#include <linux/fcntl.h>
#include <linux/device_cgroup.h>
#include <linux/fs_struct.h>
+#include <linux/posix_acl.h>
#include <asm/uaccess.h>
#include "internal.h"
EXPORT_SYMBOL(putname);
#endif
+static int check_acl(struct inode *inode, int mask)
+{
+#ifdef CONFIG_FS_POSIX_ACL
+ struct posix_acl *acl;
+
+ if (mask & MAY_NOT_BLOCK) {
+ acl = get_cached_acl_rcu(inode, ACL_TYPE_ACCESS);
+ if (!acl)
+ return -EAGAIN;
+ /* no ->get_acl() calls in RCU mode... */
+ if (acl == ACL_NOT_CACHED)
+ return -ECHILD;
+ return posix_acl_permission(inode, acl, mask);
+ }
+
+ acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
+
+ /*
+ * A filesystem can force a ACL callback by just never filling the
+ * ACL cache. But normally you'd fill the cache either at inode
+ * instantiation time, or on the first ->get_acl call.
+ *
+ * If the filesystem doesn't have a get_acl() function at all, we'll
+ * just create the negative cache entry.
+ */
+ if (acl == ACL_NOT_CACHED) {
+ if (inode->i_op->get_acl) {
+ acl = inode->i_op->get_acl(inode, ACL_TYPE_ACCESS);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ } else {
+ set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
+ return -EAGAIN;
+ }
+ }
+
+ if (acl) {
+ int error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ return error;
+ }
+#endif
+
+ return -EAGAIN;
+}
+
/*
* This does basic POSIX ACL permission checking
*/
-static int acl_permission_check(struct inode *inode, int mask, unsigned int flags,
- int (*check_acl)(struct inode *inode, int mask, unsigned int flags))
+static int acl_permission_check(struct inode *inode, int mask)
{
unsigned int mode = inode->i_mode;
- mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
+ mask &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK;
if (current_user_ns() != inode_userns(inode))
goto other_perms;
- if (current_fsuid() == inode->i_uid)
+ if (likely(current_fsuid() == inode->i_uid))
mode >>= 6;
else {
- if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
- int error = check_acl(inode, mask, flags);
+ if (IS_POSIXACL(inode) && (mode & S_IRWXG)) {
+ int error = check_acl(inode, mask);
if (error != -EAGAIN)
return error;
}
/*
* If the DACs are ok we don't need any capability check.
*/
- if ((mask & ~mode) == 0)
+ if ((mask & ~mode & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
return 0;
return -EACCES;
}
* generic_permission - check for access rights on a Posix-like filesystem
* @inode: inode to check access rights for
* @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
- * @check_acl: optional callback to check for Posix ACLs
- * @flags: IPERM_FLAG_ flags.
*
* Used to check for read/write/execute permissions on a file.
* We use "fsuid" for this, letting us set arbitrary permissions
* request cannot be satisfied (eg. requires blocking or too much complexity).
* It would then be called again in ref-walk mode.
*/
-int generic_permission(struct inode *inode, int mask, unsigned int flags,
- int (*check_acl)(struct inode *inode, int mask, unsigned int flags))
+int generic_permission(struct inode *inode, int mask)
{
int ret;
/*
* Do the basic POSIX ACL permission checks.
*/
- ret = acl_permission_check(inode, mask, flags, check_acl);
+ ret = acl_permission_check(inode, mask);
if (ret != -EACCES)
return ret;
+ if (S_ISDIR(inode->i_mode)) {
+ /* DACs are overridable for directories */
+ if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE))
+ return 0;
+ if (!(mask & MAY_WRITE))
+ if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH))
+ return 0;
+ return -EACCES;
+ }
/*
* Read/write DACs are always overridable.
- * Executable DACs are overridable if at least one exec bit is set.
+ * Executable DACs are overridable when there is
+ * at least one exec bit set.
