btrfs: fix uncheck memory allocation in btrfs_submit_compressed_read

btrfs_submit_compressed_read() is lack of memory allocation checks and corresponding error route. After this fix, if it comes to "no memory" case, errno will be returned to userland step by step, and tell users this operation cannot go on. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>

btrfs: fix uncheck memory allocation in btrfs_submit_compressed_read
btrfs_submit_compressed_read() is lack of memory allocation checks and corresponding error route. After this fix, if it comes to "no memory" case, errno will be returned to userland step by step, and tell users this operation cannot go on. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
liubo · Chris Mason
1 parent eab49bec41
Showing 2 changed files with 25 additions and 4 deletions Side-by-side Diff
fs/btrfs/compression.c
fs/btrfs/extent_io.c
@@ -562,7 +562,7 @@
 	u64 em_len;
 	u64 em_start;
 	struct extent_map *em;
-	int ret;
+	int ret = -ENOMEM;
 	u32 *sums;
  
 	tree = &BTRFS_I(inode)->io_tree;
@@ -577,6 +577,9 @@
  
 	compressed_len = em->block_len;
 	cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);
+	if (!cb)
+		goto out;
+
 	atomic_set(&cb->pending_bios, 0);
 	cb->errors = 0;
 	cb->inode = inode;
  
  
@@ -597,13 +600,18 @@
  
 	nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /
 				 PAGE_CACHE_SIZE;
-	cb->compressed_pages = kmalloc(sizeof(struct page *) * nr_pages,
+	cb->compressed_pages = kzalloc(sizeof(struct page *) * nr_pages,
 				       GFP_NOFS);
+	if (!cb->compressed_pages)
+		goto fail1;
+
 	bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
  
 	for (page_index = 0; page_index < nr_pages; page_index++) {
 		cb->compressed_pages[page_index] = alloc_page(GFP_NOFS |
 							      __GFP_HIGHMEM);
+		if (!cb->compressed_pages[page_index])
+			goto fail2;
 	}
 	cb->nr_pages = nr_pages;
  
@@ -614,6 +622,8 @@
 	cb->len = uncompressed_len;
  
 	comp_bio = compressed_bio_alloc(bdev, cur_disk_byte, GFP_NOFS);
+	if (!comp_bio)
+		goto fail2;
 	comp_bio->bi_private = cb;
 	comp_bio->bi_end_io = end_compressed_bio_read;
 	atomic_inc(&cb->pending_bios);
@@ -681,6 +691,17 @@
  
 	bio_put(comp_bio);
 	return 0;
+
+fail2:
+	for (page_index = 0; page_index < nr_pages; page_index++)
+		free_page((unsigned long)cb->compressed_pages[page_index]);
+
+	kfree(cb->compressed_pages);
+fail1:
+	kfree(cb);
+out:
+	free_extent_map(em);
+	return ret;
 }
  
 static struct list_head comp_idle_workspace[BTRFS_COMPRESS_TYPES];
@@ -1865,7 +1865,7 @@
 	bio_get(bio);
  
 	if (tree->ops && tree->ops->submit_bio_hook)
-		tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
+		ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
 					   mirror_num, bio_flags, start);
 	else
 		submit_bio(rw, bio);
@@ -2126,7 +2126,7 @@
 	ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
 				      &bio_flags);
 	if (bio)
-		submit_one_bio(READ, bio, 0, bio_flags);
+		ret = submit_one_bio(READ, bio, 0, bio_flags);
 	return ret;
 }
...	...	@@ -562,7 +562,7 @@
562	562	u64 em_len;
563	563	u64 em_start;
564	564	struct extent_map *em;
565		- int ret;
	565	+ int ret = -ENOMEM;
566	566	u32 *sums;
567	567
568	568	tree = &BTRFS_I(inode)->io_tree;
...	...	@@ -577,6 +577,9 @@
577	577
578	578	compressed_len = em->block_len;
579	579	cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);
	580	+ if (!cb)
	581	+ goto out;
	582	+
580	583	atomic_set(&cb->pending_bios, 0);
581	584	cb->errors = 0;
582	585	cb->inode = inode;
583	586
584	587
...	...	@@ -597,13 +600,18 @@
597	600
598	601	nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /
599	602	PAGE_CACHE_SIZE;
600		- cb->compressed_pages = kmalloc(sizeof(struct page ) nr_pages,
	603	+ cb->compressed_pages = kzalloc(sizeof(struct page ) nr_pages,
601	604	GFP_NOFS);
	605	+ if (!cb->compressed_pages)
	606	+ goto fail1;
	607	+
602	608	bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
603	609
604	610	for (page_index = 0; page_index < nr_pages; page_index++) {
605	611	cb->compressed_pages[page_index] = alloc_page(GFP_NOFS \|
606	612	__GFP_HIGHMEM);
	613	+ if (!cb->compressed_pages[page_index])
	614	+ goto fail2;
607	615	}
608	616	cb->nr_pages = nr_pages;
609	617
...	...	@@ -614,6 +622,8 @@
614	622	cb->len = uncompressed_len;
615	623
616	624	comp_bio = compressed_bio_alloc(bdev, cur_disk_byte, GFP_NOFS);
	625	+ if (!comp_bio)
	626	+ goto fail2;
617	627	comp_bio->bi_private = cb;
618	628	comp_bio->bi_end_io = end_compressed_bio_read;
619	629	atomic_inc(&cb->pending_bios);
...	...	@@ -681,6 +691,17 @@
681	691
682	692	bio_put(comp_bio);
683	693	return 0;
	694	+
	695	+fail2:
	696	+ for (page_index = 0; page_index < nr_pages; page_index++)
	697	+ free_page((unsigned long)cb->compressed_pages[page_index]);
	698	+
	699	+ kfree(cb->compressed_pages);
	700	+fail1:
	701	+ kfree(cb);
	702	+out:
	703	+ free_extent_map(em);
	704	+ return ret;
684	705	}
685	706
686	707	static struct list_head comp_idle_workspace[BTRFS_COMPRESS_TYPES];
...	...	@@ -1865,7 +1865,7 @@
1865	1865	bio_get(bio);
1866	1866
1867	1867	if (tree->ops && tree->ops->submit_bio_hook)
1868		- tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
	1868	+ ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
1869	1869	mirror_num, bio_flags, start);
1870	1870	else
1871	1871	submit_bio(rw, bio);
...	...	@@ -2126,7 +2126,7 @@
2126	2126	ret = __extent_read_full_page(tree, page, get_extent, &bio, 0,
2127	2127	&bio_flags);
2128	2128	if (bio)
2129		- submit_one_bio(READ, bio, 0, bio_flags);
	2129	+ ret = submit_one_bio(READ, bio, 0, bio_flags);
2130	2130	return ret;
2131	2131	}
2132	2132