diff options
author | Chao Yu <chao@kernel.org> | 2021-12-11 21:27:36 +0800 |
---|---|---|
committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2022-01-04 13:20:56 -0800 |
commit | 300a842937fbcfb5a189cea9ba15374fdb0b5c6b (patch) | |
tree | b0edad128c983b69f1610fe44277d6880cf4e132 /fs/f2fs | |
parent | b702c83e2eaa2fa2d72e957c55c0321535cc8b9f (diff) | |
download | linux-300a842937fbcfb5a189cea9ba15374fdb0b5c6b.tar.bz2 |
f2fs: fix to reserve space for IO align feature
https://bugzilla.kernel.org/show_bug.cgi?id=204137
With below script, we will hit panic during new segment allocation:
DISK=bingo.img
MOUNT_DIR=/mnt/f2fs
dd if=/dev/zero of=$DISK bs=1M count=105
mkfs.f2fe -a 1 -o 19 -t 1 -z 1 -f -q $DISK
mount -t f2fs $DISK $MOUNT_DIR -o "noinline_dentry,flush_merge,noextent_cache,mode=lfs,io_bits=7,fsync_mode=strict"
for (( i = 0; i < 4096; i++ )); do
name=`head /dev/urandom | tr -dc A-Za-z0-9 | head -c 10`
mkdir $MOUNT_DIR/$name
done
umount $MOUNT_DIR
rm $DISK
--- Core dump ---
Call Trace:
allocate_segment_by_default+0x9d/0x100 [f2fs]
f2fs_allocate_data_block+0x3c0/0x5c0 [f2fs]
do_write_page+0x62/0x110 [f2fs]
f2fs_outplace_write_data+0x43/0xc0 [f2fs]
f2fs_do_write_data_page+0x386/0x560 [f2fs]
__write_data_page+0x706/0x850 [f2fs]
f2fs_write_cache_pages+0x267/0x6a0 [f2fs]
f2fs_write_data_pages+0x19c/0x2e0 [f2fs]
do_writepages+0x1c/0x70
__filemap_fdatawrite_range+0xaa/0xe0
filemap_fdatawrite+0x1f/0x30
f2fs_sync_dirty_inodes+0x74/0x1f0 [f2fs]
block_operations+0xdc/0x350 [f2fs]
f2fs_write_checkpoint+0x104/0x1150 [f2fs]
f2fs_sync_fs+0xa2/0x120 [f2fs]
f2fs_balance_fs_bg+0x33c/0x390 [f2fs]
f2fs_write_node_pages+0x4c/0x1f0 [f2fs]
do_writepages+0x1c/0x70
__writeback_single_inode+0x45/0x320
writeback_sb_inodes+0x273/0x5c0
wb_writeback+0xff/0x2e0
wb_workfn+0xa1/0x370
process_one_work+0x138/0x350
worker_thread+0x4d/0x3d0
kthread+0x109/0x140
ret_from_fork+0x25/0x30
The root cause here is, with IO alignment feature enables, in worst
case, we need F2FS_IO_SIZE() free blocks space for single one 4k write
due to IO alignment feature will fill dummy pages to make IO being
aligned.
So we will easily run out of free segments during non-inline directory's
data writeback, even in process of foreground GC.
In order to fix this issue, I just propose to reserve additional free
space for IO alignment feature to handle worst case of free space usage
ratio during FGGC.
