This patch fixes the following deadlock bug during the recovery.
INFO: task mount:1322 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mount D ffffffff81125870 0 1322 1266 0x00000000
ffff8801207e39d8 0000000000000046 ffff88012ab1dee0 0000000000000046
ffff8801207e3a08 ffff880115903f40 ffff8801207e3fd8 ffff8801207e3fd8
ffff8801207e3fd8 ffff880115903f40 ffff8801207e39d8 ffff88012fc94520
Call Trace:
[<ffffffff81125870>] ? __lock_page+0x70/0x70
[<ffffffff816a92d9>] schedule+0x29/0x70
[<ffffffff816a93af>] io_schedule+0x8f/0xd0
[<ffffffff8112587e>] sleep_on_page+0xe/0x20
[<ffffffff816a649a>] __wait_on_bit_lock+0x5a/0xc0
[<ffffffff81125867>] __lock_page+0x67/0x70
[<ffffffff8106c7b0>] ? autoremove_wake_function+0x40/0x40
[<ffffffff81126857>] find_lock_page+0x67/0x80
[<ffffffff8112698f>] find_or_create_page+0x3f/0xb0
[<ffffffffa03901a8>] ? sync_inode_page+0xa8/0xd0 [f2fs]
[<ffffffffa038fdf7>] get_node_page+0x67/0x180 [f2fs]
[<ffffffffa039818b>] recover_fsync_data+0xacb/0xff0 [f2fs]
[<ffffffff816aaa1e>] ? _raw_spin_unlock+0x3e/0x40
[<ffffffffa0389634>] f2fs_fill_super+0x7d4/0x850 [f2fs]
[<ffffffff81184cf9>] mount_bdev+0x1c9/0x210
[<ffffffffa0388e60>] ? validate_superblock+0x180/0x180 [f2fs]
[<ffffffffa0387635>] f2fs_mount+0x15/0x20 [f2fs]
[<ffffffff81185a13>] mount_fs+0x43/0x1b0
[<ffffffff81145ba0>] ? __alloc_percpu+0x10/0x20
[<ffffffff811a0796>] vfs_kern_mount+0x76/0x120
[<ffffffff811a2cb7>] do_mount+0x237/0xa10
[<ffffffff81140b9b>] ? strndup_user+0x5b/0x80
[<ffffffff811a3520>] SyS_mount+0x90/0xe0
[<ffffffff816b3502>] system_call_fastpath+0x16/0x1b
The bug is triggered when check_index_in_prev_nodes tries to get the direct
node page by calling get_node_page.
At this point, if the direct node page is already locked by get_dnode_of_data,
its caller, we got a deadlock condition.
This patch adds additional condition check for the reuse of locked direct node
pages prior to the get_node_page call.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Few things can be changed in the default mkwrite function
1) Make file_update_time at the start before acquiring any lock
2) the condition page_offset(page) >= i_size_read(inode) should be
changed to page_offset(page) > i_size_read
3) Move wait_on_page_writeback.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch-set includes the following major enhancement patches.
o introduce a new gloabl lock scheme
o add tracepoints on several major functions
o fix the overall cleaning process focused on victim selection
o apply the block plugging to merge IOs as much as possible
o enhance management of free nids and its list
o enhance the readahead mode for node pages
o address several cretical deadlock conditions
o reduce lock_page calls
The other minor bug fixes and enhancements are as follows.
o calculation mistakes: overflow
o bio types: READ, READA, and READ_SYNC
o fix the recovery flow, data races, and null pointer errors
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Merge tag 'f2fs-for-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"This patch-set includes the following major enhancement patches.
- introduce a new gloabl lock scheme
- add tracepoints on several major functions
- fix the overall cleaning process focused on victim selection
- apply the block plugging to merge IOs as much as possible
- enhance management of free nids and its list
- enhance the readahead mode for node pages
- address several cretical deadlock conditions
- reduce lock_page calls
The other minor bug fixes and enhancements are as follows.
