From 784b4e29a26617589edd290dd2919735e190c06e Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Sun, 21 Nov 2010 22:20:49 -0500 Subject: Btrfs: add migrate page for metadata inode Migrate page will directly call the btrfs btree writepage function, which isn't actually allowed. Our writepage assumes that you have locked the extent_buffer and flagged the block as written. Without doing these steps, we can corrupt metadata blocks. A later commit will remove the btree writepage function since it is really only safely used internally by btrfs. We use writepages for everything else. Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index b40dfe48017b..a67b98d58c2a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -28,6 +28,7 @@ #include #include #include +#include #include "compat.h" #include "ctree.h" #include "disk-io.h" @@ -355,6 +356,8 @@ static int csum_dirty_buffer(struct btrfs_root *root, struct page *page) ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE, btrfs_header_generation(eb)); BUG_ON(ret); + WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN)); + found_start = btrfs_header_bytenr(eb); if (found_start != start) { WARN_ON(1); @@ -693,6 +696,26 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, __btree_submit_bio_done); } +static int btree_migratepage(struct address_space *mapping, + struct page *newpage, struct page *page) +{ + /* + * we can't safely write a btree page from here, + * we haven't done the locking hook + */ + if (PageDirty(page)) + return -EAGAIN; + /* + * Buffers may be managed in a filesystem specific way. + * We must have no buffers or drop them. + */ + if (page_has_private(page) && + !try_to_release_page(page, GFP_KERNEL)) + return -EAGAIN; + + return migrate_page(mapping, newpage, page); +} + static int btree_writepage(struct page *page, struct writeback_control *wbc) { struct extent_io_tree *tree; @@ -707,8 +730,7 @@ static int btree_writepage(struct page *page, struct writeback_control *wbc) } redirty_page_for_writepage(wbc, page); - eb = btrfs_find_tree_block(root, page_offset(page), - PAGE_CACHE_SIZE); + eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE); WARN_ON(!eb); was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); @@ -799,6 +821,7 @@ static const struct address_space_operations btree_aops = { .releasepage = btree_releasepage, .invalidatepage = btree_invalidatepage, .sync_page = block_sync_page, + .migratepage = btree_migratepage, }; int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, -- cgit v1.2.3 From 450ba0ea06b6ed3612d27f2b7127a9de4160f285 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 19 Nov 2010 14:59:15 -0500 Subject: Btrfs: setup blank root and fs_info for mount time There is a problem with how we use sget, it searches through the list of supers attached to the fs_type looking for a super with the same fs_devices as what we're trying to mount. This depends on sb->s_fs_info being filled, but we don't fill that in until we get to btrfs_fill_super, so we could hit supers on the fs_type super list that have a null s_fs_info. In order to fix that we need to go ahead and setup a blank root with a blank fs_info to hold fs_devices, that way our test will work out right and then we can set s_fs_info in btrfs_set_super, and then open_ctree will simply use our pre-allocated root and fs_info when setting everything up. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index a67b98d58c2a..57c9d8eeb7dc 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1561,10 +1561,8 @@ struct btrfs_root *open_ctree(struct super_block *sb, GFP_NOFS); struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); - struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root), - GFP_NOFS); - struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info), - GFP_NOFS); + struct btrfs_root *tree_root = btrfs_sb(sb); + struct btrfs_fs_info *fs_info = tree_root->fs_info; struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root), -- cgit v1.2.3 From 5a92bc88cef279261d3f138e25850c122df67045 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 29 Nov 2010 09:49:11 -0500 Subject: Btrfs: don't use migrate page without CONFIG_MIGRATION Fixes compile error Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 57c9d8eeb7dc..33b6d459494c 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -712,8 +712,11 @@ static int btree_migratepage(struct address_space *mapping, if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return -EAGAIN; - +#ifdef CONFIG_MIGRATION return migrate_page(mapping, newpage, page); +#else + return -ENOSYS; +#endif } static int btree_writepage(struct page *page, struct writeback_control *wbc) @@ -821,7 +824,9 @@ static const struct address_space_operations btree_aops = { .releasepage = btree_releasepage, .invalidatepage = btree_invalidatepage, .sync_page = block_sync_page, +#ifdef CONFIG_MIGRATION .migratepage = btree_migratepage, +#endif }; int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, -- cgit v1.2.3 From 3dd1462e82bcab7625cec129952f26dae7a8b742 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 7 Dec 2010 14:54:09 +0000 Subject: Btrfs: fix compiler warnings ... regarding an unused function when !MIGRATION, and regarding a printk() format string vs argument mismatch. Signed-off-by: Jan Beulich Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 33b6d459494c..b803c2667673 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -696,6 +696,7 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, __btree_submit_bio_done); } +#ifdef CONFIG_MIGRATION static int btree_migratepage(struct address_space *mapping, struct page *newpage, struct page *page) { @@ -712,12 +713,9 @@ static int btree_migratepage(struct address_space *mapping, if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return -EAGAIN; -#ifdef CONFIG_MIGRATION return migrate_page(mapping, newpage, page); -#else - return -ENOSYS; -#endif } +#endif static int btree_writepage(struct page *page, struct writeback_control *wbc) { -- cgit v1.2.3 From 68433b73b104bff388aac376631d32abbbd872b0 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 13 Dec 2010 14:47:58 -0500 Subject: Btrfs: EIO when we fail to read tree roots If we just get a plain IO error when we read tree roots, the code wasn't properly sending that error up the chain. This allowed mounts to continue when they should failed, and allowed operations on partially setup root structs. The end result was usually oopsen on spinlocks that hadn't been spun up correctly. Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index b803c2667673..a5d2249e6da5 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1007,7 +1007,10 @@ static int find_and_setup_root(struct btrfs_root *tree_root, blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), blocksize, generation); - BUG_ON(!root->node); + if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) { + free_extent_buffer(root->node); + return -EIO; + } root->commit_root = btrfs_root_node(root); return 0; } -- cgit v1.2.3