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 <[email protected]> --- 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 2011-01-03 21:16:12.000000000 +0800 +++ linux/fs/btrfs/disk-io.c 2011-01-03 21:16:19.000000000 +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 2010-12-31 08:52:00.000000000 +0800 +++ linux/fs/btrfs/disk-io.h 2011-01-03 21:16:19.000000000 +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 2010-12-31 08:52:00.000000000 +0800 +++ linux/fs/btrfs/extent_io.c 2011-01-03 21:16:19.000000000 +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 2010-12-31 08:52:00.000000000 +0800 +++ linux/fs/btrfs/extent_io.h 2011-01-03 21:16:19.000000000 +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 2010-12-31 08:52:00.000000000 +0800 +++ linux/fs/btrfs/extent-tree.c 2011-01-03 21:16:19.000000000 +0800 @@ -5606,6 +5606,7 @@ 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) { -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