- calculation mistakes: overflow
- bio types: READ, READA, and READ_SYNC
- fix the recovery flow, data races, and null pointer errors"
* tag 'f2fs-for-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (68 commits)
f2fs: cover free_nid management with spin_lock
f2fs: optimize scan_nat_page()
f2fs: code cleanup for scan_nat_page() and build_free_nids()
f2fs: bugfix for alloc_nid_failed()
f2fs: recover when journal contains deleted files
f2fs: continue to mount after failing recovery
f2fs: avoid deadlock during evict after f2fs_gc
f2fs: modify the number of issued pages to merge IOs
f2fs: remove useless #include <linux/proc_fs.h> as we're now using sysfs as debug entry.
f2fs: fix inconsistent using of NM_WOUT_THRESHOLD
f2fs: check truncation of mapping after lock_page
f2fs: enhance alloc_nid and build_free_nids flows
f2fs: add a tracepoint on f2fs_new_inode
f2fs: check nid == 0 in add_free_nid
f2fs: add REQ_META about metadata requests for submit
f2fs: give a chance to merge IOs by IO scheduler
f2fs: avoid frequent background GC
f2fs: add tracepoints to debug checkpoint request
f2fs: add tracepoints for write page operations
f2fs: add tracepoints to debug the block allocation
...
We call lock_page when we need to update a page after readpage.
Between grab and lock page, the page can be truncated by other thread.
So, we should check the page after lock_page whether it was truncated or not.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
add tracepoints for tracing the truncate operations
like truncate node/data blocks, f2fs_truncate etc.
Tracepoints are added at entry and exit of operation
to trace the success & failure of operation.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
[Jaegeuk: combine and modify the tracepoint structures]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Add tracepoints in f2fs for tracing the syncing
operations like filesystem sync, file sync enter/exit.
It will helf to trace the code under debugging scenarios.
Also add tracepoints for tracing the various inode operations
like building inode, eviction of inode, link/unlike of
inodes.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
[Jaegeuk: combine and modify the tracepoint structures]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
In the previous version, f2fs uses global locks according to the usage types,
such as directory operations, block allocation, block write, and so on.
Reference the following lock types in f2fs.h.
enum lock_type {
RENAME, /* for renaming operations */
DENTRY_OPS, /* for directory operations */
DATA_WRITE, /* for data write */
DATA_NEW, /* for data allocation */
DATA_TRUNC, /* for data truncate */
NODE_NEW, /* for node allocation */
NODE_TRUNC, /* for node truncate */
NODE_WRITE, /* for node write */
NR_LOCK_TYPE,
};
In that case, we lose the performance under the multi-threading environment,
since every types of operations must be conducted one at a time.
In order to address the problem, let's share the locks globally with a mutex
array regardless of any types.
So, let users grab a mutex and perform their jobs in parallel as much as
possbile.
For this, I propose a new global lock scheme as follows.
0. Data structure
- f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS]
- f2fs_sb_info -> node_write
1. mutex_lock_op(sbi)
- try to get an avaiable lock from the array.
- returns the index of the gottern lock variable.
2. mutex_unlock_op(sbi, index of the lock)
- unlock the given index of the lock.
3. mutex_lock_all(sbi)
- grab all the locks in the array before the checkpoint.
4. mutex_unlock_all(sbi)
- release all the locks in the array after checkpoint.
