do validation for extent_buffer if it's skipped before
With metadata readahead, we slightly change the behavior. Before it, we allocate
an extent_buffer (so set page->private), do metadata read and
btree_readpage_end_io_hook() will do validation. After it, we directly do
metadata readahead, and since in this case page hasn't ->private,
btree_readpage_end_io_hook() will not do validation. This patch fixes this.
It addes a new flag to indicate if a buffer is validated. If not and even
the buffer is uptodated, we will do a validation.
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
---
fs/btrfs/disk-io.c | 67 ++++++++++++++++++++++++++++++-------------------
fs/btrfs/disk-io.h | 2 +
fs/btrfs/extent-tree.c | 1
fs/btrfs/extent_io.c | 14 ++++++++--
fs/btrfs/extent_io.h | 1
5 files changed, 58 insertions(+), 27 deletions(-)
Index: linux/fs/btrfs/disk-io.c
===================================================================
--- linux.orig/fs/btrfs/disk-io.c 2010-12-07 14:53:54.000000000 +0800
+++ linux/fs/btrfs/disk-io.c 2010-12-07 14:53:59.000000000 +0800
@@ -406,30 +406,18 @@ void btrfs_set_buffer_lockdep_class(stru
}
#endif
-static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
- struct extent_state *state)
+int btree_validate_extent_buffer(struct btrfs_root *root,
+ struct extent_buffer *eb)
{
- struct extent_io_tree *tree;
+ int ret = 0;
u64 found_start;
int found_level;
- unsigned long len;
- struct extent_buffer *eb;
- struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
- int ret = 0;
-
- tree = &BTRFS_I(page->mapping->host)->io_tree;
- if (page->private == EXTENT_PAGE_PRIVATE)
- goto out;
- if (!page->private)
- goto out;
- len = page->private >> 2;
- WARN_ON(len == 0);
-
- eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
+ if (!test_bit(EXTENT_BUFFER_UNCHECKED, &eb->bflags))
+ return 0;
found_start = btrfs_header_bytenr(eb);
- if (found_start != start) {
+ if (found_start != eb->start) {
if (printk_ratelimit()) {
printk(KERN_INFO "btrfs bad tree block start "
"%llu %llu\n",
@@ -439,13 +427,7 @@ static int btree_readpage_end_io_hook(st
ret = -EIO;
goto err;
}
- if (eb->first_page != page) {
- printk(KERN_INFO "btrfs bad first page %lu %lu\n",
- eb->first_page->index, page->index);
- WARN_ON(1);
- ret = -EIO;
- goto err;
- }
+
if (check_tree_block_fsid(root, eb)) {
if (printk_ratelimit()) {
printk(KERN_INFO "btrfs bad fsid on block %llu\n",
@@ -461,6 +443,41 @@ static int btree_readpage_end_io_hook(st
ret = csum_tree_block(root, eb, 1);
if (ret)
ret = -EIO;
+err:
+ if (ret == 0)
+ clear_bit(EXTENT_BUFFER_UNCHECKED, &eb->bflags);
+ return ret;
+}
+
+static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
+ struct extent_state *state)
+{
+ struct extent_io_tree *tree;
+ unsigned long len;
+ struct extent_buffer *eb;
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+ int ret = 0;
+
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ if (page->private == EXTENT_PAGE_PRIVATE)
+ goto out;
+ if (!page->private)
+ goto out;
+
+ len = page->private >> 2;
+ WARN_ON(len == 0);
+
+ eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
+
+ if (eb->first_page != page) {
+ printk(KERN_INFO "btrfs bad first page %lu %lu\n",
+ eb->first_page->index, page->index);
+ WARN_ON(1);
+ ret = -EIO;
+ goto err;
+ }
+
+ ret = btree_validate_extent_buffer(root, eb);
end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
end = eb->start + end - 1;
Index: linux/fs/btrfs/disk-io.h
===================================================================
--- linux.orig/fs/btrfs/disk-io.h 2010-12-07 13:45:05.000000000 +0800
+++ linux/fs/btrfs/disk-io.h 2010-12-07 14:53:59.000000000 +0800
@@ -36,6 +36,8 @@ static inline u64 btrfs_sb_offset(int mi
struct btrfs_device;
struct btrfs_fs_devices;
+int btree_validate_extent_buffer(struct btrfs_root *root,
+ struct extent_buffer *eb);
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, u64 parent_transid);
int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
Index: linux/fs/btrfs/extent_io.c
===================================================================
--- linux.orig/fs/btrfs/extent_io.c 2010-12-07 13:45:05.000000000 +0800
+++ linux/fs/btrfs/extent_io.c 2010-12-07 14:53:59.000000000 +0800
@@ -14,6 +14,7 @@
#include "extent_map.h"
#include "compat.h"
#include "ctree.h"
+#include "disk-io.h"
#include "btrfs_inode.h"
static struct kmem_cache *extent_state_cache;
@@ -3189,6 +3190,7 @@ struct extent_buffer *alloc_extent_buffe
uptodate = 0;
unlock_page(p);
}
+ set_bit(EXTENT_BUFFER_UNCHECKED, &eb->bflags);
if (uptodate)
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
@@ -3419,9 +3421,10 @@ int read_extent_buffer_pages(struct exte
unsigned long num_pages;
struct bio *bio = NULL;
unsigned long bio_flags = 0;
+ struct btrfs_root *root = BTRFS_I(tree->mapping->host)->root;
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
- return 0;
+ goto out;
if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
EXTENT_UPTODATE, 1, NULL)) {
@@ -3486,8 +3489,10 @@ int read_extent_buffer_pages(struct exte
ret = -EIO;
}
- if (!ret)
+ if (!ret) {
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+ goto out;
+ }
return ret;
unlock_exit:
@@ -3498,6 +3503,11 @@ unlock_exit:
unlock_page(page);
locked_pages--;
}
+out:
+ if (!ret && test_bit(EXTENT_BUFFER_UNCHECKED, &eb->bflags) &&
+ test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
+ return btree_validate_extent_buffer(root, eb);
+
return ret;
}
Index: linux/fs/btrfs/extent_io.h
===================================================================
--- linux.orig/fs/btrfs/extent_io.h 2010-12-07 13:45:05.000000000 +0800
+++ linux/fs/btrfs/extent_io.h 2010-12-07 14:53:59.000000000 +0800
@@ -27,6 +27,7 @@
#define EXTENT_BUFFER_UPTODATE 0
#define EXTENT_BUFFER_BLOCKING 1
#define EXTENT_BUFFER_DIRTY 2
+#define EXTENT_BUFFER_UNCHECKED 3
/* these are flags for extent_clear_unlock_delalloc */
#define EXTENT_CLEAR_UNLOCK_PAGE 0x1
Index: linux/fs/btrfs/extent-tree.c
===================================================================
--- linux.orig/fs/btrfs/extent-tree.c 2010-12-07 13:45:05.000000000 +0800
+++ linux/fs/btrfs/extent-tree.c 2010-12-07 14:53:59.000000000 +0800
@@ -5573,6 +5573,7 @@ struct extent_buffer *btrfs_init_new_buf
clean_tree_block(trans, root, buf);
btrfs_set_lock_blocking(buf);
+ clear_bit(EXTENT_BUFFER_UNCHECKED, &buf->bflags);
btrfs_set_buffer_uptodate(buf);
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
--
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