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* Re: [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range()
       [not found] <202107251600.qcLierqr-lkp@intel.com>
@ 2021-07-26  3:42 ` kernel test robot
  0 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2021-07-26  3:42 UTC (permalink / raw)
  To: Wang Jianchao, linux-ext4, LKML; +Cc: kbuild-all, tytso, adilger.kernel

[-- Attachment #1: Type: text/plain, Size: 17042 bytes --]

Hi Wang,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on ext4/dev]
[also build test WARNING on linux/master linus/master v5.14-rc2 
next-20210723]
[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/0day-ci/linux/commits/Wang-Jianchao/ext4-get-discard-out-of-jbd2-commit-context/20210724-154426
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
:::::: branch date: 25 hours ago
:::::: commit date: 25 hours ago
config: x86_64-randconfig-c001-20210725 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 
c63dbd850182797bc4b76124d08e1c320ab2365d)
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
         # install x86_64 cross compiling tool for clang build
         # apt-get install binutils-x86-64-linux-gnu
         # 
https://github.com/0day-ci/linux/commit/55a3430685e83709742c1fe2e0d4b347781bcc80
         git remote add linux-review https://github.com/0day-ci/linux
         git fetch --no-tags linux-review 
Wang-Jianchao/ext4-get-discard-out-of-jbd2-commit-context/20210724-154426
         git checkout 55a3430685e83709742c1fe2e0d4b347781bcc80
         # save the attached .config to linux build tree
         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross 
clang-analyzer ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


clang-analyzer warnings: (new ones prefixed by >>)
    fs/ext4/mballoc.c:1909:2: note: Taking true branch
            if (ex->fe_start + ex->fe_len > 
EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
            ^
    fs/ext4/mballoc.c:1911:3: note: Taking true branch
                    WARN_ON(1);
                    ^
    include/asm-generic/bug.h:120:2: note: expanded from macro 'WARN_ON'
            if (unlikely(__ret_warn_on)) 
     \
            ^
    fs/ext4/mballoc.c:1911:3: note: Loop condition is false.  Exiting loop
                    WARN_ON(1);
                    ^
    include/asm-generic/bug.h:121:3: note: expanded from macro 'WARN_ON'
                    __WARN(); 
     \
                    ^
    include/asm-generic/bug.h:94:19: note: expanded from macro '__WARN'
    #define __WARN()                __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                                    ^
    arch/x86/include/asm/bug.h:78:2: note: expanded from macro 
'__WARN_FLAGS'
            instrumentation_begin();                                \
            ^
    include/linux/instrumentation.h:53:34: note: expanded from macro 
'instrumentation_begin'
    # define instrumentation_begin()        do { } while(0)
                                            ^
    fs/ext4/mballoc.c:1911:3: note: Loop condition is false.  Exiting loop
                    WARN_ON(1);
                    ^
    include/asm-generic/bug.h:121:3: note: expanded from macro 'WARN_ON'
                    __WARN(); 
     \
                    ^
    include/asm-generic/bug.h:94:19: note: expanded from macro '__WARN'
    #define __WARN()                __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                                    ^
    arch/x86/include/asm/bug.h:79:2: note: expanded from macro 
'__WARN_FLAGS'
            _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags));           \
            ^
    arch/x86/include/asm/bug.h:25:37: note: expanded from macro '_BUG_FLAGS'
    #define _BUG_FLAGS(ins, flags) 
     \
 
     ^
    fs/ext4/mballoc.c:1911:3: note: Loop condition is false.  Exiting loop
                    WARN_ON(1);
                    ^
    include/asm-generic/bug.h:121:3: note: expanded from macro 'WARN_ON'
                    __WARN(); 
     \
                    ^
    include/asm-generic/bug.h:94:19: note: expanded from macro '__WARN'
    #define __WARN()                __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                                    ^
    arch/x86/include/asm/bug.h:81:2: note: expanded from macro 
'__WARN_FLAGS'
            instrumentation_end();                                  \
            ^
    include/linux/instrumentation.h:54:33: note: expanded from macro 
'instrumentation_end'
    # define instrumentation_end()          do { } while(0)
                                            ^
    fs/ext4/mballoc.c:1911:3: note: Loop condition is false.  Exiting loop
                    WARN_ON(1);
                    ^
    include/asm-generic/bug.h:121:3: note: expanded from macro 'WARN_ON'
                    __WARN(); 
     \
                    ^
    include/asm-generic/bug.h:94:19: note: expanded from macro '__WARN'
    #define __WARN()                __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                                    ^
    arch/x86/include/asm/bug.h:76:33: note: expanded from macro 
'__WARN_FLAGS'
    #define __WARN_FLAGS(flags)                                     \
                                                                    ^
    fs/ext4/mballoc.c:1912:3: note: 14th function call argument is an 
uninitialized value
                    ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
                    ^
    fs/ext4/ext4.h:3126:2: note: expanded from macro 'ext4_grp_locked_error'
            __ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, 
block, \
            ^
    fs/ext4/mballoc.c:2597:27: warning: Value stored to 'grp' during its 
initialization is never read [clang-analyzer-deadcode.DeadStores]
                    struct ext4_group_info *grp = 
ext4_get_group_info(sb, group);
                                            ^~~ 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    fs/ext4/mballoc.c:2597:27: note: Value stored to 'grp' during its 
initialization is never read
                    struct ext4_group_info *grp = 
ext4_get_group_info(sb, group);
                                            ^~~ 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    fs/ext4/mballoc.c:3839:3: warning: Value stored to 'err' is never 
read [clang-analyzer-deadcode.DeadStores]
                    err = PTR_ERR(bitmap_bh);
                    ^     ~~~~~~~~~~~~~~~~~~
    fs/ext4/mballoc.c:3839:3: note: Value stored to 'err' is never read
                    err = PTR_ERR(bitmap_bh);
                    ^     ~~~~~~~~~~~~~~~~~~
    fs/ext4/mballoc.c:3844:2: warning: Value stored to 'err' is never 
read [clang-analyzer-deadcode.DeadStores]
            err = -EIO;
            ^     ~~~~
    fs/ext4/mballoc.c:3844:2: note: Value stored to 'err' is never read
            err = -EIO;
            ^     ~~~~
    fs/ext4/mballoc.c:3889:2: warning: Value stored to 'err' is never 
read [clang-analyzer-deadcode.DeadStores]
            err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
            ^
    fs/ext4/mballoc.c:3889:2: note: Value stored to 'err' is never read
    fs/ext4/mballoc.c:5746:3: warning: Value stored to 'err' is never 
read [clang-analyzer-deadcode.DeadStores]
                    err = PTR_ERR(bitmap_bh);
                    ^     ~~~~~~~~~~~~~~~~~~
    fs/ext4/mballoc.c:5746:3: note: Value stored to 'err' is never read
                    err = PTR_ERR(bitmap_bh);
                    ^     ~~~~~~~~~~~~~~~~~~
>> fs/ext4/mballoc.c:6245:4: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
                            ret = 0;
                            ^     ~
    fs/ext4/mballoc.c:6245:4: note: Value stored to 'ret' is never read
                            ret = 0;
                            ^     ~
    Suppressed 6 warnings (6 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    4 warnings generated.
    Suppressed 4 warnings (4 in non-user code).
    Use -header-filter=.* to display errors from all non-system headers. 
Use -system-headers to display errors from system headers as well.
    12 warnings generated.
    arch/x86/include/asm/paravirt.h:585:2: warning: Assigned value is 
garbage or undefined [clang-analyzer-core.uninitialized.Assign]
            PVOP_VCALL2(lock.queued_spin_lock_slowpath, lock, val);
            ^
    arch/x86/include/asm/paravirt_types.h:547:2: note: expanded from 
macro 'PVOP_VCALL2'
            __PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))
            ^
    arch/x86/include/asm/paravirt_types.h:491:8: note: expanded from 
macro '__PVOP_VCALL'
            (void)____PVOP_CALL(, op, CLBR_ANY, PVOP_VCALL_CLOBBERS, 
     \
                  ^
    arch/x86/include/asm/paravirt_types.h:446:3: note: expanded from 
macro '____PVOP_CALL'
                    PVOP_CALL_ARGS; 
     \
                    ^
    arch/x86/include/asm/paravirt_types.h:404:16: note: expanded from 
macro 'PVOP_CALL_ARGS'
            unsigned long __edi = __edi, __esi = __esi,             \
                          ^
    kernel/trace/trace.c:5779:2: note: Calling 'queued_spin_lock'
            arch_spin_lock(&trace_cmdline_lock);
            ^
    include/asm-generic/qspinlock.h:117:28: note: expanded from macro 
'arch_spin_lock'
    #define arch_spin_lock(l)               queued_spin_lock(l)
                                            ^~~~~~~~~~~~~~~~~~~
    include/asm-generic/qspinlock.h:82:6: note: Assuming the condition 
is false
            if (likely(atomic_try_cmpxchg_acquire(&lock->val, &val, 
_Q_LOCKED_VAL)))
                ^
    include/linux/compiler.h:77:20: note: expanded from macro 'likely'
    # define likely(x)      __builtin_expect(!!(x), 1)
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~
    include/asm-generic/qspinlock.h:82:2: note: Taking false branch
            if (likely(atomic_try_cmpxchg_acquire(&lock->val, &val, 
_Q_LOCKED_VAL)))
            ^
    include/asm-generic/qspinlock.h:85:2: note: Calling 
'queued_spin_lock_slowpath'
            queued_spin_lock_slowpath(lock, val);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/x86/include/asm/qspinlock.h:51:2: note: Calling 
'pv_queued_spin_lock_slowpath'
            pv_queued_spin_lock_slowpath(lock, val);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/x86/include/asm/paravirt.h:585:2: note: Assigned value is 
garbage or undefined
            PVOP_VCALL2(lock.queued_spin_lock_slowpath, lock, val);
            ^
    arch/x86/include/asm/paravirt_types.h:547:2: note: expanded from 
macro 'PVOP_VCALL2'
            __PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/x86/include/asm/paravirt_types.h:491:8: note: expanded from 
macro '__PVOP_VCALL'
            (void)____PVOP_CALL(, op, CLBR_ANY, PVOP_VCALL_CLOBBERS, 
     \
 
