From: Chao Yu chao@kernel.org
commit 300a842937fbcfb5a189cea9ba15374fdb0b5c6b upstream.
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
--- fs/f2fs/f2fs.h | 11 +++++++++++ fs/f2fs/segment.h | 3 ++- fs/f2fs/super.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ fs/f2fs/sysfs.c | 4 +++- 4 files changed, 60 insertions(+), 2 deletions(-)
--- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -955,6 +955,7 @@ 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 */ @@ -1984,6 +1985,11 @@ static inline int inc_valid_block_count(
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; @@ -2229,6 +2235,11 @@ static inline int inc_valid_node_count(s
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; --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -539,7 +539,8 @@ static inline unsigned int free_segments
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) --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -289,6 +289,46 @@ static inline void limit_reserve_root(st 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) @@ -3736,6 +3776,10 @@ try_onemore: goto free_nm; }
+ err = adjust_reserved_segment(sbi); + if (err) + goto free_nm; + /* For write statistics */ if (sb->s_bdev->bd_part) sbi->sectors_written_start = --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -330,7 +330,9 @@ 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; }