*/
- if (!(mask & MAY_EXEC) || execute_ok(inode))
+ if (!(mask & MAY_EXEC) || (inode->i_mode & S_IXUGO))
if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE))
return 0;
* Searching includes executable on directories, else just read.
*/
mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
- if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
+ if (mask == MAY_READ)
if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH))
return 0;
return -EACCES;
}
+/*
+ * We _really_ want to just do "generic_permission()" without
+ * even looking at the inode->i_op values. So we keep a cache
+ * flag in inode->i_opflags, that says "this has not special
+ * permission function, use the fast case".
+ */
+static inline int do_inode_permission(struct inode *inode, int mask)
+{
+ if (unlikely(!(inode->i_opflags & IOP_FASTPERM))) {
+ if (likely(inode->i_op->permission))
+ return inode->i_op->permission(inode, mask);
+
+ /* This gets set once for the inode lifetime */
+ spin_lock(&inode->i_lock);
+ inode->i_opflags |= IOP_FASTPERM;
+ spin_unlock(&inode->i_lock);
+ }
+ return generic_permission(inode, mask);
+}
+
/**
* inode_permission - check for access rights to a given inode
* @inode: inode to check permission on
{
int retval;
- if (mask & MAY_WRITE) {
+ if (unlikely(mask & MAY_WRITE)) {
umode_t mode = inode->i_mode;
/*
return -EACCES;
}
- if (inode->i_op->permission)
- retval = inode->i_op->permission(inode, mask, 0);
- else
- retval = generic_permission(inode, mask, 0,
- inode->i_op->check_acl);
-
+ retval = do_inode_permission(inode, mask);
if (retval)
return retval;
return security_inode_permission(inode, mask);
}
-/**
- * file_permission - check for additional access rights to a given file
- * @file: file to check access rights for
- * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
- *
- * Used to check for read/write/execute permissions on an already opened
- * file.
- *
- * Note:
- * Do not use this function in new code. All access checks should
- * be done using inode_permission().
- */
-int file_permission(struct file *file, int mask)
-{
- return inode_permission(file->f_path.dentry->d_inode, mask);
-}
-
-/*
- * get_write_access() gets write permission for a file.
- * put_write_access() releases this write permission.
- * This is used for regular files.
- * We cannot support write (and maybe mmap read-write shared) accesses and
- * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
- * can have the following values:
- * 0: no writers, no VM_DENYWRITE mappings
- * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
- * > 0: (i_writecount) users are writing to the file.
- *
- * Normally we operate on that counter with atomic_{inc,dec} and it's safe
- * except for the cases where we don't hold i_writecount yet. Then we need to
- * use {get,deny}_write_access() - these functions check the sign and refuse
- * to do the change if sign is wrong. Exclusion between them is provided by
- * the inode->i_lock spinlock.
- */
-
-int get_write_access(struct inode * inode)
-{
- spin_lock(&inode->i_lock);
- if (atomic_read(&inode->i_writecount) < 0) {
- spin_unlock(&inode->i_lock);
- return -ETXTBSY;
- }
- atomic_inc(&inode->i_writecount);
- spin_unlock(&inode->i_lock);
-
- return 0;
-}
-
-int deny_write_access(struct file * file)
-{
- struct inode *inode = file->f_path.dentry->d_inode;
-
- spin_lock(&inode->i_lock);
- if (atomic_read(&inode->i_writecount) > 0) {
- spin_unlock(&inode->i_lock);
- return -ETXTBSY;
- }
- atomic_dec(&inode->i_writecount);
- spin_unlock(&inode->i_lock);
-
- return 0;
-}
-
/**
* path_get - get a reference to a path
* @path: path to get the reference to
goto err_parent;
BUG_ON(nd->inode != parent->d_inode);
} else {
+ if (dentry->d_parent != parent)
+ goto err_parent;
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
if (!__d_rcu_to_refcount(dentry, nd->seq))
goto err_child;
return dentry->d_op->d_revalidate(dentry, nd);
}
-static struct dentry *
-do_revalidate(struct dentry *dentry, struct nameidata *nd)
-{
- int status = d_revalidate(dentry, nd);
- if (unlikely(status <= 0)) {
- /*
- * The dentry failed validation.