Fixes: 0a595ebaaa6b ("f2fs: support IO alignment for DATA and NODE writes")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
-rw-r--r-- | fs/f2fs/f2fs.h | 11 | ||||
-rw-r--r-- | fs/f2fs/segment.h | 3 | ||||
-rw-r--r-- | fs/f2fs/super.c | 44 | ||||
-rw-r--r-- | fs/f2fs/sysfs.c | 4 |
4 files changed, 60 insertions, 2 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 8601d5e979d4..842020311f83 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1024,6 +1024,7 @@ struct f2fs_sm_info { unsigned int segment_count; /* total # of segments */ unsigned int main_segments; /* # of segments in main area */ unsigned int reserved_segments; /* # of reserved segments */ + unsigned int additional_reserved_segments;/* reserved segs for IO align feature */ unsigned int ovp_segments; /* # of overprovision segments */ /* a threshold to reclaim prefree segments */ @@ -2205,6 +2206,11 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi, if (!__allow_reserved_blocks(sbi, inode, true)) avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks; + + if (F2FS_IO_ALIGNED(sbi)) + avail_user_block_count -= sbi->blocks_per_seg * + SM_I(sbi)->additional_reserved_segments; + if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) { if (avail_user_block_count > sbi->unusable_block_count) avail_user_block_count -= sbi->unusable_block_count; @@ -2451,6 +2457,11 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi, if (!__allow_reserved_blocks(sbi, inode, false)) valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks; + + if (F2FS_IO_ALIGNED(sbi)) + valid_block_count += sbi->blocks_per_seg * + SM_I(sbi)->additional_reserved_segments; + user_block_count = sbi->user_block_count; if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) user_block_count -= sbi->unusable_block_count; diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 46fde9f3f28e..0291cd55cf09 100644 --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -538,7 +538,8 @@ static inline unsigned int free_segments(struct f2fs_sb_info *sbi) static inline unsigned int reserved_segments(struct f2fs_sb_info *sbi) { - return SM_I(sbi)->reserved_segments; + return SM_I(sbi)->reserved_segments + + SM_I(sbi)->additional_reserved_segments; } static inline unsigned int free_sections(struct f2fs_sb_info *sbi) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index ca5783fa56d5..053b508d1e4f 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -329,6 +329,46 @@ static inline void limit_reserve_root(struct f2fs_sb_info *sbi) F2FS_OPTION(sbi).s_resgid)); } +static inline int adjust_reserved_segment(struct f2fs_sb_info *sbi) +{ + unsigned int sec_blks = sbi->blocks_per_seg * sbi->segs_per_sec; + unsigned int avg_vblocks; + unsigned int wanted_reserved_segments; + block_t avail_user_block_count; + + if (!F2FS_IO_ALIGNED(sbi)) + return 0; + + /* average valid block count in section in worst case */ + avg_vblocks = sec_blks / F2FS_IO_SIZE(sbi); + + /* + * we need enough free space when migrating one section in worst case + */ + wanted_reserved_segments = (F2FS_IO_SIZE(sbi) / avg_vblocks) * + reserved_segments(sbi); + wanted_reserved_segments -= reserved_segments(sbi); + + avail_user_block_count = sbi->user_block_count - + sbi->current_reserved_blocks - + F2FS_OPTION(sbi).root_reserved_blocks; + + if (wanted_reserved_segments * sbi->blocks_per_seg > + avail_user_block_count) { + f2fs_err(sbi, "IO align feature can't grab additional reserved segment: %u, available segments: %u", + wanted_reserved_segments, + avail_user_block_count >> sbi->log_blocks_per_seg); + return -ENOSPC; + } + + SM_I(sbi)->additional_reserved_segments = wanted_reserved_segments; + + f2fs_info(sbi, "IO align feature needs additional reserved segment: %u", + wanted_reserved_segments); + + return 0; +} + static inline void adjust_unusable_cap_perc(struct f2fs_sb_info *sbi) { if (!F2FS_OPTION(sbi).unusable_cap_perc) @@ -4182,6 +4222,10 @@ try_onemore: goto free_nm; } + err = adjust_reserved_segment(sbi); + if (err) + goto free_nm; + /* For write statistics */ sbi->sectors_written_start = f2fs_get_sectors_written(sbi); diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 55a7df17d5f3..c22bee84c8ec 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -424,7 +424,9 @@ out: if (a->struct_type == RESERVED_BLOCKS) { spin_lock(&sbi->stat_lock); if (t > (unsigned long)(sbi->user_block_count - - F2FS_OPTION(sbi).root_reserved_blocks)) { + F2FS_OPTION(sbi).root_reserved_blocks - + sbi->blocks_per_seg * + SM_I(sbi)->additional_reserved_segments)) { spin_unlock(&sbi->stat_lock); return -EINVAL; } |