btrfs: Don't BUG_ON errors from btrfs_create_subvol_root()

[cascardo/linux.git] / fs / btrfs / ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 03bb62a..de25e42 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -430,6 +430,11 @@ static noinline int create_subvol(struct btrfs_root *root,
        btrfs_record_root_in_trans(trans, new_root);
 
        ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
+       if (ret) {
+               /* We potentially lose an unused inode item here */
+               goto fail;
+       }
+
        /*
         * insert the directory item
         */
@@ -797,9 +802,9 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 
        if (!em) {
                /* get the big lock and read metadata off disk */
-               lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
+               lock_extent(io_tree, start, start + len - 1);
                em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
-               unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
+               unlock_extent(io_tree, start, start + len - 1);
 
                if (IS_ERR(em))
                        return 0;
@@ -861,6 +866,7 @@ static int cluster_pages_for_defrag(struct inode *inode,
        int i_done;
        struct btrfs_ordered_extent *ordered;
        struct extent_state *cached_state = NULL;
+       struct extent_io_tree *tree;
        gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 
        if (isize == 0)
@@ -871,18 +877,34 @@ static int cluster_pages_for_defrag(struct inode *inode,
                                           num_pages << PAGE_CACHE_SHIFT);
        if (ret)
                return ret;
-again:
-       ret = 0;
        i_done = 0;
+       tree = &BTRFS_I(inode)->io_tree;
 
        /* step one, lock all the pages */
        for (i = 0; i < num_pages; i++) {
                struct page *page;
+again:
                page = find_or_create_page(inode->i_mapping,
-                                           start_index + i, mask);
+                                          start_index + i, mask);
                if (!page)
                        break;
 
+               page_start = page_offset(page);
+               page_end = page_start + PAGE_CACHE_SIZE - 1;
+               while (1) {
+                       lock_extent(tree, page_start, page_end);
+                       ordered = btrfs_lookup_ordered_extent(inode,
+                                                             page_start);
+                       unlock_extent(tree, page_start, page_end);
+                       if (!ordered)
+                               break;
+
+                       unlock_page(page);
+                       btrfs_start_ordered_extent(inode, ordered, 1);
+                       btrfs_put_ordered_extent(ordered);
+                       lock_page(page);
+               }
+
                if (!PageUptodate(page)) {
                        btrfs_readpage(NULL, page);
                        lock_page(page);
@@ -893,15 +915,22 @@ again:
                                break;
                        }
                }
+
                isize = i_size_read(inode);
                file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
-               if (!isize || page->index > file_end ||
-                   page->mapping != inode->i_mapping) {
+               if (!isize || page->index > file_end) {
                        /* whoops, we blew past eof, skip this page */
                        unlock_page(page);
                        page_cache_release(page);
                        break;
                }
+
+               if (page->mapping != inode->i_mapping) {
+                       unlock_page(page);
+                       page_cache_release(page);
+                       goto again;
+               }
+
                pages[i] = page;
                i_done++;
        }
@@ -922,27 +951,7 @@ again:
        page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
 
        lock_extent_bits(&BTRFS_I(inode)->io_tree,
-                        page_start, page_end - 1, 0, &cached_state,
-                        GFP_NOFS);
-       ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1);
-       if (ordered &&
-           ordered->file_offset + ordered->len > page_start &&
-           ordered->file_offset < page_end) {
-               btrfs_put_ordered_extent(ordered);
-               unlock_extent_cached(&BTRFS_I(inode)->io_tree,
-                                    page_start, page_end - 1,
-                                    &cached_state, GFP_NOFS);
-               for (i = 0; i < i_done; i++) {
-                       unlock_page(pages[i]);
-                       page_cache_release(pages[i]);
-               }
-               btrfs_wait_ordered_range(inode, page_start,
-                                        page_end - page_start);
-               goto again;
-       }
-       if (ordered)
-               btrfs_put_ordered_extent(ordered);
-
+                        page_start, page_end - 1, 0, &cached_state);
        clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
                          page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
                          EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
@@ -1327,6 +1336,12 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
                goto out;
        }
 
+       if (name[0] == '.' &&
+          (namelen == 1 || (name[1] == '.' && namelen == 2))) {
+               ret = -EEXIST;
+               goto out;
+       }
+
        if (subvol) {
                ret = btrfs_mksubvol(&file->f_path, name, namelen,
                                     NULL, transid, readonly);
@@ -2315,13 +2330,13 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
           another, and lock file content */
        while (1) {
                struct btrfs_ordered_extent *ordered;
-               lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
+               lock_extent(&BTRFS_I(src)->io_tree, off, off+len);
                ordered = btrfs_lookup_first_ordered_extent(src, off+len);
                if (!ordered &&
                    !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
                                   EXTENT_DELALLOC, 0, NULL))
                        break;
-               unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
+               unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
                if (ordered)
                        btrfs_put_ordered_extent(ordered);
                btrfs_wait_ordered_range(src, off, len);
@@ -2540,7 +2555,7 @@ next:
        ret = 0;
 out:
        btrfs_release_path(path);
-       unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
+       unlock_extent(&BTRFS_I(src)->io_tree, off, off+len);
 out_unlock:
        mutex_unlock(&src->i_mutex);
        mutex_unlock(&inode->i_mutex);