#include <linux/capability.h>
#include <linux/file.h>
#include <linux/fcntl.h>
-#include <linux/namei.h>
#include <asm/namei.h>
#include <asm/uaccess.h>
* any extra contention...
*/
+static int fastcall link_path_walk(const char *name, struct nameidata *nd);
+
/* In order to reduce some races, while at the same time doing additional
* checking and hopefully speeding things up, we copy filenames to the
* kernel data space before using them..
int permission(struct inode *inode, int mask, struct nameidata *nd)
{
- umode_t mode = inode->i_mode;
int retval, submask;
+ struct vfsmount *mnt = NULL;
+
+ if (nd)
+ mnt = nd->mnt;
if (mask & MAY_WRITE) {
+ umode_t mode = inode->i_mode;
/*
* Nobody gets write access to a read-only fs.
return -EACCES;
}
-
- /*
- * MAY_EXEC on regular files requires special handling: We override
- * filesystem execute permissions if the mode bits aren't set or
- * the fs is mounted with the "noexec" flag.
- */
- if ((mask & MAY_EXEC) && S_ISREG(mode) && (!(mode & S_IXUGO) ||
- (nd && nd->mnt && (nd->mnt->mnt_flags & MNT_NOEXEC))))
- return -EACCES;
+ if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
+ /*
+ * MAY_EXEC on regular files is denied if the fs is mounted
+ * with the "noexec" flag.
+ */
+ if (mnt && (mnt->mnt_flags & MNT_NOEXEC))
+ return -EACCES;
+ }
/* Ordinary permission routines do not understand MAY_APPEND. */
submask = mask & ~MAY_APPEND;
- if (inode->i_op && inode->i_op->permission)
+ if (inode->i_op && inode->i_op->permission) {
retval = inode->i_op->permission(inode, submask, nd);
- else
+ if (!retval) {
+ /*
+ * Exec permission on a regular file is denied if none
+ * of the execute bits are set.
+ *
+ * This check should be done by the ->permission()
+ * method.
+ */
+ if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode) &&
+ !(inode->i_mode & S_IXUGO))
+ return -EACCES;
+ }
+ } else {
retval = generic_permission(inode, submask, NULL);
+ }
if (retval)
return retval;
* Retry the whole path once, forcing real lookup requests
* instead of relying on the dcache.
*/
-int fastcall link_path_walk(const char *name, struct nameidata *nd)
+static int fastcall link_path_walk(const char *name, struct nameidata *nd)
{
struct nameidata save = *nd;
int result;
return result;
}
-int fastcall path_walk(const char * name, struct nameidata *nd)
+static int fastcall path_walk(const char * name, struct nameidata *nd)
{
current->total_link_count = 0;
return link_path_walk(name, nd);
return do_path_lookup(AT_FDCWD, name, flags, nd);
}
+/**
+ * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
+ * @dentry: pointer to dentry of the base directory
+ * @mnt: pointer to vfs mount of the base directory
+ * @name: pointer to file name
+ * @flags: lookup flags
+ * @nd: pointer to nameidata
+ */
+int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
+ const char *name, unsigned int flags,
+ struct nameidata *nd)
+{
+ int retval;
+
+ /* same as do_path_lookup */
+ nd->last_type = LAST_ROOT;
+ nd->flags = flags;
+ nd->depth = 0;
+
+ nd->mnt = mntget(mnt);
+ nd->dentry = dget(dentry);
+
+ retval = path_walk(name, nd);
+ if (unlikely(!retval && !audit_dummy_context() && nd->dentry &&
+ nd->dentry->d_inode))
+ audit_inode(name, nd->dentry->d_inode);
+
+ return retval;
+
+}
+
static int __path_lookup_intent_open(int dfd, const char *name,
unsigned int lookup_flags, struct nameidata *nd,
int open_flags, int create_mode)
return err;
}
-static inline struct dentry *__lookup_hash_kern(struct qstr *name, struct dentry *base, struct nameidata *nd)
+static struct dentry *__lookup_hash(struct qstr *name,
+ struct dentry *base, struct nameidata *nd)
{
struct dentry *dentry;
struct inode *inode;
* needs parent already locked. Doesn't follow mounts.
* SMP-safe.
*/
-static inline struct dentry * __lookup_hash(struct qstr *name, struct dentry *base, struct nameidata *nd)
+static struct dentry *lookup_hash(struct nameidata *nd)
{
- struct dentry *dentry;
- struct inode *inode;
int err;
- inode = base->d_inode;
-
- err = permission(inode, MAY_EXEC, nd);
- dentry = ERR_PTR(err);
+ err = permission(nd->dentry->d_inode, MAY_EXEC, nd);
if (err)
- goto out;
-
- dentry = __lookup_hash_kern(name, base, nd);
-out:
- return dentry;
-}
-
-static struct dentry *lookup_hash(struct nameidata *nd)
-{
+ return ERR_PTR(err);
return __lookup_hash(&nd->last, nd->dentry, nd);
}
-/* SMP-safe */
-static inline int __lookup_one_len(const char *name, struct qstr *this, struct dentry *base, int len)
+static int __lookup_one_len(const char *name, struct qstr *this,
+ struct dentry *base, int len)
{
unsigned long hash;
unsigned int c;
return 0;
}
+/**
+ * lookup_one_len: filesystem helper to lookup single pathname component
+ * @name: pathname component to lookup
+ * @base: base directory to lookup from
+ * @len: maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem useage and should
+ * not be called by generic code. Also note that by using this function to
+ * nameidata argument is passed to the filesystem methods and a filesystem
+ * using this helper needs to be prepared for that.
