Commit 335d318e authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: bch2_folio_reservation_get_partial() is now better behaved 



bch2_folio_reservation_get_partial(), on partial success, will now
return a reservation that's aligned to the filesystem blocksize.

This is a partial fix for fstests generic/299 - fio verify is badly
behaved in the presence of short writes that aren't aligned to its
blocksize.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 81e0b6c7

fs/bcachefs/buckets.c

+5 −2
Original line number Diff line number Diff line
@@ -1160,11 +1160,11 @@ int bch2_trans_mark_dev_sbs(struct bch_fs *c) 
#define SECTORS_CACHE	1024



int __bch2_disk_reservation_add(struct bch_fs *c, struct disk_reservation *res,

			      u64 sectors, int flags)

				u64 sectors, enum bch_reservation_flags flags)

{

	struct bch_fs_pcpu *pcpu;

	u64 old, get;

	s64 sectors_available;

	u64 sectors_available;

	int ret;



	percpu_down_read(&c->mark_lock);
@@ -1202,6 +1202,9 @@ int __bch2_disk_reservation_add(struct bch_fs *c, struct disk_reservation *res, 
	percpu_u64_set(&c->pcpu->sectors_available, 0);

	sectors_available = avail_factor(__bch2_fs_usage_read_short(c).free);



	if (sectors_available && (flags & BCH_DISK_RESERVATION_PARTIAL))

		sectors = min(sectors, sectors_available);



	if (sectors <= sectors_available ||

	    (flags & BCH_DISK_RESERVATION_NOFAIL)) {

		atomic64_set(&c->sectors_available,

fs/bcachefs/buckets.h

+7 −5
Original line number Diff line number Diff line
@@ -344,14 +344,16 @@ static inline void bch2_disk_reservation_put(struct bch_fs *c, 
	}

}



#define BCH_DISK_RESERVATION_NOFAIL		(1 << 0)

enum bch_reservation_flags {

	BCH_DISK_RESERVATION_NOFAIL	= 1 << 0,

	BCH_DISK_RESERVATION_PARTIAL	= 1 << 1,

};



int __bch2_disk_reservation_add(struct bch_fs *,

				struct disk_reservation *,

				u64, int);

int __bch2_disk_reservation_add(struct bch_fs *, struct disk_reservation *,

				u64, enum bch_reservation_flags);



static inline int bch2_disk_reservation_add(struct bch_fs *c, struct disk_reservation *res,

					    u64 sectors, int flags)

					    u64 sectors, enum bch_reservation_flags flags)

{

#ifdef __KERNEL__

	u64 old, new;

fs/bcachefs/fs-io-pagecache.c

+45 −25
Original line number Diff line number Diff line
@@ -399,14 +399,17 @@ void bch2_folio_reservation_put(struct bch_fs *c, 
	bch2_quota_reservation_put(c, inode, &res->quota);

}



int bch2_folio_reservation_get(struct bch_fs *c,

static int __bch2_folio_reservation_get(struct bch_fs *c,

			struct bch_inode_info *inode,

			struct folio *folio,

			struct bch2_folio_reservation *res,

			size_t offset, size_t len)

			size_t offset, size_t len,

			bool partial)

{

	struct bch_folio *s = bch2_folio_create(folio, 0);

	unsigned i, disk_sectors = 0, quota_sectors = 0;

	struct disk_reservation disk_res = {};

	size_t reserved = len;

	int ret;



	if (!s)
@@ -422,48 +425,65 @@ int bch2_folio_reservation_get(struct bch_fs *c, 
	}



	if (disk_sectors) {

		ret = bch2_disk_reservation_add(c, &res->disk, disk_sectors, 0);

		ret = bch2_disk_reservation_add(c, &disk_res, disk_sectors,

				partial ? BCH_DISK_RESERVATION_PARTIAL : 0);

		if (unlikely(ret))

			return ret;



		if (unlikely(disk_res.sectors != disk_sectors)) {

			disk_sectors = quota_sectors = 0;



			for (i = round_down(offset, block_bytes(c)) >> 9;

			     i < round_up(offset + len, block_bytes(c)) >> 9;

			     i++) {

				disk_sectors += sectors_to_reserve(&s->s[i], res->disk.nr_replicas);

				if (disk_sectors > disk_res.sectors) {

					/*

					 * Make sure to get a reservation that's

					 * aligned to the filesystem blocksize:

					 */

					unsigned reserved_offset = round_down(i << 9, block_bytes(c));

					reserved = clamp(reserved_offset, offset, offset + len) - offset;



					if (!reserved) {

						bch2_disk_reservation_put(c, &disk_res);

						return -BCH_ERR_ENOSPC_disk_reservation;

					}

					break;

				}

				quota_sectors += s->s[i].state == SECTOR_unallocated;

			}

		}

	}



	if (quota_sectors) {

		ret = bch2_quota_reservation_add(c, inode, &res->quota, quota_sectors, true);

		if (unlikely(ret)) {

			struct disk_reservation tmp = { .sectors = disk_sectors };

			res->disk.sectors -= disk_sectors;



			bch2_disk_reservation_put(c, &tmp);

			bch2_disk_reservation_put(c, &disk_res);

			return ret;

		}

	}



	return 0;

	res->disk.sectors += disk_res.sectors;

	return partial ? reserved : 0;

}



ssize_t bch2_folio_reservation_get_partial(struct bch_fs *c,

int bch2_folio_reservation_get(struct bch_fs *c,

			struct bch_inode_info *inode,

			struct folio *folio,

			struct bch2_folio_reservation *res,

			size_t offset, size_t len)

{

	size_t l, reserved = 0;

	int ret;



	while ((l = len - reserved)) {

		while ((ret = bch2_folio_reservation_get(c, inode, folio, res, offset, l))) {

			if ((offset & (block_bytes(c) - 1)) + l <= block_bytes(c))

				return reserved ?: ret;



			len = reserved + l;

			l /= 2;

	return __bch2_folio_reservation_get(c, inode, folio, res, offset, len, false);

}



		offset += l;

		reserved += l;

	}



	return reserved;

ssize_t bch2_folio_reservation_get_partial(struct bch_fs *c,

			struct bch_inode_info *inode,

			struct folio *folio,

			struct bch2_folio_reservation *res,

			size_t offset, size_t len)

{

	return __bch2_folio_reservation_get(c, inode, folio, res, offset, len, true);

}



static void bch2_clear_folio_bits(struct folio *folio)