| Message ID | 20220503083637.1051023-2-nborisov@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Refactor btrfs_ioctl_balance | expand |
Hi Nikolay,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on kdave/for-next]
[also build test WARNING on v5.18-rc5 next-20220503]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Nikolay-Borisov/Refactor-btrfs_ioctl_balance/20220503-163837
base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next
config: mips-allyesconfig (https://download.01.org/0day-ci/archive/20220503/202205031820.eWTnmpgQ-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/d383145190e87f46bc73d86059724df2b3af9720
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Nikolay-Borisov/Refactor-btrfs_ioctl_balance/20220503-163837
git checkout d383145190e87f46bc73d86059724df2b3af9720
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash fs/btrfs/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> fs/btrfs/ioctl.c:4350: warning: expecting prototype for Try to acquire fs_info:(). Prototype was for btrfs_try_lock_balance() instead
vim +4350 fs/btrfs/ioctl.c
4336
4337 /**
4338 * Try to acquire fs_info::balance_Mutex as well as set BTRFS_EXLCOP_BALANCE as
4339 * required.
4340 *
4341 * @fs_info: context of the filesystem
4342 * @excl_acquired: ptr to boolean value which is set to 'false' in case balance
4343 * is being resumed.
4344 *
4345 * Returns 0 on success in which case both fs_info::balance is acquired as well
4346 * as exclusive ops are blocked. In case of failure returns an error code.
4347 *
4348 */
4349 static int btrfs_try_lock_balance(struct btrfs_fs_info *fs_info, bool *excl_acquired)
> 4350 {
4351 int ret;
4352 /*
4353 * mut. excl. ops lock is locked. Three possibilities:
4354 * (1) some other op is running
4355 * (2) balance is running
4356 * (3) balance is paused -- special case (think resume)
4357 */
4358 while (1) {
4359 if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
4360 *excl_acquired = true;
4361 mutex_lock(&fs_info->balance_mutex);
4362 return 0;
4363 }
4364
4365 mutex_lock(&fs_info->balance_mutex);
4366 if (fs_info->balance_ctl) {
4367 /* this is either (2) or (3) */
4368 if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4369 /* this is (2) */
4370 ret = -EINPROGRESS;
4371 goto out_failure;
4372
4373 } else {
4374 mutex_unlock(&fs_info->balance_mutex);
4375 /*
4376 * Lock released to allow other waiters to continue,
4377 * we'll reexamine the status again.
4378 */
4379 mutex_lock(&fs_info->balance_mutex);
4380
4381 if (fs_info->balance_ctl &&
4382 !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4383 /* this is (3) */
4384 *excl_acquired = false;
4385 return 0;
4386 }
4387 }
4388 } else {
4389 /* this is (1) */
4390 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4391 goto out_failure;
4392 }
4393
4394 mutex_unlock(&fs_info->balance_mutex);
4395 }
4396
4397 out_failure:
4398 mutex_unlock(&fs_info->balance_mutex);
4399 *excl_acquired = false;
4400 return ret;
4401 }
4402
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 9d8e46815ee4..8e0cc17d5f81 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4334,6 +4334,72 @@ void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info, spin_unlock(&fs_info->balance_lock); } +/** + * Try to acquire fs_info::balance_Mutex as well as set BTRFS_EXLCOP_BALANCE as + * required. + * + * @fs_info: context of the filesystem + * @excl_acquired: ptr to boolean value which is set to 'false' in case balance + * is being resumed. + * + * Returns 0 on success in which case both fs_info::balance is acquired as well + * as exclusive ops are blocked. In case of failure returns an error code. + * + */ +static int btrfs_try_lock_balance(struct btrfs_fs_info *fs_info, bool *excl_acquired) +{ + int ret; + /* + * mut. excl. ops lock is locked. Three possibilities: + * (1) some other op is running + * (2) balance is running + * (3) balance is paused -- special case (think resume) + */ + while (1) { + if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { + *excl_acquired = true; + mutex_lock(&fs_info->balance_mutex); + return 0; + } + + mutex_lock(&fs_info->balance_mutex); + if (fs_info->balance_ctl) { + /* this is either (2) or (3) */ + if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { + /* this is (2) */ + ret = -EINPROGRESS; + goto out_failure; + + } else { + mutex_unlock(&fs_info->balance_mutex); + /* + * Lock released to allow other waiters to continue, + * we'll reexamine the status again. + */ + mutex_lock(&fs_info->balance_mutex); + + if (fs_info->balance_ctl && + !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { + /* this is (3) */ + *excl_acquired = false; + return 0; + } + } + } else { + /* this is (1) */ + ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; + goto out_failure; + } + + mutex_unlock(&fs_info->balance_mutex); + } + +out_failure: + mutex_unlock(&fs_info->balance_mutex); + *excl_acquired = false; + return ret; +} + static long btrfs_ioctl_balance(struct file *file, void __user *arg) { struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
This function contains the factored out locking sequence btrfs_ioctl_balance. Having this piece of code separate helps to simplify btrfs_ioctl_balance which has turned into a boiling pile of spaghetti. This will be used in the next patch to streamline the logic in btrfs_ioctl_balance. Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- fs/btrfs/ioctl.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+)