GFS2: Ensure uptodate inode size when using O_APPEND

[safe/jmp/linux-2.6] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index a765e7a..b55440b 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -37,8 +37,6 @@
 
 #include "internal.h"
 
-#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
-
 /* [Feb-1997 T. Schoebel-Theuer]
  * Fundamental changes in the pathname lookup mechanisms (namei)
  * were necessary because of omirr.  The reason is that omirr needs
@@ -234,6 +232,7 @@ int generic_permission(struct inode *inode, int mask,
        /*
         * 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 (capable(CAP_DAC_READ_SEARCH))
                        return 0;
@@ -414,6 +413,46 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
 }
 
 /*
+ * force_reval_path - force revalidation of a dentry
+ *
+ * In some situations the path walking code will trust dentries without
+ * revalidating them. This causes problems for filesystems that depend on
+ * d_revalidate to handle file opens (e.g. NFSv4). When FS_REVAL_DOT is set
+ * (which indicates that it's possible for the dentry to go stale), force
+ * a d_revalidate call before proceeding.
+ *
+ * Returns 0 if the revalidation was successful. If the revalidation fails,
+ * either return the error returned by d_revalidate or -ESTALE if the
+ * revalidation it just returned 0. If d_revalidate returns 0, we attempt to
+ * invalidate the dentry. It's up to the caller to handle putting references
+ * to the path if necessary.
+ */
+static int
+force_reval_path(struct path *path, struct nameidata *nd)
+{
+       int status;
+       struct dentry *dentry = path->dentry;
+
+       /*
+        * only check on filesystems where it's possible for the dentry to
+        * become stale. It's assumed that if this flag is set then the
+        * d_revalidate op will also be defined.
+        */
+       if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))
+               return 0;
+
+       status = dentry->d_op->d_revalidate(dentry, nd);
+       if (status > 0)
+               return 0;
+
+       if (!status) {
+               d_invalidate(dentry);
+               status = -ESTALE;
+       }
+       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.
@@ -529,6 +568,11 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata
                error = 0;
                if (s)
                        error = __vfs_follow_link(nd, s);
+               else if (nd->last_type == LAST_BIND) {
+                       error = force_reval_path(&nd->path, nd);
+                       if (error)
+                               path_put(&nd->path);
+               }
                if (dentry->d_inode->i_op->put_link)
                        dentry->d_inode->i_op->put_link(dentry, nd, cookie);
        }
@@ -1595,6 +1639,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
                if (filp == NULL)
                        return ERR_PTR(-ENFILE);
                nd.intent.open.file = filp;
+               filp->f_flags = open_flag;
                nd.intent.open.flags = flag;
                nd.intent.open.create_mode = 0;
                error = do_path_lookup(dfd, pathname,
@@ -1640,6 +1685,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
        if (filp == NULL)
                goto exit_parent;
        nd.intent.open.file = filp;
+       filp->f_flags = open_flag;
        nd.intent.open.flags = flag;
        nd.intent.open.create_mode = mode;
        dir = nd.path.dentry;
@@ -1680,7 +1726,7 @@ do_last:
                        mnt_drop_write(nd.path.mnt);
                        goto exit;
                }
-               filp = nameidata_to_filp(&nd, open_flag);
+               filp = nameidata_to_filp(&nd);
                mnt_drop_write(nd.path.mnt);
                if (nd.root.mnt)
                        path_put(&nd.root);
@@ -1719,7 +1765,7 @@ do_last:
 
        path_to_nameidata(&path, &nd);
        error = -EISDIR;
-       if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode))
+       if (S_ISDIR(path.dentry->d_inode->i_mode))
                goto exit;
 ok:
        /*
@@ -1744,7 +1790,7 @@ ok:
                        mnt_drop_write(nd.path.mnt);
                goto exit;
        }
-       filp = nameidata_to_filp(&nd, open_flag);
+       filp = nameidata_to_filp(&nd);
        if (!IS_ERR(filp)) {
                error = ima_path_check(&filp->f_path, filp->f_mode &
                               (MAY_READ | MAY_WRITE | MAY_EXEC));