+ */
struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
{
int err;
struct qstr this;
err = __lookup_one_len(name, &this, base, len);
+ if (err)
+ return ERR_PTR(err);
+
+ err = permission(base->d_inode, MAY_EXEC, NULL);
if (err)
return ERR_PTR(err);
return __lookup_hash(&this, base, NULL);
}
-struct dentry *lookup_one_len_kern(const char *name, struct dentry *base, int len)
+/**
+ * lookup_one_noperm - bad hack for sysfs
+ * @name: pathname component to lookup
+ * @base: base directory to lookup from
+ *
+ * This is a variant of lookup_one_len that doesn't perform any permission
+ * checks. It's a horrible hack to work around the braindead sysfs
+ * architecture and should not be used anywhere else.
+ *
+ * DON'T USE THIS FUNCTION EVER, thanks.
+ */
+struct dentry *lookup_one_noperm(const char *name, struct dentry *base)
{
int err;
struct qstr this;
- err = __lookup_one_len(name, &this, base, len);
+ err = __lookup_one_len(name, &this, base, strlen(name));
if (err)
return ERR_PTR(err);
- return __lookup_hash_kern(&this, base, NULL);
+ return __lookup_hash(&this, base, NULL);
}
int fastcall __user_walk_fd(int dfd, const char __user *name, unsigned flags,
if (S_ISDIR(inode->i_mode) && (flag & FMODE_WRITE))
return -EISDIR;
- error = vfs_permission(nd, acc_mode);
- if (error)
- return error;
-
/*
* FIFO's, sockets and device files are special: they don't
* actually live on the filesystem itself, and as such you
flag &= ~O_TRUNC;
} else if (IS_RDONLY(inode) && (flag & FMODE_WRITE))
return -EROFS;
+
+ error = vfs_permission(nd, acc_mode);
+ if (error)
+ return error;
/*
* An append-only file must be opened in append mode for writing.
*/
error = locks_verify_locked(inode);
if (!error) {
DQUOT_INIT(inode);
-
- error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL);
+
+ error = do_truncate(dentry, 0,
+ ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
+ NULL);
}
put_write_access(inode);
if (error)
{
struct address_space *mapping = inode->i_mapping;
struct page *page;
+ void *fsdata;
int err;
char *kaddr;
retry:
- err = -ENOMEM;
- page = find_or_create_page(mapping, 0, gfp_mask);
- if (!page)
- goto fail;
- err = mapping->a_ops->prepare_write(NULL, page, 0, len-1);
- if (err == AOP_TRUNCATED_PAGE) {
- page_cache_release(page);
- goto retry;
- }
+ err = pagecache_write_begin(NULL, mapping, 0, len-1,
+ AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
if (err)
- goto fail_map;
+ goto fail;
+
kaddr = kmap_atomic(page, KM_USER0);
memcpy(kaddr, symname, len-1);
kunmap_atomic(kaddr, KM_USER0);
- err = mapping->a_ops->commit_write(NULL, page, 0, len-1);
- if (err == AOP_TRUNCATED_PAGE) {
- page_cache_release(page);
- goto retry;
- }
- if (err)
- goto fail_map;
- /*
- * Notice that we are _not_ going to block here - end of page is
- * unmapped, so this will only try to map the rest of page, see
- * that it is unmapped (typically even will not look into inode -
- * ->i_size will be enough for everything) and zero it out.
- * OTOH it's obviously correct and should make the page up-to-date.
- */
- if (!PageUptodate(page)) {
- err = mapping->a_ops->readpage(NULL, page);
- if (err != AOP_TRUNCATED_PAGE)
- wait_on_page_locked(page);
- } else {
- unlock_page(page);
- }
- page_cache_release(page);
+
+ err = pagecache_write_end(NULL, mapping, 0, len-1, len-1,
+ page, fsdata);
if (err < 0)
goto fail;
+ if (err < len-1)
+ goto retry;
+
mark_inode_dirty(inode);
return 0;
-fail_map:
- unlock_page(page);
- page_cache_release(page);
fail:
return err;
}
EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(page_symlink_inode_operations);
EXPORT_SYMBOL(path_lookup);
+EXPORT_SYMBOL(vfs_path_lookup);
EXPORT_SYMBOL(path_release);
-EXPORT_SYMBOL(path_walk);
EXPORT_SYMBOL(permission);
EXPORT_SYMBOL(vfs_permission);
EXPORT_SYMBOL(file_permission);
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff