>On 2025/6/12 20:34, wangzijie wrote: >>> On 6/12/25 11:27, wangzijie wrote: >>>> Wu Bo once mentioned a fallocate fail scenario in this link[1]. >>>> After commit 3fdd89b452c2("f2fs: prevent writing without fallocate() >>>> for pinned files"), we cannot directly generate 4K size file and >>>> pin it, but we can still generate non-segment aligned pinned file: >>>> >>>> touch test_file >>>> ./f2fs_io pinfile set test_file >>>> ./f2fs_io fallocate 0 0 8192 test_file >>>> truncate -s 4096 test_file >>> >>> Well, shouldn't we avoid such case by adding check condition in setattr? >> >> Maybe like this? >> >> --- >> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >> index 6bd3de64f..2f6537d9c 100644 >> --- a/fs/f2fs/file.c >> +++ b/fs/f2fs/file.c >> @@ -1027,6 +1027,8 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct >> dentry *dentry, >> struct inode *inode = d_inode(dentry); >> struct f2fs_inode_info *fi = F2FS_I(inode); >> int err; >> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >> + block_t sec_blks = CAP_BLKS_PER_SEC(sbi); >> >> if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) >> return -EIO; >> @@ -1047,6 +1049,11 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct >> dentry *dentry, >> !IS_ALIGNED(attr->ia_size, >> F2FS_BLK_TO_BYTES(fi->i_cluster_size))) >> return -EINVAL; >> + if (f2fs_is_pinned_file(inode) && >> + attr->ia_size < i_size_read(inode) && >> + !IS_ALIGNED(attr->ia_size, >> + F2FS_BLK_TO_BYTES(sec_blks))); >> + return -EINVAL; >> } > >I think so, can you please send a formal patch?
OK, I will send a formal patch later. >> >> err = setattr_prepare(idmap, dentry, attr); >> --- >> >>>> >>>> By doing this, pin+fallocate failure(gc happens EAGAIN but f2fs shows >>>> enough spare space) may occurs. >>>> >>>> From message in commit 2e42b7f817ac("f2fs: stop allocating pinned sections >>>> if EAGAIN happens"), gc EAGAIN doesn't guarantee a free section, so we stop >>>> allocating. But after commit 48ea8b200414 ("f2fs: fix to avoid panic once >>>> fallocation fails for pinfile"), we have a way to avoid panic caused by >>>> concurrent pinfile allocation run out of free section, so I think that we >>>> can continue to allocate pinned section when gc happens EAGAIN. Even if we >>>> don't have free section, f2fs_allocate_pinning_section() can fail with >>>> ENOSPC. >>> >>> What do you think of introduce /sys/fs/f2fs/<dev>/reserved_pin_section to >>> tune @needed parameter of has_not_enough_free_secs()? If we configure it >>> w/ zero, it can avoid f2fs_gc() before preallocation. >>> >>> --- >>> fs/f2fs/f2fs.h | 3 +++ >>> fs/f2fs/file.c | 5 ++--- >>> fs/f2fs/super.c | 3 +++ >>> fs/f2fs/sysfs.c | 9 +++++++++ >>> 4 files changed, 17 insertions(+), 3 deletions(-) >>> >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>> index 785537576aa8..ffb15da570d7 100644 >>> --- a/fs/f2fs/f2fs.h >>> +++ b/fs/f2fs/f2fs.h >>> @@ -1731,6 +1731,9 @@ struct f2fs_sb_info { >>> /* for skip statistic */ >>> unsigned long long skipped_gc_rwsem; /* FG_GC only */ >>> >>> + /* free sections reserved for pinned file */ >>> + unsigned int reserved_pin_section; >>> + >>> /* threshold for gc trials on pinned files */ >>> unsigned short gc_pin_file_threshold; >>> struct f2fs_rwsem pin_sem; >>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>> index 696131e655ed..a909f79db178 100644 >>> --- a/fs/f2fs/file.c >>> +++ b/fs/f2fs/file.c >>> @@ -1887,9 +1887,8 @@ static int f2fs_expand_inode_data(struct inode >>> *inode, loff_t offset, >>> } >>> } >>> >>> - if (has_not_enough_free_secs(sbi, 0, f2fs_sb_has_blkzoned(sbi) ? >>> - ZONED_PIN_SEC_REQUIRED_COUNT : >>> - GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) { >>> + if (has_not_enough_free_secs(sbi, 0, >>> + sbi->reserved_pin_section)) { >>> f2fs_down_write(&sbi->gc_lock); >>> stat_inc_gc_call_count(sbi, FOREGROUND); >>> err = f2fs_gc(sbi, &gc_control); >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c >>> index 57adeff5ef25..48b97a95fd63 100644 >>> --- a/fs/f2fs/super.c >>> +++ b/fs/f2fs/super.c >>> @@ -4975,6 +4975,9 @@ static int f2fs_fill_super(struct super_block *sb, >>> struct fs_context *fc) >>> sbi->last_valid_block_count = sbi->total_valid_block_count; >>> sbi->reserved_blocks = 0; >>> sbi->current_reserved_blocks = 0; >>> + sbi->reserved_pin_section = f2fs_sb_has_blkzoned(sbi) ? >>> + ZONED_PIN_SEC_REQUIRED_COUNT : >>> + GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)); >>> limit_reserve_root(sbi); >>> adjust_unusable_cap_perc(sbi); >>> >>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c >>> index 75134d69a0bd..51be7ffb38c5 100644 >>> --- a/fs/f2fs/sysfs.c >>> +++ b/fs/f2fs/sysfs.c >>> @@ -824,6 +824,13 @@ static ssize_t __sbi_store(struct f2fs_attr *a, >>> return count; >>> } >>> >>> + if (!strcmp(a->attr.name, "reserved_pin_section")) { >>> + if (t > GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi))) >>> + return -EINVAL; >>> + *ui = (unsigned int)t; >>> + return count; >>> + } >>> + >>> *ui = (unsigned int)t; >>> >>> return count; >>> @@ -1130,6 +1137,7 @@ F2FS_SBI_GENERAL_RO_ATTR(unusable_blocks_per_sec); >>> F2FS_SBI_GENERAL_RW_ATTR(blkzone_alloc_policy); >>> #endif >>> F2FS_SBI_GENERAL_RW_ATTR(carve_out); >>> +F2FS_SBI_GENERAL_RW_ATTR(reserved_pin_section); >>> >>> /* STAT_INFO ATTR */ >>> #ifdef CONFIG_F2FS_STAT_FS >>> @@ -1323,6 +1331,7 @@ static struct attribute *f2fs_attrs[] = { >>> ATTR_LIST(last_age_weight), >>> ATTR_LIST(max_read_extent_count), >>> ATTR_LIST(carve_out), >>> + ATTR_LIST(reserved_pin_section), >>> NULL, >>> }; >>> ATTRIBUTE_GROUPS(f2fs); >>> -- >>> 2.49.0 >> >> I think it's a good way to solve this problem. Thank you! > >Sent a formal patch w/ below link. :) > >https://lore.kernel.org/linux-f2fs-devel/20250612140526.6435-1-c...@kernel.org > >Thanks, Thanks, I'll take a look at it. >> >> >>>> >>>> [1] >>>> https://lore.kernel.org/linux-f2fs-devel/20231030094024.263707-1-bo...@vivo.com/t/#u >>>> >>>> Signed-off-by: wangzijie <wangzij...@honor.com> >>>> --- >>>> fs/f2fs/file.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>>> index 6bd3de64f..05c80d2b5 100644 >>>> --- a/fs/f2fs/file.c >>>> +++ b/fs/f2fs/file.c >>>> @@ -1859,7 +1859,7 @@ static int f2fs_expand_inode_data(struct inode >>>> *inode, loff_t offset, >>>> f2fs_down_write(&sbi->gc_lock); >>>> stat_inc_gc_call_count(sbi, FOREGROUND); >>>> err = f2fs_gc(sbi, &gc_control); >>>> - if (err && err != -ENODATA) { >>>> + if (err && err != -ENODATA && err != -EAGAIN) { >>>> f2fs_up_write(&sbi->pin_sem); >>>> goto out_err; >>>> } >>> >>> >>> >>> _______________________________________________ >>> Linux-f2fs-devel mailing list >>> Linux-f2fs-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >> > > > >_______________________________________________ >Linux-f2fs-devel mailing list >Linux-f2fs-devel@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel