From: Yan, Zheng Date: Thu, 12 Nov 2009 09:34:21 +0000 (+0000) Subject: Btrfs: Fix disk_i_size update corner case X-Git-Tag: v2.6.33-rc1~7^2~1^2~13 X-Git-Url: https://git.kernelconcepts.de/?a=commitdiff_plain;h=c216775458a2ee345d9412a2770c2916acfb5d30;p=karo-tx-linux.git Btrfs: Fix disk_i_size update corner case There are some cases file extents are inserted without involving ordered struct. In these cases, we update disk_i_size directly, without checking pending ordered extent and DELALLOC bit. This patch extends btrfs_ordered_update_i_size() to handle these cases. Signed-off-by: Yan Zheng Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index f6783a42f010..3f1f50d9d916 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -44,9 +44,6 @@ struct btrfs_inode { */ struct extent_io_tree io_failure_tree; - /* held while inesrting or deleting extents from files */ - struct mutex extent_mutex; - /* held while logging the inode in tree-log.c */ struct mutex log_mutex; @@ -166,7 +163,7 @@ static inline struct btrfs_inode *BTRFS_I(struct inode *inode) static inline void btrfs_i_size_write(struct inode *inode, u64 size) { - inode->i_size = size; + i_size_write(inode, size); BTRFS_I(inode)->disk_i_size = size; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index ef250be49cdb..fa57247887e3 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -188,8 +188,18 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); + /* + * we're an inline extent, so nobody can + * extend the file past i_size without locking + * a page we already have locked. + * + * We must do any isize and inode updates + * before we unlock the pages. Otherwise we + * could end up racing with unlink. + */ BTRFS_I(inode)->disk_i_size = inode->i_size; btrfs_update_inode(trans, root, inode); + return 0; fail: btrfs_free_path(path); @@ -415,7 +425,6 @@ again: start, end, total_compressed, pages); } - btrfs_end_transaction(trans, root); if (ret == 0) { /* * inline extent creation worked, we don't need @@ -429,9 +438,11 @@ again: EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_ACCOUNTING | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); - ret = 0; + + btrfs_end_transaction(trans, root); goto free_pages_out; } + btrfs_end_transaction(trans, root); } if (will_compress) { @@ -542,7 +553,6 @@ static noinline int submit_compressed_extents(struct inode *inode, if (list_empty(&async_cow->extents)) return 0; - trans = btrfs_join_transaction(root, 1); while (!list_empty(&async_cow->extents)) { async_extent = list_entry(async_cow->extents.next, @@ -589,19 +599,15 @@ retry: lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, GFP_NOFS); - /* - * here we're doing allocation and writeback of the - * compressed pages - */ - btrfs_drop_extent_cache(inode, async_extent->start, - async_extent->start + - async_extent->ram_size - 1, 0); + trans = btrfs_join_transaction(root, 1); ret = btrfs_reserve_extent(trans, root, async_extent->compressed_size, async_extent->compressed_size, 0, alloc_hint, (u64)-1, &ins, 1); + btrfs_end_transaction(trans, root); + if (ret) { int i; for (i = 0; i < async_extent->nr_pages; i++) { @@ -617,6 +623,14 @@ retry: goto retry; } + /* + * here we're doing allocation and writeback of the + * compressed pages + */ + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + em = alloc_extent_map(GFP_NOFS); em->start = async_extent->start; em->len = async_extent->ram_size; @@ -648,8 +662,6 @@ retry: BTRFS_ORDERED_COMPRESSED); BUG_ON(ret); - btrfs_end_transaction(trans, root); - /* * clear dirty, set writeback and unlock the pages. */ @@ -671,13 +683,11 @@ retry: async_extent->nr_pages); BUG_ON(ret); - trans = btrfs_join_transaction(root, 1); alloc_hint = ins.objectid + ins.offset; kfree(async_extent); cond_resched(); } - btrfs_end_transaction(trans, root); return 0; } @@ -741,6 +751,7 @@ static noinline int cow_file_range(struct inode *inode, EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); + *nr_written = *nr_written + (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; *page_started = 1; @@ -1727,18 +1738,27 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) } } - trans = btrfs_join_transaction(root, 1); - if (!ordered_extent) ordered_extent = btrfs_lookup_ordered_extent(inode, start); BUG_ON(!ordered_extent); - if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) - goto nocow; + if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { + BUG_ON(!list_empty(&ordered_extent->list)); + ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent); + if (!ret) { + trans = btrfs_join_transaction(root, 1); + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); + btrfs_end_transaction(trans, root); + } + goto out; + } lock_extent(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, GFP_NOFS); + trans = btrfs_join_transaction(root, 1); + if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) compressed = 1; if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { @@ -1765,22 +1785,20 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) unlock_extent(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, GFP_NOFS); -nocow: add_pending_csums(trans, inode, ordered_extent->file_offset, &ordered_extent->list); - mutex_lock(&BTRFS_I(inode)->extent_mutex); - btrfs_ordered_update_i_size(inode, ordered_extent); - btrfs_update_inode(trans, root, inode); - btrfs_remove_ordered_extent(inode, ordered_extent); - mutex_unlock(&BTRFS_I(inode)->extent_mutex); - + /* this also removes the ordered extent from the tree */ + btrfs_ordered_update_i_size(inode, 0, ordered_extent); + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); + btrfs_end_transaction(trans, root); +out: /* once for us */ btrfs_put_ordered_extent(ordered_extent); /* once for the tree */ btrfs_put_ordered_extent(ordered_extent); - btrfs_end_transaction(trans, root); return 0; } @@ -3562,7 +3580,6 @@ static noinline void init_btrfs_i(struct inode *inode) INIT_LIST_HEAD(&BTRFS_I(inode)->ordered_operations); RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree); - mutex_init(&BTRFS_I(inode)->extent_mutex); mutex_init(&BTRFS_I(inode)->log_mutex); } diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index 5799bc46a309..9b16073bb875 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -291,16 +291,16 @@ int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) /* * remove an ordered extent from the tree. No references are dropped - * but, anyone waiting on this extent is woken up. + * and you must wake_up entry->wait. You must hold the tree mutex + * while you call this function. */ -int btrfs_remove_ordered_extent(struct inode *inode, +static int __btrfs_remove_ordered_extent(struct inode *inode, struct btrfs_ordered_extent *entry) { struct btrfs_ordered_inode_tree *tree; struct rb_node *node; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); node = &entry->rb_node; rb_erase(node, &tree->tree); tree->last = NULL; @@ -326,9 +326,26 @@ int btrfs_remove_ordered_extent(struct inode *inode, } spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); + return 0; +} + +/* + * remove an ordered extent from the tree. No references are dropped + * but any waiters are woken. + */ +int btrfs_remove_ordered_extent(struct inode *inode, + struct btrfs_ordered_extent *entry) +{ + struct btrfs_ordered_inode_tree *tree; + int ret; + + tree = &BTRFS_I(inode)->ordered_tree; + mutex_lock(&tree->mutex); + ret = __btrfs_remove_ordered_extent(inode, entry); mutex_unlock(&tree->mutex); wake_up(&entry->wait); - return 0; + + return ret; } /* @@ -589,7 +606,7 @@ out: * After an extent is done, call this to conditionally update the on disk * i_size. i_size is updated to cover any fully written part of the file. */ -int btrfs_ordered_update_i_size(struct inode *inode, +int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, struct btrfs_ordered_extent *ordered) { struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; @@ -597,18 +614,30 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 disk_i_size; u64 new_i_size; u64 i_size_test; + u64 i_size = i_size_read(inode); struct rb_node *node; + struct rb_node *prev = NULL; struct btrfs_ordered_extent *test; + int ret = 1; + + if (ordered) + offset = entry_end(ordered); mutex_lock(&tree->mutex); disk_i_size = BTRFS_I(inode)->disk_i_size; + /* truncate file */ + if (disk_i_size > i_size) { + BTRFS_I(inode)->disk_i_size = i_size; + ret = 0; + goto out; + } + /* * if the disk i_size is already at the inode->i_size, or * this ordered extent is inside the disk i_size, we're done */ - if (disk_i_size >= inode->i_size || - ordered->file_offset + ordered->len <= disk_i_size) { + if (disk_i_size == i_size || offset <= disk_i_size) { goto out; } @@ -616,8 +645,7 @@ int btrfs_ordered_update_i_size(struct inode *inode, * we can't update the disk_isize if there are delalloc bytes * between disk_i_size and this ordered extent */ - if (test_range_bit(io_tree, disk_i_size, - ordered->file_offset + ordered->len - 1, + if (test_range_bit(io_tree, disk_i_size, offset - 1, EXTENT_DELALLOC, 0, NULL)) { goto out; } @@ -626,20 +654,32 @@ int btrfs_ordered_update_i_size(struct inode *inode, * if we find an ordered extent then we can't update disk i_size * yet */ - node = &ordered->rb_node; - while (1) { - node = rb_prev(node); - if (!node) - break; + if (ordered) { + node = rb_prev(&ordered->rb_node); + } else { + prev = tree_search(tree, offset); + /* + * we insert file extents without involving ordered struct, + * so there should be no ordered struct cover this offset + */ + if (prev) { + test = rb_entry(prev, struct btrfs_ordered_extent, + rb_node); + BUG_ON(offset_in_entry(test, offset)); + } + node = prev; + } + while (node) { test = rb_entry(node, struct btrfs_ordered_extent, rb_node); if (test->file_offset + test->len <= disk_i_size) break; - if (test->file_offset >= inode->i_size) + if (test->file_offset >= i_size) break; if (test->file_offset >= disk_i_size) goto out; + node = rb_prev(node); } - new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode)); + new_i_size = min_t(u64, offset, i_size); /* * at this point, we know we can safely update i_size to at least @@ -647,7 +687,14 @@ int btrfs_ordered_update_i_size(struct inode *inode, * walk forward and see if ios from higher up in the file have * finished. */ - node = rb_next(&ordered->rb_node); + if (ordered) { + node = rb_next(&ordered->rb_node); + } else { + if (prev) + node = rb_next(prev); + else + node = rb_first(&tree->tree); + } i_size_test = 0; if (node) { /* @@ -655,10 +702,10 @@ int btrfs_ordered_update_i_size(struct inode *inode, * between our ordered extent and the next one. */ test = rb_entry(node, struct btrfs_ordered_extent, rb_node); - if (test->file_offset > entry_end(ordered)) + if (test->file_offset > offset) i_size_test = test->file_offset; } else { - i_size_test = i_size_read(inode); + i_size_test = i_size; } /* @@ -667,15 +714,25 @@ int btrfs_ordered_update_i_size(struct inode *inode, * are no delalloc bytes in this area, it is safe to update * disk_i_size to the end of the region. */ - if (i_size_test > entry_end(ordered) && - !test_range_bit(io_tree, entry_end(ordered), i_size_test - 1, - EXTENT_DELALLOC, 0, NULL)) { - new_i_size = min_t(u64, i_size_test, i_size_read(inode)); + if (i_size_test > offset && + !test_range_bit(io_tree, offset, i_size_test - 1, + EXTENT_DELALLOC, 0, NULL)) { + new_i_size = min_t(u64, i_size_test, i_size); } BTRFS_I(inode)->disk_i_size = new_i_size; + ret = 0; out: + /* + * we need to remove the ordered extent with the tree lock held + * so that other people calling this function don't find our fully + * processed ordered entry and skip updating the i_size + */ + if (ordered) + __btrfs_remove_ordered_extent(inode, ordered); mutex_unlock(&tree->mutex); - return 0; + if (ordered) + wake_up(&ordered->wait); + return ret; } /* diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h index f82e87488ca8..4fa20398aec1 100644 --- a/fs/btrfs/ordered-data.h +++ b/fs/btrfs/ordered-data.h @@ -150,7 +150,7 @@ void btrfs_start_ordered_extent(struct inode *inode, int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len); struct btrfs_ordered_extent * btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset); -int btrfs_ordered_update_i_size(struct inode *inode, +int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, struct btrfs_ordered_extent *ordered); int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum); int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);