On 18.04.19 г. 17:07 ч., Josef Bacik wrote:
> On Thu, Apr 18, 2019 at 03:50:00PM +0300, Nikolay Borisov wrote:
>>
>>
>> On 18.04.19 г. 14:06 ч., Pan Bian wrote:
>>> The reference count of inode is incremented by ihold. It should be
>>> dropped if not used. However, the reference count is not dropped if
>>> error occurs during updating the inode or deleting orphan items. This
>>> patch fixes the bug.
>>>
>>> Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
>>> ---
>>> V2: move ihold just before device_initialize to make code clearer
>>> ---
>>> fs/btrfs/inode.c | 54 +++++++++++++++++++++++++-----------------------------
>>> 1 file changed, 25 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
>>> index 82fdda8..d6630df 100644
>>> --- a/fs/btrfs/inode.c
>>> +++ b/fs/btrfs/inode.c
>>> @@ -6579,7 +6579,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
>>> struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
>>> u64 index;
>>> int err;
>>> - int drop_inode = 0;
>>> + int log_mode;
>>>
>>> /* do not allow sys_link's with other subvols of the same device */
>>> if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
>>> @@ -6616,41 +6616,37 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
>>> err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
>>> 1, index);
>>>
>>> - if (err) {
>>> - drop_inode = 1;
>>> - } else {
>>> - struct dentry *parent = dentry->d_parent;
>>> - int ret;
>>> + if (err)
>>> + goto err_link;
>>>
>>> - err = btrfs_update_inode(trans, root, inode);
>>> + err = btrfs_update_inode(trans, root, inode);
>>> + if (err)
>>> + goto err_link;
>>> + if (inode->i_nlink == 1) {
>>> + /*
>>> + * If new hard link count is 1, it's a file created
>>> + * with open(2) O_TMPFILE flag.
>>> + */
>>> + err = btrfs_orphan_del(trans, BTRFS_I(inode));
>>> if (err)
>>> - goto fail;
>>> - if (inode->i_nlink == 1) {
>>> - /*
>>> - * If new hard link count is 1, it's a file created
>>> - * with open(2) O_TMPFILE flag.
>>> - */
>>> - err = btrfs_orphan_del(trans, BTRFS_I(inode));
>>> - if (err)
>>> - goto fail;
>>> - }
>>> - BTRFS_I(inode)->last_link_trans = trans->transid;
>>> - d_instantiate(dentry, inode);
>>> - ret = btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent,
>>> - true, NULL);
>>> - if (ret == BTRFS_NEED_TRANS_COMMIT) {
>>> - err = btrfs_commit_transaction(trans);
>>> - trans = NULL;
>>> - }
>>> + goto err_link;
>>> + }
>>> + BTRFS_I(inode)->last_link_trans = trans->transid;
>>> + ihold(inode);
>
> Where is the iput for this ihold?
This ihold is sort of "given" to the d_instantiate. I.e the iput happens
when the respective dentry is unhashed/removed.
>
> Josef
>