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/x86/include/asm/paravirt_types.h:446:3: note: expanded from 
macro '____PVOP_CALL'
                    PVOP_CALL_ARGS; 
     \
                    ^~~~~~~~~~~~~~
    arch/x86/include/asm/paravirt_types.h:404:16: note: expanded from 
macro 'PVOP_CALL_ARGS'
            unsigned long __edi = __edi, __esi = __esi,             \
                          ^       ~~~~~
    arch/x86/include/asm/paravirt.h:590:2: warning: Assigned value is 
garbage or undefined [clang-analyzer-core.uninitialized.Assign]
            PVOP_ALT_VCALLEE1(lock.queued_spin_unlock, lock,
            ^
    arch/x86/include/asm/paravirt_types.h:541:2: note: expanded from 
macro 'PVOP_ALT_VCALLEE1'
            __PVOP_ALT_VCALLEESAVE(op, alt, cond, PVOP_CALL_ARG1(arg1))
            ^
    arch/x86/include/asm/paravirt_types.h:504:8: note: expanded from 
macro '__PVOP_ALT_VCALLEESAVE'
            (void)____PVOP_ALT_CALL(, op.func, alt, cond, CLBR_RET_REG, 
     \
                  ^
    arch/x86/include/asm/paravirt_types.h:460:3: note: expanded from 
macro '____PVOP_ALT_CALL'
                    PVOP_CALL_ARGS; 
     \
                    ^
    arch/x86/include/asm/paravirt_types.h:404:16: note: expanded from 
macro 'PVOP_CALL_ARGS'
            unsigned long __edi = __edi, __esi = __esi,             \
                          ^
    kernel/trace/trace.c:9948:6: note: Assuming 'tracepoint_printk' is 0
            if (tracepoint_printk) {
                ^~~~~~~~~~~~~~~~~
    kernel/trace/trace.c:9948:2: note: Taking false branch
            if (tracepoint_printk) {
            ^
    kernel/trace/trace.c:9957:2: note: Calling 'tracer_alloc_buffers'
            tracer_alloc_buffers();
            ^~~~~~~~~~~~~~~~~~~~~~
    kernel/trace/trace.c:9821:6: note: Assuming the condition is false
            if (security_locked_down(LOCKDOWN_TRACEFS)) {
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    kernel/trace/trace.c:9821:2: note: Taking false branch
            if (security_locked_down(LOCKDOWN_TRACEFS)) {
            ^
    kernel/trace/trace.c:9830:15: note: TRACE_ITER_LAST_BIT is <= 32
            BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);
                         ^
    include/linux/build_bug.h:50:19: note: expanded from macro 
'BUILD_BUG_ON'
            BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
                             ^~~~~~~~~
    include/linux/build_bug.h:39:58: note: expanded from macro 
'BUILD_BUG_ON_MSG'
    #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)