- * If d_revalidate returned 0 attempt to invalidate
- * the dentry otherwise d_revalidate is asking us
- * to return a fail status.
- */
- if (status < 0) {
- dput(dentry);
- dentry = ERR_PTR(status);
- } else if (!d_invalidate(dentry)) {
- dput(dentry);
- dentry = NULL;
- }
- }
- return dentry;
-}
-
/**
* complete_walk - successful completion of path walk
* @nd: pointer nameidata
return status;
}
-/*
- * Short-cut version of permission(), for calling on directories
- * during pathname resolution. Combines parts of permission()
- * and generic_permission(), and tests ONLY for MAY_EXEC permission.
- *
- * If appropriate, check DAC only. If not appropriate, or
- * short-cut DAC fails, then call ->permission() to do more
- * complete permission check.
- */
-static inline int exec_permission(struct inode *inode, unsigned int flags)
-{
- int ret;
- struct user_namespace *ns = inode_userns(inode);
-
- if (inode->i_op->permission) {
- ret = inode->i_op->permission(inode, MAY_EXEC, flags);
- } else {
- ret = acl_permission_check(inode, MAY_EXEC, flags,
- inode->i_op->check_acl);
- }
- if (likely(!ret))
- goto ok;
- if (ret == -ECHILD)
- return ret;
-
- if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
- ns_capable(ns, CAP_DAC_READ_SEARCH))
- goto ok;
-
- return ret;
-ok:
- return security_inode_exec_permission(inode, flags);
-}
-
static __always_inline void set_root(struct nameidata *nd)
{
if (!nd->root.mnt)
/* We don't want to mount if someone supplied AT_NO_AUTOMOUNT
* and this is the terminal part of the path.
*/
- if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_CONTINUE))
+ if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_PARENT))
return -EISDIR; /* we actually want to stop here */
- /* We want to mount if someone is trying to open/create a file of any
- * type under the mountpoint, wants to traverse through the mountpoint
- * or wants to open the mounted directory.
- *
+ /*
* We don't want to mount if someone's just doing a stat and they've
* set AT_SYMLINK_NOFOLLOW - unless they're stat'ing a directory and
* appended a '/' to the name.
*/
- if (!(flags & LOOKUP_FOLLOW) &&
- !(flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY |
- LOOKUP_OPEN | LOOKUP_CREATE)))
- return -EISDIR;
-
+ if (!(flags & LOOKUP_FOLLOW)) {
+ /* We do, however, want to mount if someone wants to open or
+ * create a file of any type under the mountpoint, wants to
+ * traverse through the mountpoint or wants to open the mounted
+ * directory.
+ * Also, autofs may mark negative dentries as being automount
+ * points. These will need the attentions of the daemon to
+ * instantiate them before they can be used.
+ */
+ if (!(flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
+ LOOKUP_OPEN | LOOKUP_CREATE)) &&
+ path->dentry->d_inode)
+ return -EISDIR;
+ }
current->total_link_count++;
if (current->total_link_count >= 40)
return -ELOOP;
* the path being looked up; if it wasn't then the remainder of
* the path is inaccessible and we should say so.
