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Commit fdc1ce97 authored by Chao Yu's avatar Chao Yu Committed by Greg Kroah-Hartman
Browse files

f2fs: fix to reserve space for IO align feature 

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
parent f852afb6

fs/f2fs/f2fs.h

+11 −0
Original line number Diff line number Diff line
@@ -931,6 +931,7 @@ 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 */
@@ -1800,6 +1801,11 @@ 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;
@@ -2045,6 +2051,11 @@ 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;

fs/f2fs/segment.h

+2 −1
Original line number Diff line number Diff line
@@ -508,7 +508,8 @@ static inline unsigned int free_segments(struct f2fs_sb_info *sbi) 


static inline 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)

fs/f2fs/super.c

+44 −0
Original line number Diff line number Diff line
@@ -277,6 +277,46 @@ 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)
@@ -3450,6 +3490,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) 
		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 =

fs/f2fs/sysfs.c

+3 −1
Original line number Diff line number Diff line
@@ -262,7 +262,9 @@ static ssize_t __sbi_store(struct f2fs_attr *a, 
	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;

		}