From 6a912213046ecb6511fdf35531a0c7de3de963c9 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Sat, 20 Nov 2010 09:48:00 +0000 Subject: [PATCH] Btrfs: use dget_parent where we can UPDATED There are lots of places where we do dentry->d_parent->d_inode without holding the dentry->d_lock. This could cause problems with rename. So instead we need to use dget_parent() and hold the reference to the parent as long as we are going to use it's inode and then dput it at the end. Signed-off-by: Josef Bacik Cc: raven@themaw.net Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 9 ++++++--- fs/btrfs/ioctl.c | 20 ++++++++++++++++---- fs/btrfs/transaction.c | 5 ++++- fs/btrfs/tree-log.c | 21 +++++++++++++++++---- 4 files changed, 43 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index fc22f556aa24..c0faf47d0cd9 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4811,10 +4811,12 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, if (err) { drop_inode = 1; } else { + struct dentry *parent = dget_parent(dentry); btrfs_update_inode_block_group(trans, dir); err = btrfs_update_inode(trans, root, inode); BUG_ON(err); - btrfs_log_new_name(trans, inode, NULL, dentry->d_parent); + btrfs_log_new_name(trans, inode, NULL, parent); + dput(parent); } nr = trans->blocks_used; @@ -6768,8 +6770,9 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, BUG_ON(ret); if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { - btrfs_log_new_name(trans, old_inode, old_dir, - new_dentry->d_parent); + struct dentry *parent = dget_parent(new_dentry); + btrfs_log_new_name(trans, old_inode, old_dir, parent); + dput(parent); btrfs_end_log_trans(root); } out_fail: diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 6b4bfa72bf8d..f1c9bb4079ed 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -233,7 +233,8 @@ static noinline int create_subvol(struct btrfs_root *root, struct btrfs_inode_item *inode_item; struct extent_buffer *leaf; struct btrfs_root *new_root; - struct inode *dir = dentry->d_parent->d_inode; + struct dentry *parent = dget_parent(dentry); + struct inode *dir; int ret; int err; u64 objectid; @@ -242,8 +243,13 @@ static noinline int create_subvol(struct btrfs_root *root, ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root, 0, &objectid); - if (ret) + if (ret) { + dput(parent); return ret; + } + + dir = parent->d_inode; + /* * 1 - inode item * 2 - refs @@ -251,8 +257,10 @@ static noinline int create_subvol(struct btrfs_root *root, * 2 - dir items */ trans = btrfs_start_transaction(root, 6); - if (IS_ERR(trans)) + if (IS_ERR(trans)) { + dput(parent); return PTR_ERR(trans); + } leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, objectid, NULL, 0, 0, 0); @@ -339,6 +347,7 @@ static noinline int create_subvol(struct btrfs_root *root, d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); fail: + dput(parent); if (async_transid) { *async_transid = trans->transid; err = btrfs_commit_transaction_async(trans, root, 1); @@ -354,6 +363,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, char *name, int namelen, u64 *async_transid) { struct inode *inode; + struct dentry *parent; struct btrfs_pending_snapshot *pending_snapshot; struct btrfs_trans_handle *trans; int ret; @@ -396,7 +406,9 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, btrfs_orphan_cleanup(pending_snapshot->snap); - inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry); + parent = dget_parent(dentry); + inode = btrfs_lookup_dentry(parent->d_inode, dentry); + dput(parent); if (IS_ERR(inode)) { ret = PTR_ERR(inode); goto fail; diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 1fffbc017bdf..f50e931fc217 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -902,6 +902,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root *root = pending->root; struct btrfs_root *parent_root; struct inode *parent_inode; + struct dentry *parent; struct dentry *dentry; struct extent_buffer *tmp; struct extent_buffer *old; @@ -941,7 +942,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, trans->block_rsv = &pending->block_rsv; dentry = pending->dentry; - parent_inode = dentry->d_parent->d_inode; + parent = dget_parent(dentry); + parent_inode = parent->d_inode; parent_root = BTRFS_I(parent_inode)->root; record_root_in_trans(trans, parent_root); @@ -989,6 +991,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, parent_inode->i_ino, index, dentry->d_name.name, dentry->d_name.len); BUG_ON(ret); + dput(parent); key.offset = (u64)-1; pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key); diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index a29f19384a27..054744ac5719 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -2869,6 +2869,7 @@ static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans, { int ret = 0; struct btrfs_root *root; + struct dentry *old_parent = NULL; /* * for regular files, if its inode is already on disk, we don't @@ -2910,10 +2911,13 @@ static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans, if (IS_ROOT(parent)) break; - parent = parent->d_parent; + parent = dget_parent(parent); + dput(old_parent); + old_parent = parent; inode = parent->d_inode; } + dput(old_parent); out: return ret; } @@ -2945,6 +2949,7 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, { int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL; struct super_block *sb; + struct dentry *old_parent = NULL; int ret = 0; u64 last_committed = root->fs_info->last_trans_committed; @@ -3016,10 +3021,13 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, if (IS_ROOT(parent)) break; - parent = parent->d_parent; + parent = dget_parent(parent); + dput(old_parent); + old_parent = parent; } ret = 0; end_trans: + dput(old_parent); if (ret < 0) { BUG_ON(ret != -ENOSPC); root->fs_info->last_trans_log_full_commit = trans->transid; @@ -3039,8 +3047,13 @@ end_no_trans: int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct dentry *dentry) { - return btrfs_log_inode_parent(trans, root, dentry->d_inode, - dentry->d_parent, 0); + struct dentry *parent = dget_parent(dentry); + int ret; + + ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0); + dput(parent); + + return ret; } /* -- 2.20.1