BMC/Intel-BMC/linux.git/fs/btrfs/delayed-inode.c, branch dev

Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.

2015-04-26T13:27:03+00:00

We need to fill inode when we found a node for it in delayed_nodes_tree. But we did not fill the ->last_trans currently, it will cause the test of xfstest/generic/311 fail. Scenario of the 311 is shown as below: Problem: (1). test_fd = open(fname, O_RDWR|O_DIRECT) (2). pwrite(test_fd, buf, 4096, 0) (3). close(test_fd) (4). drop_all_caches() <-------- "echo 3 > /proc/sys/vm/drop_caches" (5). test_fd = open(fname, O_RDWR|O_DIRECT) (6). fsync(test_fd); <-------- we did not get the correct log entry for the file Reason: When we re-open this file in (5), we would find a node in delayed_nodes_tree and fill the inode we are lookup with the information. But the ->last_trans is not filled, then the fsync() will check the ->last_trans and found it's 0 then say this inode is already in our tree which is commited, not recording the extents for it. Fix: This patch fill the ->last_trans properly and set the runtime_flags if needed in this situation. Then we can get the log entries we expected after (6) and generic/311 passed. Signed-off-by: Dongsheng Yang Reviewed-by: Miao Xie Signed-off-by: Chris Mason

Btrfs: delayed-inode: replace root args iff only fs_info used

2015-02-16T17:48:43+00:00

This is the second independent patch of a larger project to cleanup btrfs's internal usage of btrfs_root. Many functions take btrfs_root only to grab the fs_info struct. By requiring a root these functions cause programmer overhead. That these functions can accept any valid root is not obvious until inspection. This patch reduces the specificity of such functions to accept the fs_info directly. These patches can be applied independently and thus are not being submitted as a patch series. There should be about 26 patches by the project's completion. Each patch will cleanup between 1 and 34 functions apiece. Each patch covers a single file's functions. This patch affects the following function(s): 1) btrfs_wq_run_delayed_node Signed-off-by: Daniel Dressler Signed-off-by: David Sterba

Btrfs: Add code to support file creation time

2015-02-03T02:39:16+00:00

This patch adds a new member to the 'struct btrfs_inode' structure to hold the file creation time. Signed-off-by: chandan [refreshed, removed btrfs_inode_otime] Signed-off-by: David Sterba Signed-off-by: Chris Mason

btrfs: kill btrfs_inode_*time helpers

2015-02-03T02:39:07+00:00

They just opencode taking address of the timespec member. Signed-off-by: David Sterba Signed-off-by: Chris Mason

Btrfs: don't delay inode ref updates during log replay

2015-01-02T19:47:56+00:00

Commit 1d52c78afbb (Btrfs: try not to ENOSPC on log replay) added a check to skip delayed inode updates during log replay because it confuses the enospc code. But the delayed processing will end up ignoring delayed refs from log replay because the inode itself wasn't put through the delayed code. This can end up triggering a warning at commit time: WARNING: CPU: 2 PID: 778 at fs/btrfs/delayed-inode.c:1410 btrfs_assert_delayed_root_empty+0x32/0x34() Which is repeated for each commit because we never process the delayed inode ref update. The fix used here is to change btrfs_delayed_delete_inode_ref to return an error if we're currently in log replay. The caller will do the ref deletion immediately and everything will work properly. Signed-off-by: Chris Mason cc: stable@vger.kernel.org # v3.18 and any stable series that picked 1d52c78afbbf80b58299e076a159617d6b42fe3c

btrfs: kill the key type accessor helpers

2014-09-17T20:37:12+00:00

btrfs_set_key_type and btrfs_key_type are used inconsistently along with open coded variants. Other members of btrfs_key are accessed directly without any helpers anyway. Signed-off-by: David Sterba Signed-off-by: Chris Mason

Btrfs: fix task hang under heavy compressed write

2014-08-24T14:17:02+00:00

This has been reported and discussed for a long time, and this hang occurs in both 3.15 and 3.16. Btrfs now migrates to use kernel workqueue, but it introduces this hang problem. Btrfs has a kind of work queued as an ordered way, which means that its ordered_func() must be processed in the way of FIFO, so it usually looks like -- normal_work_helper(arg) work = container_of(arg, struct btrfs_work, normal_work); work->func() <---- (we name it work X) for ordered_work in wq->ordered_list ordered_work->ordered_func() ordered_work->ordered_free() The hang is a rare case, first when we find free space, we get an uncached block group, then we go to read its free space cache inode for free space information, so it will file a readahead request btrfs_readpages() for page that is not in page cache __do_readpage() submit_extent_page() btrfs_submit_bio_hook() btrfs_bio_wq_end_io() submit_bio() end_workqueue_bio() <--(ret by the 1st endio) queue a work(named work Y) for the 2nd also the real endio() So the hang occurs when work Y's work_struct and work X's work_struct happens to share the same address. A bit more explanation, A,B,C -- struct btrfs_work arg -- struct work_struct kthread: worker_thread() pick up a work_struct from @worklist process_one_work(arg) worker->current_work = arg; <-- arg is A->normal_work worker->current_func(arg) normal_work_helper(arg) A = container_of(arg, struct btrfs_work, normal_work); A->func() A->ordered_func() A->ordered_free() <-- A gets freed B->ordered_func() submit_compressed_extents() find_free_extent() load_free_space_inode() ... <-- (the above readhead stack) end_workqueue_bio() btrfs_queue_work(work C) B->ordered_free() As if work A has a high priority in wq->ordered_list and there are more ordered works queued after it, such as B->ordered_func(), its memory could have been freed before normal_work_helper() returns, which means that kernel workqueue code worker_thread() still has worker->current_work pointer to be work A->normal_work's, ie. arg's address. Meanwhile, work C is allocated after work A is freed, work C->normal_work and work A->normal_work are likely to share the same address(I confirmed this with ftrace output, so I'm not just guessing, it's rare though). When another kthread picks up work C->normal_work to process, and finds our kthread is processing it(see find_worker_executing_work()), it'll think work C as a collision and skip then, which ends up nobody processing work C. So the situation is that our kthread is waiting forever on work C. Besides, there're other cases that can lead to deadlock, but the real problem is that all btrfs workqueue shares one work->func, -- normal_work_helper, so this makes each workqueue to have its own helper function, but only a wraper pf normal_work_helper. With this patch, I no long hit the above hang. Signed-off-by: Liu Bo Signed-off-by: Chris Mason

btrfs: free delayed node outside of root->inode_lock

2014-06-10T00:21:08+00:00

On heavy workloads, we're seeing soft lockup warnings on root->inode_lock in __btrfs_release_delayed_node. The low hanging fruit is to reduce the size of the critical section. Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: Chris Mason

btrfs: Cleanup the "_struct" suffix in btrfs_workequeue

2014-03-10T19:17:16+00:00

Since the "_struct" suffix is mainly used for distinguish the differnt btrfs_work between the original and the newly created one, there is no need using the suffix since all btrfs_workers are changed into btrfs_workqueue. Also this patch fixed some codes whose code style is changed due to the too long "_struct" suffix. Signed-off-by: Qu Wenruo Tested-by: David Sterba Signed-off-by: Josef Bacik

btrfs: Replace fs_info->delayed_workers workqueue with btrfs_workqueue.

2014-03-10T19:17:12+00:00

Replace the fs_info->delayed_workers with the newly created btrfs_workqueue. Signed-off-by: Qu Wenruo Tested-by: David Sterba Signed-off-by: Josef Bacik