Merge git://www.linux-watchdog.org/linux-watchdog

[cascardo/linux.git] / fs / open.c

diff --git a/fs/open.c b/fs/open.c
index 182d866..9b33c0c 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -61,33 +61,22 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
        return ret;
 }
 
-static long do_sys_truncate(const char __user *pathname, loff_t length)
+long vfs_truncate(struct path *path, loff_t length)
 {
-       struct path path;
        struct inode *inode;
-       int error;
-
-       error = -EINVAL;
-       if (length < 0) /* sorry, but loff_t says... */
-               goto out;
+       long error;
 
-       error = user_path(pathname, &path);
-       if (error)
-               goto out;
-       inode = path.dentry->d_inode;
+       inode = path->dentry->d_inode;
 
        /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
-       error = -EISDIR;
        if (S_ISDIR(inode->i_mode))
-               goto dput_and_out;
-
-       error = -EINVAL;
+               return -EISDIR;
        if (!S_ISREG(inode->i_mode))
-               goto dput_and_out;
+               return -EINVAL;
 
-       error = mnt_want_write(path.mnt);
+       error = mnt_want_write(path->mnt);
        if (error)
-               goto dput_and_out;
+               goto out;
 
        error = inode_permission(inode, MAY_WRITE);
        if (error)
@@ -111,19 +100,40 @@ static long do_sys_truncate(const char __user *pathname, loff_t length)
 
        error = locks_verify_truncate(inode, NULL, length);
        if (!error)
-               error = security_path_truncate(&path);
+               error = security_path_truncate(path);
        if (!error)
-               error = do_truncate(path.dentry, length, 0, NULL);
+               error = do_truncate(path->dentry, length, 0, NULL);
 
 put_write_and_out:
        put_write_access(inode);
 mnt_drop_write_and_out:
-       mnt_drop_write(path.mnt);
-dput_and_out:
-       path_put(&path);
+       mnt_drop_write(path->mnt);
 out:
        return error;
 }
+EXPORT_SYMBOL_GPL(vfs_truncate);
+
+static long do_sys_truncate(const char __user *pathname, loff_t length)
+{
+       unsigned int lookup_flags = LOOKUP_FOLLOW;
+       struct path path;
+       int error;
+
+       if (length < 0) /* sorry, but loff_t says... */
+               return -EINVAL;
+
+retry:
+       error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
+       if (!error) {
+               error = vfs_truncate(&path, length);
+               path_put(&path);
+       }
+       if (retry_estale(error, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
+       return error;
+}
 
 SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
 {
@@ -306,6 +316,7 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
        struct path path;
        struct inode *inode;
        int res;
+       unsigned int lookup_flags = LOOKUP_FOLLOW;
 
        if (mode & ~S_IRWXO)    /* where's F_OK, X_OK, W_OK, R_OK? */
                return -EINVAL;
@@ -328,8 +339,8 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
        }
 
        old_cred = override_creds(override_cred);
-
-       res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
+retry:
+       res = user_path_at(dfd, filename, lookup_flags, &path);
        if (res)
                goto out;
 
@@ -364,6 +375,10 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
 
 out_path_release:
        path_put(&path);
+       if (retry_estale(res, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
 out:
        revert_creds(old_cred);
        put_cred(override_cred);
@@ -379,8 +394,9 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
 {
        struct path path;
        int error;
-
-       error = user_path_dir(filename, &path);
+       unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+retry:
+       error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
        if (error)
                goto out;
 
@@ -392,6 +408,10 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
 
 dput_and_out:
        path_put(&path);
+       if (retry_estale(error, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
 out:
        return error;
 }
@@ -425,8 +445,9 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
 {
        struct path path;
        int error;
-
-       error = user_path_dir(filename, &path);
+       unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+retry:
+       error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
        if (error)
                goto out;
 
@@ -445,6 +466,10 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
        error = 0;
 dput_and_out:
        path_put(&path);
+       if (retry_estale(error, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
 out:
        return error;
 }
@@ -489,11 +514,16 @@ SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode
 {
        struct path path;
        int error;
-
-       error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
+       unsigned int lookup_flags = LOOKUP_FOLLOW;
+retry:
+       error = user_path_at(dfd, filename, lookup_flags, &path);
        if (!error) {
                error = chmod_common(&path, mode);
                path_put(&path);
+               if (retry_estale(error, lookup_flags)) {
+                       lookup_flags |= LOOKUP_REVAL;
+                       goto retry;
+               }
        }
        return error;
 }
@@ -552,6 +582,7 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
        lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
        if (flag & AT_EMPTY_PATH)
                lookup_flags |= LOOKUP_EMPTY;
+retry:
        error = user_path_at(dfd, filename, lookup_flags, &path);
        if (error)
                goto out;
@@ -562,6 +593,10 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
        mnt_drop_write(path.mnt);
 out_release:
        path_put(&path);
+       if (retry_estale(error, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
 out:
        return error;
 }