5. block_operations()
- call mutex_lock_all()
- sync_dirty_dir_inodes()
- grab node_write
- sync_node_pages()
Note that,
the pairs of mutex_lock_op()/mutex_unlock_op() and
mutex_lock_all()/mutex_unlock_all() should be used together.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Move the f2fs_balance_fs out of the truncate_hole function and only
perform that in punch_hole use case. The commit:
ed60b1644e7f7e5dd67d21caf7e4425dff05dad0
intended to do this but moved it into truncate_hole to cover more
cases. However, a deadlock scenario is possible when deleting an inode
entry under specific conditions:
f2fs_delete_entry()
mutex_lock_op(sbi, DENTRY_OPS);
truncate_hole()
f2fs_balance_fs()
mutex_lock(&sbi->gc_mutex);
f2fs_gc()
write_checkpoint()
block_operations()
mutex_lock_op(sbi, DENTRY_OPS);
Lets move it into the punch_hole case to cover the original intent of
avoiding it during fallocate's expand_inode_data case.
Change-Id: I29f8ea1056b0b88b70ba8652d901b6e8431bb27e
Signed-off-by: Jason Hrycay <jason.hrycay@motorola.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
When we recover fsync'ed data after power-off-recovery, we should guarantee
that any parent inode number should be correct for each direct inode blocks.
So, let's make the following rules.
- The fsync should do checkpoint to all the inodes that were experienced hard
links.
- So, the only normal files can be recovered by roll-forward.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch removes data_version check flow during the fsync call.
The original purpose for the use of data_version was to avoid writng inode
pages redundantly by the fsync calls repeatedly.
However, when user can modify file meta and then call fsync, we should not
skip fsync procedure.
So, let's remove this condition check and hope that user triggers in right
manner.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The fsync call should be ended after flushing the in-device caches.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Previously, f2fs reads several node pages ahead when get_dnode_of_data is called
with RDONLY_NODE flag.
And, this flag is set by the following functions.
- get_data_block_ro
- get_lock_data_page
- do_write_data_page
- truncate_blocks
- truncate_hole
However, this readahead mechanism is initially introduced for the use of
get_data_block_ro to enhance the sequential read performance.
So, let's clarify all the cases with the additional modes as follows.
enum {
ALLOC_NODE, /* allocate a new node page if needed */
LOOKUP_NODE, /* look up a node without readahead */
LOOKUP_NODE_RA, /*
* look up a node with readahead called
* by get_datablock_ro.
*/
}
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
adding compat_ioctl to provide support for backward comptability - 32bit binary
execution on 64bit kernel.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
1. Background
Previously, if f2fs tries to move data blocks of an *evicting* inode during the
cleaning process, it stops the process incompletely and then restarts the whole
process, since it needs a locked inode to grab victim data pages in its address
space. In order to get a locked inode, iget_locked() by f2fs_iget() is normally
used, but, it waits if the inode is on freeing.
So, here is a deadlock scenario.
1. f2fs_evict_inode() <- inode "A"
2. f2fs_balance_fs()
3. f2fs_gc()
4. gc_data_segment()
5. f2fs_iget() <- inode "A" too!
If step #1 and #5 treat a same inode "A", step #5 would fall into deadlock since
the inode "A" is on freeing. In order to resolve this, f2fs_iget_nowait() which
skips __wait_on_freeing_inode() was introduced in step #5, and stops f2fs_gc()
to complete f2fs_evict_inode().
1. f2fs_evict_inode() <- inode "A"
2. f2fs_balance_fs()
3. f2fs_gc()
4. gc_data_segment()
5. f2fs_iget_nowait() <- inode "A", then stop f2fs_gc() w/ -ENOENT
2. Problem and Solution
In the above scenario, however, f2fs cannot finish f2fs_evict_inode() only if:
o there are not enough free sections, and
o f2fs_gc() tries to move data blocks of the *evicting* inode repeatedly.
So, the final solution is to use f2fs_iget() and remove f2fs_balance_fs() in
f2fs_evict_inode().
The f2fs_evict_inode() actually truncates all the data and node blocks, which
means that it doesn't produce any dirty node pages accordingly.
So, we don't need to do f2fs_balance_fs() in practical.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The fill_zero() from fallocate() calls get_new_data_page() in which calls
reserve_new_block().
The reserve_new_block() should be covered by *DATA_NEW*, one of global locks.
And also, before getting the lock, we should check free sections by calling
f2fs_balance_fs().
If we break this rule, f2fs is able to face with out-of-control free space
management and fall into infinite loop like the following scenario as well.
[f2fs_sync_fs()] [fallocate()]
- write_checkpoint() - fill_zero()
- block_operations() - get_new_data_page()
: grab NODE_NEW - get_dnode_of_data()
: get locked dirty node page
- sync_node_pages()
: try to grab NODE_NEW for data allocation
: trylock and skip the dirty node page
: call sync_node_pages() repeatedly in order to flush all the dirty node
pages!
In order to avoid this, we should grab another global lock such as DATA_NEW
before calling get_new_data_page() in fill_zero().
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This was added for all the file systems before.
See the following commit.
commit id: 0b173bc4da
[PATCH] mm: kill vma flag VM_CAN_NONLINEAR
This patch moves actual ptes filling for non-linear file mappings
into special vma operation: ->remap_pages().
File system must implement this method to get non-linear mappings support,
if it uses filemap_fault() then generic_file_remap_pages() can be used.
Now device drivers can implement this method and obtain nonlinear vma support."
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The f2fs_fallocate() has two operations: punch_hole and expand_size.
Only in the case of punch_hole, dirty node pages can be produced, so let's
trigger f2fs_balance_fs() in this case only.
Furthermore, let's trigger it at every data truncation routine.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The f2fs_balance_fs() is to check the number of free sections and decide whether
it needs to conduct cleaning or not. If there are not enough free sections, the
cleaning job should be started.
In order to control an amount of free sections even under high utilization, f2fs
should call f2fs_balance_fs at all the VFS interfaces that are able to produce
dirty pages.
This patch adds the function calls in the missing interfaces as follows.
1. f2fs_setxattr()
The f2fs_setxattr() produces dirty node pages so that we should call
f2fs_balance_fs() either likewise doing in other VFS interfaces such as
f2fs_lookup(), f2fs_mkdir(), and so on.
2. f2fs_sync_file()
We should guarantee serving free sections for syncing metadata during fsync.
Previously, there is no space check before triggering checkpoint and
sync_node_pages.
Therefore, if a bunch of fsync calls are triggered under 100% of FS utilization,
f2fs is able to be faced with no free sections, resulting in BUG_ON().
3. f2fs_sync_fs()
Before calling write_checkpoint(), we should guarantee that there are minimum
free sections.
4. f2fs_write_inode()
f2fs_write_inode() is also able to produce dirty node pages.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
After doing a punch hole or expanding inode doing fallocation.
The change and modification time are not update for the file.
So, update time after no issue is observed in fallocate.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Ruslan reported that f2fs hangs with an infinite loop in f2fs_sync_file():
while (sync_node_pages(sbi, inode->i_ino, &wbc) == 0)
f2fs_write_inode(inode, NULL);
The reason was revealed that the cold flag is not set even thought this inode is
a normal file. Therefore, sync_node_pages() skips to write node blocks since it
only writes cold node blocks.
The cold flag is stored to the node_footer in node block, and whenever a new
node page is allocated, it is set according to its file type, file or directory.
But, after sudden-power-off, when recovering the inode page, f2fs doesn't recover
its cold flag.
So, let's assign the cold flag in more right places.
One more thing:
If f2fs_write_inode() returns an error due to whatever situations, there would
be no dirty node pages so that sync_node_pages() returns zero.
(i.e., zero means nothing was written.)
Reported-by: Ruslan N. Marchenko <me@ruff.mobi>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The variables node_page and page_offset are initialized but never used
otherwise, so remove those unused variables.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
If the filesystem is mounted as read-only then return from that point itself
instead of first doing a writeout/wait and then checking for read-only
condition.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This adds memory operations and file/file_inode operations.
- F2FS supports fallocate(), mmap(), fsync(), and basic ioctl().
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