*/
- if (PTR_ERR(mnt) == -EISDIR && (flags & LOOKUP_CONTINUE))
+ if (PTR_ERR(mnt) == -EISDIR && (flags & LOOKUP_PARENT))
return -EREMOTE;
return PTR_ERR(mnt);
}
if (!mnt) /* mount collision */
return 0;
+ if (!*need_mntput) {
+ /* lock_mount() may release path->mnt on error */
+ mntget(path->mnt);
+ *need_mntput = true;
+ }
err = finish_automount(mnt, path);
switch (err) {
/* Someone else made a mount here whilst we were busy */
return 0;
case 0:
- dput(path->dentry);
- if (*need_mntput)
- mntput(path->mnt);
+ path_put(path);
path->mnt = mnt;
path->dentry = dget(mnt->mnt_root);
- *need_mntput = true;
return 0;
default:
return err;
*/
static int follow_managed(struct path *path, unsigned flags)
{
+ struct vfsmount *mnt = path->mnt; /* held by caller, must be left alone */
unsigned managed;
bool need_mntput = false;
- int ret;
+ int ret = 0;
/* Given that we're not holding a lock here, we retain the value in a
* local variable for each dentry as we look at it so that we don't see
BUG_ON(!path->dentry->d_op->d_manage);
ret = path->dentry->d_op->d_manage(path->dentry, false);
if (ret < 0)
- return ret == -EISDIR ? 0 : ret;
+ break;
}
/* Transit to a mounted filesystem. */
if (managed & DCACHE_NEED_AUTOMOUNT) {
ret = follow_automount(path, flags, &need_mntput);
if (ret < 0)
- return ret == -EISDIR ? 0 : ret;
+ break;
continue;
}
/* We didn't change the current path point */
break;
}
- return 0;
+
+ if (need_mntput && path->mnt == mnt)
+ mntput(path->mnt);
+ if (ret == -EISDIR)
+ ret = 0;
+ return ret;
}
int follow_down_one(struct path *path)
* Don't forget we might have a non-mountpoint managed dentry
* that wants to block transit.
*/
- *inode = path->dentry->d_inode;
if (unlikely(managed_dentry_might_block(path->dentry)))
return false;
path->mnt = mounted;
path->dentry = mounted->mnt_root;
nd->seq = read_seqcount_begin(&path->dentry->d_seq);
+ /*
+ * Update the inode too. We don't need to re-check the
+ * dentry sequence number here after this d_inode read,
+ * because a mount-point is always pinned.
+ */
+ *inode = path->dentry->d_inode;
}
return true;
}
* Follow down to the covering mount currently visible to userspace. At each
* point, the filesystem owning that dentry may be queried as to whether the
* caller is permitted to proceed or not.
- *
- * Care must be taken as namespace_sem may be held (indicated by mounting_here
- * being true).
*/
int follow_down(struct path *path)
{
return dentry;
}
+/*
+ * We already have a dentry, but require a lookup to be performed on the parent
+ * directory to fill in d_inode. Returns the new dentry, or ERR_PTR on error.
+ * parent->d_inode->i_mutex must be held. d_lookup must have verified that no
+ * child exists while under i_mutex.
+ */
+static struct dentry *d_inode_lookup(struct dentry *parent, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct inode *inode = parent->d_inode;
+ struct dentry *old;
+
+ /* Don't create child dentry for a dead directory. */
+ if (unlikely(IS_DEADDIR(inode)))
+ return ERR_PTR(-ENOENT);
+
+ old = inode->i_op->lookup(inode, dentry, nd);
+ if (unlikely(old)) {
+ dput(dentry);
+ dentry = old;
+ }
+ return dentry;
+}
+
/*
* It's more convoluted than I'd like it to be, but... it's still fairly
* small and for now I'd prefer to have fast path as straight as possible.
goto unlazy;
}
}
+ if (unlikely(d_need_lookup(dentry)))
+ goto unlazy;
path->mnt = mnt;
path->dentry = dentry;
if (unlikely(!__follow_mount_rcu(nd, path, inode)))
dentry = __d_lookup(parent, name);
}
+ if (dentry && unlikely(d_need_lookup(dentry))) {
+ dput(dentry);
+ dentry = NULL;
+ }
retry:
if (unlikely(!dentry)) {
struct inode *dir = parent->d_inode;
/* known good */
need_reval = 0;
status = 1;
+ } else if (unlikely(d_need_lookup(dentry))) {
+ dentry = d_inode_lookup(parent, dentry, nd);
+ if (IS_ERR(dentry)) {
+ mutex_unlock(&dir->i_mutex);
+ return PTR_ERR(dentry);
+ }
+ /* known good */
+ need_reval = 0;
+ status = 1;
}
mutex_unlock(&dir->i_mutex);
}
static inline int may_lookup(struct nameidata *nd)
{
if (nd->flags & LOOKUP_RCU) {
- int err = exec_permission(nd->inode, IPERM_FLAG_RCU);
+ int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
if (err != -ECHILD)
return err;
if (unlazy_walk(nd, NULL))
return -ECHILD;
}
- return exec_permission(nd->inode, 0);
+ return inode_permission(nd->inode, MAY_EXEC);
}
static inline int handle_dots(struct nameidata *nd, int type)
}
}
+/*
+ * Do we need to follow links? We _really_ want to be able
+ * to do this check without having to look at inode->i_op,
+ * so we keep a cache of "no, this doesn't need follow_link"
+ * for the common case.