vim +/ret +6245 fs/ext4/mballoc.c

7360d1731e5dc7 Lukas Czerner 2010-10-27  6220  55a3430685e837 Wang 
Jianchao 2021-07-24  6221  static int ext4_try_to_trim_range(struct 
super_block *sb,
55a3430685e837 Wang Jianchao 2021-07-24  6222  		struct ext4_buddy *e4b, 
ext4_grpblk_t start,
55a3430685e837 Wang Jianchao 2021-07-24  6223  		ext4_grpblk_t max, 
ext4_grpblk_t minblocks)
55a3430685e837 Wang Jianchao 2021-07-24  6224  {
55a3430685e837 Wang Jianchao 2021-07-24  6225  	ext4_grpblk_t next, 
count, free_count;
55a3430685e837 Wang Jianchao 2021-07-24  6226  	void *bitmap;
55a3430685e837 Wang Jianchao 2021-07-24  6227  	int ret = 0;
55a3430685e837 Wang Jianchao 2021-07-24  6228  55a3430685e837 Wang 
Jianchao 2021-07-24  6229  	bitmap = e4b->bd_bitmap;
55a3430685e837 Wang Jianchao 2021-07-24  6230  	start = 
(e4b->bd_info->bb_first_free > start) ?
55a3430685e837 Wang Jianchao 2021-07-24  6231  	 
e4b->bd_info->bb_first_free : start;
55a3430685e837 Wang Jianchao 2021-07-24  6232  	count = 0;
55a3430685e837 Wang Jianchao 2021-07-24  6233  	free_count = 0;
55a3430685e837 Wang Jianchao 2021-07-24  6234  55a3430685e837 Wang 
Jianchao 2021-07-24  6235  	while (start <= max) {
55a3430685e837 Wang Jianchao 2021-07-24  6236  		start = 
mb_find_next_zero_bit(bitmap, max + 1, start);
55a3430685e837 Wang Jianchao 2021-07-24  6237  		if (start > max)
55a3430685e837 Wang Jianchao 2021-07-24  6238  			break;
55a3430685e837 Wang Jianchao 2021-07-24  6239  		next = 
mb_find_next_bit(bitmap, max + 1, start);
55a3430685e837 Wang Jianchao 2021-07-24  6240  55a3430685e837 Wang 
Jianchao 2021-07-24  6241  		if ((next - start) >= minblocks) {
55a3430685e837 Wang Jianchao 2021-07-24  6242  			ret = 
ext4_trim_extent(sb, start, next - start, e4b);
55a3430685e837 Wang Jianchao 2021-07-24  6243  			if (ret && ret != 
-EOPNOTSUPP)
55a3430685e837 Wang Jianchao 2021-07-24  6244  				break;
55a3430685e837 Wang Jianchao 2021-07-24 @6245  			ret = 0;
55a3430685e837 Wang Jianchao 2021-07-24  6246  			count += next - start;
55a3430685e837 Wang Jianchao 2021-07-24  6247  		}
55a3430685e837 Wang Jianchao 2021-07-24  6248  		free_count += next - start;
55a3430685e837 Wang Jianchao 2021-07-24  6249  		start = next + 1;
55a3430685e837 Wang Jianchao 2021-07-24  6250  55a3430685e837 Wang 
Jianchao 2021-07-24  6251  		if (fatal_signal_pending(current)) {
55a3430685e837 Wang Jianchao 2021-07-24  6252  			count = -ERESTARTSYS;
55a3430685e837 Wang Jianchao 2021-07-24  6253  			break;
55a3430685e837 Wang Jianchao 2021-07-24  6254  		}
55a3430685e837 Wang Jianchao 2021-07-24  6255  55a3430685e837 Wang 
Jianchao 2021-07-24  6256  		if (need_resched()) {
55a3430685e837 Wang Jianchao 2021-07-24  6257  			ext4_unlock_group(sb, 
e4b->bd_group);
55a3430685e837 Wang Jianchao 2021-07-24  6258  			cond_resched();
55a3430685e837 Wang Jianchao 2021-07-24  6259  			ext4_lock_group(sb, 
e4b->bd_group);
55a3430685e837 Wang Jianchao 2021-07-24  6260  		}
55a3430685e837 Wang Jianchao 2021-07-24  6261  55a3430685e837 Wang 
Jianchao 2021-07-24  6262  		if ((e4b->bd_info->bb_free - free_count) < 
minblocks)
55a3430685e837 Wang Jianchao 2021-07-24  6263  			break;
55a3430685e837 Wang Jianchao 2021-07-24  6264  	}
55a3430685e837 Wang Jianchao 2021-07-24  6265  55a3430685e837 Wang 
Jianchao 2021-07-24  6266  	return count;
55a3430685e837 Wang Jianchao 2021-07-24  6267  }
55a3430685e837 Wang Jianchao 2021-07-24  6268
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org


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_______________________________________________
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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range()
  2021-08-12 17:44   ` Theodore Ts'o
@ 2021-08-26  7:19     ` Wang Jianchao
  0 siblings, 0 replies; 5+ messages in thread
From: Wang Jianchao @ 2021-08-26  7:19 UTC (permalink / raw)
  To: Theodore Ts'o; +Cc: linux-ext4, linux-kernel, adilger.kernel



On 2021/8/13 1:44 AM, Theodore Ts'o wrote:
> On Sat, Jul 24, 2021 at 03:41:21PM +0800, Wang Jianchao wrote:
>> From: Wang Jianchao <wangjianchao@kuaishou.com>
>>
>> There is no functional change in this patch but just split the
>> codes, which serachs free block and does trim, into a new function
>> ext4_try_to_trim_range. This is preparing for the following async
>> backgroup discard.
>>
>> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
>> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com>
>> ---
>>  fs/ext4/mballoc.c | 102 ++++++++++++++++++++++++++--------------------
>>  1 file changed, 57 insertions(+), 45 deletions(-)
>>
>> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
>> index 018d5d3c6eeb..e3844152a643 100644
>> --- a/fs/ext4/mballoc.c
>> +++ b/fs/ext4/mballoc.c
>> @@ -6218,6 +6218,54 @@ __acquires(bitlock)
>>  	return ret;
>>  }
>>  
>> +static int ext4_try_to_trim_range(struct super_block *sb,
>> +		struct ext4_buddy *e4b, ext4_grpblk_t start,
>> +		ext4_grpblk_t max, ext4_grpblk_t minblocks)
>> +{
>> +	ext4_grpblk_t next, count, free_count;
>> +	void *bitmap;
>> +	int ret = 0;
>> +
>> +	bitmap = e4b->bd_bitmap;
>> +	start = (e4b->bd_info->bb_first_free > start) ?
>> +		e4b->bd_info->bb_first_free : start;
>> +	count = 0;
>> +	free_count = 0;
>> +
>> +	while (start <= max) {
>> +		start = mb_find_next_zero_bit(bitmap, max + 1, start);
>> +		if (start > max)
>> +			break;
>> +		next = mb_find_next_bit(bitmap, max + 1, start);
>> +
>> +		if ((next - start) >= minblocks) {
>> +			ret = ext4_trim_extent(sb, start, next - start, e4b);
>> +			if (ret && ret != -EOPNOTSUPP)
>> +				break;
>> +			ret = 0;
>> +			count += next - start;
>> +		}
> 
> "ret" is only used inside the if statement, so this might be better as:
> 
>> +		if ((next - start) >= minblocks) {
>> +			int ret = ext4_trim_extent(sb, start, next - start, e4b);
>> +
>> +			if (ret && ret != -EOPNOTSUPP)
>> +				break;
>> +			count += next - start;
>> +		}
> 
> ... and then drop the "int ret = 0" above.
> 
> Otherwise, looks good.
> 

OK, I'll do it in next version

Thanks so much
Jianchao
> 						- Ted
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range()
  2021-07-24  7:41 ` [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range() Wang Jianchao
  2021-08-04 15:29   ` Jan Kara
@ 2021-08-12 17:44   ` Theodore Ts'o
  2021-08-26  7:19     ` Wang Jianchao
  1 sibling, 1 reply; 5+ messages in thread
From: Theodore Ts'o @ 2021-08-12 17:44 UTC (permalink / raw)
  To: Wang Jianchao; +Cc: linux-ext4, linux-kernel, adilger.kernel

