From f1ca7e98a67da618d8595866e0860308525154da Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Sat, 29 Jun 2013 23:15:19 -0400 Subject: [PATCH] Btrfs: hold the tree mod lock in __tree_mod_log_rewind We need to hold the tree mod log lock in __tree_mod_log_rewind since we walk forward in the tree mod entries, otherwise we'll end up with random entries and trip the BUG_ON() at the front of __tree_mod_log_rewind. This fixes the panics people were seeing when running find /whatever -type f -exec btrfs fi defrag {} \; Thansk, Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik --- fs/btrfs/ctree.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index c32d03d..7921e1d 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1161,8 +1161,8 @@ __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, * time_seq). */ static void -__tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, - struct tree_mod_elem *first_tm) +__tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, + u64 time_seq, struct tree_mod_elem *first_tm) { u32 n; struct rb_node *next; @@ -1172,6 +1172,7 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, unsigned long p_size = sizeof(struct btrfs_key_ptr); n = btrfs_header_nritems(eb); + tree_mod_log_read_lock(fs_info); while (tm && tm->seq >= time_seq) { /* * all the operations are recorded with the operator used for @@ -1226,6 +1227,7 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, if (tm->index != first_tm->index) break; } + tree_mod_log_read_unlock(fs_info); btrfs_set_header_nritems(eb, n); } @@ -1274,7 +1276,7 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, extent_buffer_get(eb_rewin); btrfs_tree_read_lock(eb_rewin); - __tree_mod_log_rewind(eb_rewin, time_seq, tm); + __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); WARN_ON(btrfs_header_nritems(eb_rewin) > BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root)); @@ -1350,7 +1352,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq) btrfs_set_header_generation(eb, old_generation); } if (tm) - __tree_mod_log_rewind(eb, time_seq, tm); + __tree_mod_log_rewind(root->fs_info, eb, time_seq, tm); else WARN_ON(btrfs_header_level(eb) != 0); WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); -- 2.7.4