+ */
+static inline int do_follow_link(struct inode *inode, int follow)
+{
+ if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) {
+ if (likely(inode->i_op->follow_link))
+ return follow;
+
+ /* This gets set once for the inode lifetime */
+ spin_lock(&inode->i_lock);
+ inode->i_opflags |= IOP_NOFOLLOW;
+ spin_unlock(&inode->i_lock);
+ }
+ return 0;
+}
+
static inline int walk_component(struct nameidata *nd, struct path *path,
struct qstr *name, int type, int follow)
{
terminate_walk(nd);
return -ENOENT;
}
- if (unlikely(inode->i_op->follow_link) && follow) {
+ if (do_follow_link(inode, follow)) {
if (nd->flags & LOOKUP_RCU) {
if (unlikely(unlazy_walk(nd, path->dentry))) {
terminate_walk(nd);
return res;
}
+/*
+ * We really don't want to look at inode->i_op->lookup
+ * when we don't have to. So we keep a cache bit in
+ * the inode ->i_opflags field that says "yes, we can
+ * do lookup on this inode".
+ */
+static inline int can_lookup(struct inode *inode)
+{
+ if (likely(inode->i_opflags & IOP_LOOKUP))
+ return 1;
+ if (likely(!inode->i_op->lookup))
+ return 0;
+
+ /* We do this once for the lifetime of the inode */
+ spin_lock(&inode->i_lock);
+ inode->i_opflags |= IOP_LOOKUP;
+ spin_unlock(&inode->i_lock);
+ return 1;
+}
+
/*
* Name resolution.
* This is the basic name resolution function, turning a pathname into
{
struct path next;
int err;
- unsigned int lookup_flags = nd->flags;
while (*name=='/')
name++;
unsigned int c;
int type;
- nd->flags |= LOOKUP_CONTINUE;
-
err = may_lookup(nd);
if (err)
break;
if (err)
return err;
}
+ if (can_lookup(nd->inode))
+ continue;
err = -ENOTDIR;
- if (!nd->inode->i_op->lookup)
- break;
- continue;
+ break;
/* here ends the main loop */
last_component:
- /* Clear LOOKUP_CONTINUE iff it was previously unset */
- nd->flags &= lookup_flags | ~LOOKUP_CONTINUE;
nd->last = this;
nd->last_type = type;
return 0;
if (!S_ISDIR(dentry->d_inode->i_mode))
goto fput_fail;
- retval = file_permission(file, MAY_EXEC);
+ retval = inode_permission(dentry->d_inode, MAY_EXEC);
if (retval)
goto fput_fail;
}
* @mnt: pointer to vfs mount of the base directory
* @name: pointer to file name
* @flags: lookup flags
- * @nd: pointer to nameidata
+ * @path: pointer to struct path to fill
*/
int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
const char *name, unsigned int flags,
- struct nameidata *nd)
+ struct path *path)
{
- nd->root.dentry = dentry;
- nd->root.mnt = mnt;
+ struct nameidata nd;
+ int err;
+ nd.root.dentry = dentry;
+ nd.root.mnt = mnt;
+ BUG_ON(flags & LOOKUP_PARENT);
/* the first argument of do_path_lookup() is ignored with LOOKUP_ROOT */
- return do_path_lookup(AT_FDCWD, name, flags | LOOKUP_ROOT, nd);
+ err = do_path_lookup(AT_FDCWD, name, flags | LOOKUP_ROOT, &nd);
+ if (!err)
+ *path = nd.path;
+ return err;
}
static struct dentry *__lookup_hash(struct qstr *name,
struct dentry *dentry;
int err;
- err = exec_permission(inode, 0);
+ err = inode_permission(inode, MAY_EXEC);
if (err)
return ERR_PTR(err);
*/
dentry = d_lookup(base, name);
- if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE))
- dentry = do_revalidate(dentry, nd);
+ if (dentry && d_need_lookup(dentry)) {
+ /*
+ * __lookup_hash is called with the parent dir's i_mutex already
+ * held, so we are good to go here.
+ */
+ dentry = d_inode_lookup(base, dentry, nd);
+ if (IS_ERR(dentry))
+ return dentry;
+ }
+
+ if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE)) {
+ int status = d_revalidate(dentry, nd);
+ if (unlikely(status <= 0)) {
+ /*
+ * The dentry failed validation.
+ * If d_revalidate returned 0 attempt to invalidate
+ * the dentry otherwise d_revalidate is asking us
+ * to return a fail status.
+ */
+ if (status < 0) {
+ dput(dentry);
+ return ERR_PTR(status);
+ } else if (!d_invalidate(dentry)) {
+ dput(dentry);
+ dentry = NULL;
+ }
+ }
+ }
if (!dentry)
dentry = d_alloc_and_lookup(base, name, nd);
return error;
}
-/*
- * Note that while the flag value (low two bits) for sys_open means:
- * 00 - read-only
- * 01 - write-only
- * 10 - read-write
- * 11 - special
- * it is changed into
- * 00 - no permissions needed
- * 01 - read-permission
- * 10 - write-permission
- * 11 - read-write
- * for the internal routines (ie open_namei()/follow_link() etc)
- * This is more logical, and also allows the 00 "no perm needed"
- * to be used for symlinks (where the permissions are checked
- * later).
- *
-*/
static inline int open_to_namei_flags(int flag)
{
- if ((flag+1) & O_ACCMODE)
- flag++;
+ if ((flag & O_ACCMODE) == 3)
+ flag--;
return flag;
}
return file;
}
-/**
- * lookup_create - lookup a dentry, creating it if it doesn't exist
- * @nd: nameidata info
- * @is_dir: directory flag
- *
- * Simple function to lookup and return a dentry and create it
- * if it doesn't exist. Is SMP-safe.
- *
- * Returns with nd->path.dentry->d_inode->i_mutex locked.
- */
-struct dentry *lookup_create(struct nameidata *nd, int is_dir)
+struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir)
{
struct dentry *dentry = ERR_PTR(-EEXIST);
+ struct nameidata nd;
+ int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);
+ if (error)
+ return ERR_PTR(error);
- mutex_lock_nested(&nd->path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
/*
* Yucky last component or no last component at all?
* (foo/., foo/.., /////)
*/
- if (nd->last_type != LAST_NORM)
- goto fail;
- nd->flags &= ~LOOKUP_PARENT;
- nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL;
- nd->intent.open.flags = O_EXCL;
+ if (nd.last_type != LAST_NORM)
+ goto out;
+ nd.flags &= ~LOOKUP_PARENT;
+ nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL;
+ nd.intent.open.flags = O_EXCL;
/*
* Do the final lookup.
*/
- dentry = lookup_hash(nd);
+ mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+ dentry = lookup_hash(&nd);
if (IS_ERR(dentry))
goto fail;
* all is fine. Let's be bastards - you had / on the end, you've
* been asking for (non-existent) directory. -ENOENT for you.
*/
- if (unlikely(!is_dir && nd->last.name[nd->last.len])) {
+ if (unlikely(!is_dir && nd.last.name[nd.last.len])) {
dput(dentry);
dentry = ERR_PTR(-ENOENT);
+ goto fail;
}
+ *path = nd.path;
return dentry;
eexist:
dput(dentry);
dentry = ERR_PTR(-EEXIST);
fail:
+ mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+out:
+ path_put(&nd.path);
return dentry;
}
-EXPORT_SYMBOL_GPL(lookup_create);
+EXPORT_SYMBOL(kern_path_create);
+
+struct dentry *user_path_create(int dfd, const char __user *pathname, struct path *path, int is_dir)
+{
+ char *tmp = getname(pathname);
+ struct dentry *res;
+ if (IS_ERR(tmp))
+ return ERR_CAST(tmp);
+ res = kern_path_create(dfd, tmp, path, is_dir);
+ putname(tmp);
+ return res;
+}
+EXPORT_SYMBOL(user_path_create);
int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode,
unsigned, dev)
{
- int error;
- char *tmp;
struct dentry *dentry;
- struct nameidata nd;
+ struct path path;
+ int error;
if (S_ISDIR(mode))
return -EPERM;
- error = user_path_parent(dfd, filename, &nd, &tmp);
- if (error)
- return error;
+ dentry = user_path_create(dfd, filename, &path, 0);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
- dentry = lookup_create(&nd, 0);
- if (IS_ERR(dentry)) {
- error = PTR_ERR(dentry);
- goto out_unlock;
- }
- if (!IS_POSIXACL(nd.path.dentry->d_inode))
+ if (!IS_POSIXACL(path.dentry->d_inode))
mode &= ~current_umask();
error = may_mknod(mode);
if (error)
goto out_dput;
- error = mnt_want_write(nd.path.mnt);
+ error = mnt_want_write(path.mnt);
if (error)
goto out_dput;
- error = security_path_mknod(&nd.path, dentry, mode, dev);
+ error = security_path_mknod(&path, dentry, mode, dev);
if (error)
goto out_drop_write;
switch (mode & S_IFMT) {
case 0: case S_IFREG:
- error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd);
+ error = vfs_create(path.dentry->d_inode,dentry,mode,NULL);
break;
case S_IFCHR: case S_IFBLK:
- error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,
+ error = vfs_mknod(path.dentry->d_inode,dentry,mode,
new_decode_dev(dev));
break;
case S_IFIFO: case S_IFSOCK:
- error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0);
+ error = vfs_mknod(path.dentry->d_inode,dentry,mode,0);
break;
}
out_drop_write:
- mnt_drop_write(nd.path.mnt);
+ mnt_drop_write(path.mnt);
out_dput:
dput(dentry);
-out_unlock:
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
- putname(tmp);
+ mutex_unlock(&path.dentry->d_inode->i_mutex);
+ path_put(&path);
return error;
}
SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode)
{
- int error = 0;
- char * tmp;
struct dentry *dentry;
- struct nameidata nd;
-
- error = user_path_parent(dfd, pathname, &nd, &tmp);
- if (error)
- goto out_err;
+ struct path path;
+ int error;
- dentry = lookup_create(&nd, 1);
- error = PTR_ERR(dentry);
+ dentry = user_path_create(dfd, pathname, &path, 1);
if (IS_ERR(dentry))
- goto out_unlock;
+ return PTR_ERR(dentry);
- if (!IS_POSIXACL(nd.path.dentry->d_inode))
+ if (!IS_POSIXACL(path.dentry->d_inode))
mode &= ~current_umask();
- error = mnt_want_write(nd.path.mnt);
+ error = mnt_want_write(path.mnt);
if (error)
goto out_dput;
- error = security_path_mkdir(&nd.path, dentry, mode);
+ error = security_path_mkdir(&path, dentry, mode);
if (error)
goto out_drop_write;
- error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
+ error = vfs_mkdir(path.dentry->d_inode, dentry, mode);
out_drop_write:
- mnt_drop_write(nd.path.mnt);
+ mnt_drop_write(path.mnt);
out_dput:
dput(dentry);
-out_unlock:
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
- putname(tmp);
-out_err:
+ mutex_unlock(&path.dentry->d_inode->i_mutex);
+ path_put(&path);
return error;
}
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto exit2;
+ if (!dentry->d_inode) {
+ error = -ENOENT;
+ goto exit3;
+ }
error = mnt_want_write(nd.path.mnt);
if (error)
goto exit3;
if (nd.last.name[nd.last.len])
goto slashes;
inode = dentry->d_inode;
- if (inode)
- ihold(inode);
+ if (!inode)
+ goto slashes;
+ ihold(inode);
error = mnt_want_write(nd.path.mnt);
if (error)
goto exit2;
{
int error;
char *from;
- char *to;
struct dentry *dentry;
- struct nameidata nd;
+ struct path path;
from = getname(oldname);
if (IS_ERR(from))
return PTR_ERR(from);
- error = user_path_parent(newdfd, newname, &nd, &to);
- if (error)
- goto out_putname;
-
- dentry = lookup_create(&nd, 0);
+ dentry = user_path_create(newdfd, newname, &path, 0);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
- goto out_unlock;
+ goto out_putname;
- error = mnt_want_write(nd.path.mnt);
+ error = mnt_want_write(path.mnt);
if (error)
goto out_dput;
- error = security_path_symlink(&nd.path, dentry, from);
+ error = security_path_symlink(&path, dentry, from);
if (error)
goto out_drop_write;
- error = vfs_symlink(nd.path.dentry->d_inode, dentry, from);
+ error = vfs_symlink(path.dentry->d_inode, dentry, from);
out_drop_write:
- mnt_drop_write(nd.path.mnt);
+ mnt_drop_write(path.mnt);
out_dput:
dput(dentry);
-out_unlock:
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
- putname(to);
+ mutex_unlock(&path.dentry->d_inode->i_mutex);
+ path_put(&path);
out_putname:
putname(from);
return error;
int, newdfd, const char __user *, newname, int, flags)
{
struct dentry *new_dentry;
- struct nameidata nd;
- struct path old_path;
+ struct path old_path, new_path;
int how = 0;
int error;
- char *to;
if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)
return -EINVAL;
if (error)
return error;
- error = user_path_parent(newdfd, newname, &nd, &to);
- if (error)
- goto out;
- error = -EXDEV;
- if (old_path.mnt != nd.path.mnt)
- goto out_release;
- new_dentry = lookup_create(&nd, 0);
+ new_dentry = user_path_create(newdfd, newname, &new_path, 0);
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
- goto out_unlock;
- error = mnt_want_write(nd.path.mnt);
+ goto out;
+
+ error = -EXDEV;
+ if (old_path.mnt != new_path.mnt)
+ goto out_dput;
+ error = mnt_want_write(new_path.mnt);
if (error)
goto out_dput;
- error = security_path_link(old_path.dentry, &nd.path, new_dentry);
+ error = security_path_link(old_path.dentry, &new_path, new_dentry);
if (error)
goto out_drop_write;
- error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry);
+ error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry);
out_drop_write:
- mnt_drop_write(nd.path.mnt);
+ mnt_drop_write(new_path.mnt);
out_dput:
dput(new_dentry);
-out_unlock:
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-out_release:
- path_put(&nd.path);
- putname(to);
+ mutex_unlock(&new_path.dentry->d_inode->i_mutex);
+ path_put(&new_path);
out:
path_put(&old_path);
EXPORT_SYMBOL(__page_symlink);
EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(page_symlink_inode_operations);
-EXPORT_SYMBOL(kern_path_parent);
EXPORT_SYMBOL(kern_path);
EXPORT_SYMBOL(vfs_path_lookup);
EXPORT_SYMBOL(inode_permission);
-EXPORT_SYMBOL(file_permission);
EXPORT_SYMBOL(unlock_rename);
EXPORT_SYMBOL(vfs_create);
EXPORT_SYMBOL(vfs_follow_link);
git.openpandora.org / pandora-kernel.git / blobdiff