[PATCH] autofs4: autofs4_follow_link false negative fix

[linux-2.6-omap-h63xx.git] / fs / autofs4 / root.c

diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 3f0048582248cad53bf930206e7bf6b0e888ed2d..0ec24835239f59a9b0b69e83f2abb48b4acd9b1e 100644 (file)
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -32,7 +32,7 @@ static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t fil
 static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
 static void *autofs4_follow_link(struct dentry *, struct nameidata *);
 
-struct file_operations autofs4_root_operations = {
+const struct file_operations autofs4_root_operations = {
        .open           = dcache_dir_open,
        .release        = dcache_dir_close,
        .read           = generic_read_dir,
@@ -40,7 +40,7 @@ struct file_operations autofs4_root_operations = {
        .ioctl          = autofs4_root_ioctl,
 };
 
-struct file_operations autofs4_dir_operations = {
+const struct file_operations autofs4_dir_operations = {
        .open           = autofs4_dir_open,
        .release        = autofs4_dir_close,
        .read           = generic_read_dir,
@@ -57,6 +57,9 @@ struct inode_operations autofs4_indirect_root_inode_operations = {
 
 struct inode_operations autofs4_direct_root_inode_operations = {
        .lookup         = autofs4_lookup,
+       .unlink         = autofs4_dir_unlink,
+       .mkdir          = autofs4_dir_mkdir,
+       .rmdir          = autofs4_dir_rmdir,
        .follow_link    = autofs4_follow_link,
 };
 
@@ -134,7 +137,9 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
                nd.flags = LOOKUP_DIRECTORY;
                ret = (dentry->d_op->d_revalidate)(dentry, &nd);
 
-               if (!ret) {
+               if (ret <= 0) {
+                       if (ret < 0)
+                               status = ret;
                        dcache_dir_close(inode, file);
                        goto out;
                }
@@ -324,6 +329,7 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
 static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
        struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+       struct autofs_info *ino = autofs4_dentry_ino(dentry);
        int oz_mode = autofs4_oz_mode(sbi);
        unsigned int lookup_type;
        int status;
@@ -337,15 +343,45 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
        if (oz_mode || !lookup_type)
                goto done;
 
-       status = try_to_fill_dentry(dentry, 0);
-       if (status)
-               goto out_error;
+       /* If an expire request is pending wait for it. */
+       if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
+               DPRINTK("waiting for active request %p name=%.*s",
+                       dentry, dentry->d_name.len, dentry->d_name.name);
+
+               status = autofs4_wait(sbi, dentry, NFY_NONE);
 
-       if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
-               status = -ENOENT;
-               goto out_error;
+               DPRINTK("request done status=%d", status);
        }
 
+       /*
+        * If the dentry contains directories then it is an
+        * autofs multi-mount with no root mount offset. So
+        * don't try to mount it again.
+        */
+       spin_lock(&dcache_lock);
+       if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
+               spin_unlock(&dcache_lock);
+
+               status = try_to_fill_dentry(dentry, 0);
+               if (status)
+                       goto out_error;
+
+               /*
+                * The mount succeeded but if there is no root mount
+                * it must be an autofs multi-mount with no root offset
+                * so we don't need to follow the mount.
+                */
+               if (d_mountpoint(dentry)) {
+                       if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
+                               status = -ENOENT;
+                               goto out_error;
+                       }
+               }
+
+               goto done;
+       }
+       spin_unlock(&dcache_lock);
+
 done:
        return NULL;
 
@@ -366,13 +402,23 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
        struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
        int oz_mode = autofs4_oz_mode(sbi);
        int flags = nd ? nd->flags : 0;
-       int status = 0;
+       int status = 1;
 
        /* Pending dentry */
        if (autofs4_ispending(dentry)) {
-               if (!oz_mode)
-                       status = try_to_fill_dentry(dentry, flags);
-               return !status;
+               /* The daemon never causes a mount to trigger */
+               if (oz_mode)
+                       return 1;
+
+               /*
+                * A zero status is success otherwise we have a
+                * negative error code.
+                */
+               status = try_to_fill_dentry(dentry, flags);
+               if (status == 0)
+                               return 1;
+
+               return status;
        }
 
        /* Negative dentry.. invalidate if "old" */
@@ -387,9 +433,19 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
                DPRINTK("dentry=%p %.*s, emptydir",
                         dentry, dentry->d_name.len, dentry->d_name.name);
                spin_unlock(&dcache_lock);
-               if (!oz_mode)
-                       status = try_to_fill_dentry(dentry, flags);
-               return !status;
+               /* The daemon never causes a mount to trigger */
+               if (oz_mode)
+                       return 1;
+
+               /*
+                * A zero status is success otherwise we have a
+                * negative error code.
+                */
+               status = try_to_fill_dentry(dentry, flags);
+               if (status == 0)
+                       return 1;
+
+               return status;
        }
        spin_unlock(&dcache_lock);