On Sat, Jul 24, 2021 at 03:41:21PM +0800, Wang Jianchao wrote:
> From: Wang Jianchao <wangjianchao@kuaishou.com>
> 
> There is no functional change in this patch but just split the
> codes, which serachs free block and does trim, into a new function
> ext4_try_to_trim_range. This is preparing for the following async
> backgroup discard.
> 
> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com>
> ---
>  fs/ext4/mballoc.c | 102 ++++++++++++++++++++++++++--------------------
>  1 file changed, 57 insertions(+), 45 deletions(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 018d5d3c6eeb..e3844152a643 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -6218,6 +6218,54 @@ __acquires(bitlock)
>  	return ret;
>  }
>  
> +static int ext4_try_to_trim_range(struct super_block *sb,
> +		struct ext4_buddy *e4b, ext4_grpblk_t start,
> +		ext4_grpblk_t max, ext4_grpblk_t minblocks)
> +{
> +	ext4_grpblk_t next, count, free_count;
> +	void *bitmap;
> +	int ret = 0;
> +
> +	bitmap = e4b->bd_bitmap;
> +	start = (e4b->bd_info->bb_first_free > start) ?
> +		e4b->bd_info->bb_first_free : start;
> +	count = 0;
> +	free_count = 0;
> +
> +	while (start <= max) {
> +		start = mb_find_next_zero_bit(bitmap, max + 1, start);
> +		if (start > max)
> +			break;
> +		next = mb_find_next_bit(bitmap, max + 1, start);
> +
> +		if ((next - start) >= minblocks) {
> +			ret = ext4_trim_extent(sb, start, next - start, e4b);
> +			if (ret && ret != -EOPNOTSUPP)
> +				break;
> +			ret = 0;
> +			count += next - start;
> +		}

"ret" is only used inside the if statement, so this might be better as:

> +		if ((next - start) >= minblocks) {
> +			int ret = ext4_trim_extent(sb, start, next - start, e4b);
> +
> +			if (ret && ret != -EOPNOTSUPP)
> +				break;
> +			count += next - start;
> +		}

... and then drop the "int ret = 0" above.

Otherwise, looks good.

						- Ted

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range()
  2021-07-24  7:41 ` [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range() Wang Jianchao
@ 2021-08-04 15:29   ` Jan Kara
  2021-08-12 17:44   ` Theodore Ts'o
  1 sibling, 0 replies; 5+ messages in thread
From: Jan Kara @ 2021-08-04 15:29 UTC (permalink / raw)
  To: Wang Jianchao; +Cc: linux-ext4, linux-kernel, tytso, adilger.kernel

