From 1c8f52a5e9539600543347bcdefafa1854e07986 Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Tue, 19 Jun 2012 07:42:25 -0600 Subject: Btrfs: introduce btrfs_next_old_item We introduce btrfs_next_old_item that uses btrfs_next_old_leaf instead of btrfs_next_leaf. btrfs_next_item is also changed to simply call btrfs_next_old_item with time_seq being 0. Signed-off-by: Alexander Block Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index db15e9e7b91..84ac723f58f 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2755,13 +2755,18 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path); int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq); -static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p) +static inline int btrfs_next_old_item(struct btrfs_root *root, + struct btrfs_path *p, u64 time_seq) { ++p->slots[0]; if (p->slots[0] >= btrfs_header_nritems(p->nodes[0])) - return btrfs_next_leaf(root, p); + return btrfs_next_old_leaf(root, p, time_seq); return 0; } +static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p) +{ + return btrfs_next_old_item(root, p, 0); +} int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path); int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf); int __must_check btrfs_drop_snapshot(struct btrfs_root *root, -- cgit v1.2.3-70-g09d2 From 69bca40d41c613927b150c5392505f1894fe3010 Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Tue, 19 Jun 2012 07:42:26 -0600 Subject: Btrfs: don't assume to be on the correct extent in add_all_parents add_all_parents did assume that path is already at a correct extent data item, which may not be true in case of data extents that were partly rewritten and splitted. We need to check if we're on a matching extent for every item and only for the ones after the first. The loop is changed to do this now. This patch also fixes a bug introduced with commit 3b127fd8 "Btrfs: remove obsolete btrfs_next_leaf call from __resolve_indirect_ref". The removal of next_leaf did sometimes result in slot==nritems when the above described case happens, and thus resulting in invalid values (e.g. wanted_obejctid) in add_all_parents (leading to missed backrefs or even crashes). Signed-off-by: Alexander Block Signed-off-by: Jan Schmidt Signed-off-by: Chris Mason --- fs/btrfs/backref.c | 94 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 52 insertions(+), 42 deletions(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 8f7d1237b7a..7301cdb4b2c 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -179,61 +179,74 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id, static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, struct ulist *parents, int level, - struct btrfs_key *key, u64 time_seq, + struct btrfs_key *key_for_search, u64 time_seq, u64 wanted_disk_byte, const u64 *extent_item_pos) { - int ret; - int slot = path->slots[level]; - struct extent_buffer *eb = path->nodes[level]; + int ret = 0; + int slot; + struct extent_buffer *eb; + struct btrfs_key key; struct btrfs_file_extent_item *fi; struct extent_inode_elem *eie = NULL; u64 disk_byte; - u64 wanted_objectid = key->objectid; -add_parent: - if (level == 0 && extent_item_pos) { - fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); - ret = check_extent_in_eb(key, eb, fi, *extent_item_pos, &eie); + if (level != 0) { + eb = path->nodes[level]; + ret = ulist_add(parents, eb->start, 0, GFP_NOFS); if (ret < 0) return ret; - } - ret = ulist_add(parents, eb->start, (unsigned long)eie, GFP_NOFS); - if (ret < 0) - return ret; - - if (level != 0) return 0; + } /* - * if the current leaf is full with EXTENT_DATA items, we must - * check the next one if that holds a reference as well. - * ref->count cannot be used to skip this check. - * repeat this until we don't find any additional EXTENT_DATA items. + * We normally enter this function with the path already pointing to + * the first item to check. But sometimes, we may enter it with + * slot==nritems. In that case, go to the next leaf before we continue. */ - while (1) { - eie = NULL; + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) ret = btrfs_next_old_leaf(root, path, time_seq); - if (ret < 0) - return ret; - if (ret) - return 0; + while (!ret) { eb = path->nodes[0]; - for (slot = 0; slot < btrfs_header_nritems(eb); ++slot) { - btrfs_item_key_to_cpu(eb, key, slot); - if (key->objectid != wanted_objectid || - key->type != BTRFS_EXTENT_DATA_KEY) - return 0; - fi = btrfs_item_ptr(eb, slot, - struct btrfs_file_extent_item); - disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); - if (disk_byte == wanted_disk_byte) - goto add_parent; + slot = path->slots[0]; + + btrfs_item_key_to_cpu(eb, &key, slot); + + if (key.objectid != key_for_search->objectid || + key.type != BTRFS_EXTENT_DATA_KEY) + break; + + fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); + disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); + + if (disk_byte == wanted_disk_byte) { + eie = NULL; + if (extent_item_pos) { + ret = check_extent_in_eb(&key, eb, fi, + *extent_item_pos, + &eie); + if (ret < 0) + break; + } + if (!ret) { + ret = ulist_add(parents, eb->start, + (unsigned long)eie, GFP_NOFS); + if (ret < 0) + break; + if (!extent_item_pos) { + ret = btrfs_next_old_leaf(root, path, + time_seq); + continue; + } + } } + ret = btrfs_next_old_item(root, path, time_seq); } - return 0; + if (ret > 0) + ret = 0; + return ret; } /* @@ -250,7 +263,6 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, struct btrfs_path *path; struct btrfs_root *root; struct btrfs_key root_key; - struct btrfs_key key = {0}; struct extent_buffer *eb; int ret = 0; int root_level; @@ -295,11 +307,9 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, goto out; } - if (level == 0) - btrfs_item_key_to_cpu(eb, &key, path->slots[0]); - - ret = add_all_parents(root, path, parents, level, &key, time_seq, - ref->wanted_disk_byte, extent_item_pos); + ret = add_all_parents(root, path, parents, level, &ref->key_for_search, + time_seq, ref->wanted_disk_byte, + extent_item_pos); out: btrfs_free_path(path); return ret; -- cgit v1.2.3-70-g09d2 From e18fca734278784bd6591de63ca148cc27344ca9 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 18 Jun 2012 07:23:18 -0600 Subject: Btrfs: add a missing spin_lock When fixing up the locking in the delayed ref destruction work I accidently broke the locking myself ;(. Add back a spin_lock that should be there and we are now all set. Thanks, Btrfs: add a missing spin_lock When fixing up the locking in the delayed ref destruction work I accidently broke the locking myself ;(. Add back a spin_lock that should be there and we are now all set. Thanks, Reported-by: Dan Carpenter Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index e22c5bbf022..7d7bc8eace8 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3426,6 +3426,7 @@ int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, mutex_unlock(&head->mutex); btrfs_put_delayed_ref(ref); + spin_lock(&delayed_refs->lock); continue; } -- cgit v1.2.3-70-g09d2 From cb77fcd88569cd2b7b25ecd4086ea932a53be9b3 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 15 Jun 2012 12:19:48 -0600 Subject: Btrfs: delay iput with async extents There is some concern that these iput()'s could be the final iputs and could induce lockups on people waiting on writeback. This would happen in the rare case that we don't create ordered extents because of an error, but it is theoretically possible and we already have a mechanism to deal with this so just make them delayed iputs to negate any worry. Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 3f2c8cbe5ba..4a4f2d59a64 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -987,7 +987,7 @@ static noinline void async_cow_start(struct btrfs_work *work) async_cow->start, async_cow->end, async_cow, &num_added); if (num_added == 0) { - iput(async_cow->inode); + btrfs_add_delayed_iput(async_cow->inode); async_cow->inode = NULL; } } @@ -1023,7 +1023,7 @@ static noinline void async_cow_free(struct btrfs_work *work) struct async_cow *async_cow; async_cow = container_of(work, struct async_cow, work); if (async_cow->inode) - iput(async_cow->inode); + btrfs_add_delayed_iput(async_cow->inode); kfree(async_cow); } -- cgit v1.2.3-70-g09d2