in the dcache, their ancestors are too. Thus,
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* in almost all cases, this lookup will be served out of the dcache. The only
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* cases where it won't are if nd->last refers to a symlink or the path is
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* bogus and it doesn't exist.
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*
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* Returns:
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* -error: if there was an error during lookup. This includes -ENOENT if the
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* lookup found a negative dentry.
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*
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* 0: if we successfully resolved nd->last and found it to not to be a
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* symlink that needs to be followed.
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*
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* 1: if we successfully resolved nd->last and found it to be a symlink
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* that needs to be followed.
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*/
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static int
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mountpoint_last(struct nameidata *nd)
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{
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int error = 0;
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struct dentry *dir = nd->path.dentry;
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struct path path;
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/* If we're in rcuwalk, drop out of it to handle last component */
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if (nd->flags & LOOKUP_RCU) {
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if (unlazy_walk(nd))
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return -ECHILD;
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}
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nd->flags &= ~LOOKUP_PARENT;
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if (unlikely(nd->last_type != LAST_NORM)) {
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error = handle_dots(nd, nd->last_type);
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if (error)
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return error;
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path.dentry = dget(nd->path.dentry);
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} else {
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path.dentry = d_lookup(dir, &nd->last);
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if (!path.dentry) {
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/*
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* No cached dentry. Mounted dentries are pinned in the
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* cache, so that means that this dentry is probably
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* a symlink or the path doesn't actually point
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* to a mounted dentry.
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*/
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path.dentry = lookup_slow(&nd->last, dir,
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nd->flags | LOOKUP_NO_REVAL);
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if (IS_ERR(path.dentry))
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return PTR_ERR(path.dentry);
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}
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}
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if (d_flags_negative(smp_load_acquire(&path.dentry->d_flags))) {
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dput(path.dentry);
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return -ENOENT;
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}
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path.mnt = nd->path.mnt;
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return step_into(nd, &path, 0, d_backing_inode(path.dentry), 0);
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}
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/**
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* path_mountpoint - look up a path to be umounted
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* @nd: lookup context
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@ -2699,14 +2632,17 @@ path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
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int err;
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while (!(err = link_path_walk(s, nd)) &&
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(err = mountpoint_last(nd)) > 0) {
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(err = lookup_last(nd)) > 0) {
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s = trailing_symlink(nd);
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}
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if (!err && (nd->flags & LOOKUP_RCU))
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err = unlazy_walk(nd);
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if (!err)
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err = handle_lookup_down(nd);
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if (!err) {
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*path = nd->path;
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nd->path.mnt = NULL;
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nd->path.dentry = NULL;
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follow_mount(path);
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}
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terminate_walk(nd);
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return err;
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@ -206,7 +206,6 @@ TRACE_DEFINE_ENUM(LOOKUP_AUTOMOUNT);
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TRACE_DEFINE_ENUM(LOOKUP_PARENT);
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TRACE_DEFINE_ENUM(LOOKUP_REVAL);
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TRACE_DEFINE_ENUM(LOOKUP_RCU);
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TRACE_DEFINE_ENUM(LOOKUP_NO_REVAL);
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TRACE_DEFINE_ENUM(LOOKUP_OPEN);
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TRACE_DEFINE_ENUM(LOOKUP_CREATE);
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TRACE_DEFINE_ENUM(LOOKUP_EXCL);
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@ -224,7 +223,6 @@ TRACE_DEFINE_ENUM(LOOKUP_DOWN);
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{ LOOKUP_PARENT, "PARENT" }, \
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{ LOOKUP_REVAL, "REVAL" }, \
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{ LOOKUP_RCU, "RCU" }, \
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{ LOOKUP_NO_REVAL, "NO_REVAL" }, \
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{ LOOKUP_OPEN, "OPEN" }, \
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{ LOOKUP_CREATE, "CREATE" }, \
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{ LOOKUP_EXCL, "EXCL" }, \
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@ -34,7 +34,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
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/* internal use only */
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#define LOOKUP_PARENT 0x0010
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#define LOOKUP_NO_REVAL 0x0080
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#define LOOKUP_JUMPED 0x1000
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#define LOOKUP_ROOT 0x2000
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#define LOOKUP_ROOT_GRABBED 0x0008
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