On Sat 24-07-21 15:41:21, Wang Jianchao wrote:
> From: Wang Jianchao <wangjianchao@kuaishou.com>
> 
> There is no functional change in this patch but just split the
> codes, which serachs free block and does trim, into a new function
> ext4_try_to_trim_range. This is preparing for the following async
> backgroup discard.
> 
> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/mballoc.c | 102 ++++++++++++++++++++++++++--------------------
>  1 file changed, 57 insertions(+), 45 deletions(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 018d5d3c6eeb..e3844152a643 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -6218,6 +6218,54 @@ __acquires(bitlock)
>  	return ret;
>  }
>  
> +static int ext4_try_to_trim_range(struct super_block *sb,
> +		struct ext4_buddy *e4b, ext4_grpblk_t start,
> +		ext4_grpblk_t max, ext4_grpblk_t minblocks)
> +{
> +	ext4_grpblk_t next, count, free_count;
> +	void *bitmap;
> +	int ret = 0;
> +
> +	bitmap = e4b->bd_bitmap;
> +	start = (e4b->bd_info->bb_first_free > start) ?
> +		e4b->bd_info->bb_first_free : start;
> +	count = 0;
> +	free_count = 0;
> +
> +	while (start <= max) {
> +		start = mb_find_next_zero_bit(bitmap, max + 1, start);
> +		if (start > max)
> +			break;
> +		next = mb_find_next_bit(bitmap, max + 1, start);
> +
> +		if ((next - start) >= minblocks) {
> +			ret = ext4_trim_extent(sb, start, next - start, e4b);
> +			if (ret && ret != -EOPNOTSUPP)
> +				break;
> +			ret = 0;
> +			count += next - start;
> +		}
> +		free_count += next - start;
> +		start = next + 1;
> +
> +		if (fatal_signal_pending(current)) {
> +			count = -ERESTARTSYS;
> +			break;
> +		}
> +
> +		if (need_resched()) {
> +			ext4_unlock_group(sb, e4b->bd_group);
> +			cond_resched();
> +			ext4_lock_group(sb, e4b->bd_group);
> +		}
> +
> +		if ((e4b->bd_info->bb_free - free_count) < minblocks)
> +			break;
> +	}
> +
> +	return count;
> +}
> +
>  /**
>   * ext4_trim_all_free -- function to trim all free space in alloc. group
>   * @sb:			super block for file system
> @@ -6241,10 +6289,8 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
>  		   ext4_grpblk_t start, ext4_grpblk_t max,
>  		   ext4_grpblk_t minblocks)
>  {
> -	void *bitmap;
> -	ext4_grpblk_t next, count = 0, free_count = 0;
>  	struct ext4_buddy e4b;
> -	int ret = 0;
> +	int ret;
>  
>  	trace_ext4_trim_all_free(sb, group, start, max);
>  
> @@ -6254,57 +6300,23 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
>  			     ret, group);
>  		return ret;
>  	}
> -	bitmap = e4b.bd_bitmap;
>  
>  	ext4_lock_group(sb, group);
> -	if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
> -	    minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
> -		goto out;
> -
> -	start = (e4b.bd_info->bb_first_free > start) ?
> -		e4b.bd_info->bb_first_free : start;
>  
> -	while (start <= max) {
> -		start = mb_find_next_zero_bit(bitmap, max + 1, start);
> -		if (start > max)
> -			break;
> -		next = mb_find_next_bit(bitmap, max + 1, start);
> -
> -		if ((next - start) >= minblocks) {
> -			ret = ext4_trim_extent(sb, start, next - start, &e4b);
> -			if (ret && ret != -EOPNOTSUPP)
> -				break;
> -			ret = 0;
> -			count += next - start;
> -		}
> -		free_count += next - start;
> -		start = next + 1;
> -
> -		if (fatal_signal_pending(current)) {
> -			count = -ERESTARTSYS;
> -			break;
> -		}
> -
> -		if (need_resched()) {
> -			ext4_unlock_group(sb, group);
> -			cond_resched();
> -			ext4_lock_group(sb, group);
> -		}
> -
> -		if ((e4b.bd_info->bb_free - free_count) < minblocks)
> -			break;
> +	if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
> +	    minblocks < atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) {
> +		ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks);
> +		if (ret >= 0)
> +			EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
> +	} else {
> +		ret = 0;
>  	}
>  
> -	if (!ret) {
> -		ret = count;
> -		EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
> -	}
> -out:
>  	ext4_unlock_group(sb, group);
>  	ext4_mb_unload_buddy(&e4b);
>  
>  	ext4_debug("trimmed %d blocks in the group %d\n",
> -		count, group);
> +		ret, group);
>  
>  	return ret;
>  }
> -- 
> 2.17.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range()
  2021-07-24  7:41 [PATCH V3 0/5] ext4: get discard out of jbd2 commit context Wang Jianchao
@ 2021-07-24  7:41 ` Wang Jianchao
  2021-08-04 15:29   ` Jan Kara
  2021-08-12 17:44   ` Theodore Ts'o
  0 siblings, 2 replies; 5+ messages in thread
From: Wang Jianchao @ 2021-07-24  7:41 UTC (permalink / raw)
  To: linux-ext4, linux-kernel; +Cc: tytso, adilger.kernel

From: Wang Jianchao <wangjianchao@kuaishou.com>

There is no functional change in this patch but just split the
codes, which serachs free block and does trim, into a new function
ext4_try_to_trim_range. This is preparing for the following async
backgroup discard.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com>
---
 fs/ext4/mballoc.c | 102 ++++++++++++++++++++++++++--------------------
 1 file changed, 57 insertions(+), 45 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 018d5d3c6eeb..e3844152a643 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -6218,6 +6218,54 @@ __acquires(bitlock)
 	return ret;
 }
 
+static int ext4_try_to_trim_range(struct super_block *sb,
+		struct ext4_buddy *e4b, ext4_grpblk_t start,
+		ext4_grpblk_t max, ext4_grpblk_t minblocks)
+{
+	ext4_grpblk_t next, count, free_count;
+	void *bitmap;
+	int ret = 0;
+
+	bitmap = e4b->bd_bitmap;
+	start = (e4b->bd_info->bb_first_free > start) ?
+		e4b->bd_info->bb_first_free : start;
+	count = 0;
+	free_count = 0;
+
+	while (start <= max) {
+		start = mb_find_next_zero_bit(bitmap, max + 1, start);
+		if (start > max)
+			break;
+		next = mb_find_next_bit(bitmap, max + 1, start);
+
+		if ((next - start) >= minblocks) {
+			ret = ext4_trim_extent(sb, start, next - start, e4b);
+			if (ret && ret != -EOPNOTSUPP)
+				break;
+			ret = 0;
+			count += next - start;
+		}
+		free_count += next - start;
+		start = next + 1;
+
+		if (fatal_signal_pending(current)) {
+			count = -ERESTARTSYS;
+			break;
+		}
+
+		if (need_resched()) {
+			ext4_unlock_group(sb, e4b->bd_group);
+			cond_resched();
+			ext4_lock_group(sb, e4b->bd_group);
+		}
+
+		if ((e4b->bd_info->bb_free - free_count) < minblocks)
+			break;
+	}
+
+	return count;
+}
+
 /**
  * ext4_trim_all_free -- function to trim all free space in alloc. group
  * @sb:			super block for file system
@@ -6241,10 +6289,8 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
 		   ext4_grpblk_t start, ext4_grpblk_t max,
 		   ext4_grpblk_t minblocks)
 {
-	void *bitmap;
-	ext4_grpblk_t next, count = 0, free_count = 0;
 	struct ext4_buddy e4b;
-	int ret = 0;
+	int ret;
 
 	trace_ext4_trim_all_free(sb, group, start, max);
 
@@ -6254,57 +6300,23 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
 			     ret, group);
 		return ret;
 	}
-	bitmap = e4b.bd_bitmap;
 
 	ext4_lock_group(sb, group);
-	if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
-	    minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
-		goto out;
-
-	start = (e4b.bd_info->bb_first_free > start) ?
-		e4b.bd_info->bb_first_free : start;
 
-	while (start <= max) {
-		start = mb_find_next_zero_bit(bitmap, max + 1, start);
-		if (start > max)
-			break;
-		next = mb_find_next_bit(bitmap, max + 1, start);
-
-		if ((next - start) >= minblocks) {
-			ret = ext4_trim_extent(sb, start, next - start, &e4b);
-			if (ret && ret != -EOPNOTSUPP)
-				break;
-			ret = 0;
-			count += next - start;
-		}
-		free_count += next - start;
-		start = next + 1;
-
-		if (fatal_signal_pending(current)) {
-			count = -ERESTARTSYS;
-			break;
-		}
-
-		if (need_resched()) {
-			ext4_unlock_group(sb, group);
-			cond_resched();
-			ext4_lock_group(sb, group);
-		}
-
-		if ((e4b.bd_info->bb_free - free_count) < minblocks)
-			break;
+	if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
+	    minblocks < atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) {
+		ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks);
+		if (ret >= 0)
+			EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
+	} else {
+		ret = 0;
 	}
 
-	if (!ret) {
-		ret = count;
-		EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
-	}
-out:
 	ext4_unlock_group(sb, group);
 	ext4_mb_unload_buddy(&e4b);
 
 	ext4_debug("trimmed %d blocks in the group %d\n",
-		count, group);
+		ret, group);
 
 	return ret;
 }
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-08-26  7:19 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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2021-07-26  3:42 ` [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range() kernel test robot
2021-07-24  7:41 [PATCH V3 0/5] ext4: get discard out of jbd2 commit context Wang Jianchao
2021-07-24  7:41 ` [PATCH V3 2/5] ext4: add new helper interface ext4_try_to_trim_range() Wang Jianchao
2021-08-04 15:29   ` Jan Kara
2021-08-12 17:44   ` Theodore Ts'o
2021-08-26  7:19     ` Wang Jianchao

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