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authorKent Overstreet <kent.overstreet@linux.dev>2022-11-02 22:12:00 +0100
committerKent Overstreet <kent.overstreet@linux.dev>2023-10-22 23:09:51 +0200
commita8b3a677e786fa869d220a6a78b5532a36dc2f4d (patch)
tree3fdbdbb71945ae42dab8dc94971e1c78286eaa63
parentbcachefs: Data update support for unwritten extents (diff)
downloadlinux-a8b3a677e786fa869d220a6a78b5532a36dc2f4d.tar.xz
linux-a8b3a677e786fa869d220a6a78b5532a36dc2f4d.zip
bcachefs: Nocow support
This adds support for nocow mode, where we do writes in-place when possible. Patch components: - New boolean filesystem and inode option, nocow: note that when nocow is enabled, data checksumming and compression are implicitly disabled - To prevent in-place writes from racing with data moves (data_update.c) or bucket reuse (i.e. a bucket being reused and re-allocated while a nocow write is in flight, we have a new locking mechanism. Buckets can be locked for either data update or data move, using a fixed size hash table of two_state_shared locks. We don't have any chaining, meaning updates and moves to different buckets that hash to the same lock will wait unnecessarily - we'll want to watch for this becoming an issue. - The allocator path also needs to check for in-place writes in flight to a given bucket before giving it out: thus we add another counter to bucket_alloc_state so we can track this. - Fsync now may need to issue cache flushes to block devices instead of flushing the journal. We add a device bitmask to bch_inode_info, ei_devs_need_flush, which tracks devices that need to have flushes issued - note that this will lead to unnecessary flushes when other codepaths have already issued flushes, we may want to replace this with a sequence number. - New nocow write path: look up extents, and if they're writable write to them - otherwise fall back to the normal COW write path. XXX: switch to sequence numbers instead of bitmask for devs needing journal flush XXX: ei_quota_lock being a mutex means bch2_nocow_write_done() needs to run in process context - see if we can improve this Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
-rw-r--r--fs/bcachefs/Makefile1
-rw-r--r--fs/bcachefs/alloc_foreground.c5
-rw-r--r--fs/bcachefs/alloc_types.h1
-rw-r--r--fs/bcachefs/bcachefs.h10
-rw-r--r--fs/bcachefs/bcachefs_format.h10
-rw-r--r--fs/bcachefs/btree_io.c3
-rw-r--r--fs/bcachefs/checksum.h7
-rw-r--r--fs/bcachefs/data_update.c10
-rw-r--r--fs/bcachefs/extents.c39
-rw-r--r--fs/bcachefs/extents.h1
-rw-r--r--fs/bcachefs/fs-io.c98
-rw-r--r--fs/bcachefs/fs.h11
-rw-r--r--fs/bcachefs/inode.c3
-rw-r--r--fs/bcachefs/io.c452
-rw-r--r--fs/bcachefs/io.h7
-rw-r--r--fs/bcachefs/io_types.h7
-rw-r--r--fs/bcachefs/move.c7
-rw-r--r--fs/bcachefs/nocow_locking.c15
-rw-r--r--fs/bcachefs/nocow_locking.h55
-rw-r--r--fs/bcachefs/opts.h7
-rw-r--r--fs/bcachefs/super.h7
-rw-r--r--fs/bcachefs/trace.h5
22 files changed, 709 insertions, 52 deletions
diff --git a/fs/bcachefs/Makefile b/fs/bcachefs/Makefile
index 456d540441ce..55b6d85d55c3 100644
--- a/fs/bcachefs/Makefile
+++ b/fs/bcachefs/Makefile
@@ -52,6 +52,7 @@ bcachefs-y := \
migrate.o \
move.o \
movinggc.o \
+ nocow_locking.o \
opts.o \
printbuf.o \
quota.o \
diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index a179bbe23c93..f78eaa52c11f 100644
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -227,6 +227,11 @@ static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *
return NULL;
}
+ if (bch2_bucket_nocow_is_locked(&c->nocow_locks, POS(ca->dev_idx, bucket))) {
+ s->skipped_nocow++;
+ return NULL;
+ }
+
spin_lock(&c->freelist_lock);
if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(reserve))) {
diff --git a/fs/bcachefs/alloc_types.h b/fs/bcachefs/alloc_types.h
index 2c96794d1993..2e6f48069258 100644
--- a/fs/bcachefs/alloc_types.h
+++ b/fs/bcachefs/alloc_types.h
@@ -12,6 +12,7 @@ struct bucket_alloc_state {
u64 buckets_seen;
u64 skipped_open;
u64 skipped_need_journal_commit;
+ u64 skipped_nocow;
u64 skipped_nouse;
};
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 6d048e5d8843..74632105fb45 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -206,6 +206,7 @@
#include "bcachefs_format.h"
#include "errcode.h"
#include "fifo.h"
+#include "nocow_locking.h"
#include "opts.h"
#include "util.h"
@@ -383,7 +384,8 @@ BCH_DEBUG_PARAMS_DEBUG()
x(journal_flush_seq) \
x(blocked_journal) \
x(blocked_allocate) \
- x(blocked_allocate_open_bucket)
+ x(blocked_allocate_open_bucket) \
+ x(nocow_lock_contended)
enum bch_time_stats {
#define x(name) BCH_TIME_##name,
@@ -483,6 +485,7 @@ struct bch_dev {
struct bch_sb *sb_read_scratch;
int sb_write_error;
dev_t dev;
+ atomic_t flush_seq;
struct bch_devs_mask self;
@@ -897,7 +900,9 @@ struct bch_fs {
struct bio_set bio_read_split;
struct bio_set bio_write;
struct mutex bio_bounce_pages_lock;
-mempool_t bio_bounce_pages;
+ mempool_t bio_bounce_pages;
+ struct bucket_nocow_lock_table
+ nocow_locks;
struct rhashtable promote_table;
mempool_t compression_bounce[2];
@@ -959,6 +964,7 @@ mempool_t bio_bounce_pages;
struct bio_set writepage_bioset;
struct bio_set dio_write_bioset;
struct bio_set dio_read_bioset;
+ struct bio_set nocow_flush_bioset;
/* ERRORS */
struct list_head fsck_errors;
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 57327c4dc9b4..024a714955f2 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -798,7 +798,8 @@ struct bch_inode_generation {
x(bi_dir, 64) \
x(bi_dir_offset, 64) \
x(bi_subvol, 32) \
- x(bi_parent_subvol, 32)
+ x(bi_parent_subvol, 32) \
+ x(bi_nocow, 8)
/* subset of BCH_INODE_FIELDS */
#define BCH_INODE_OPTS() \
@@ -810,7 +811,8 @@ struct bch_inode_generation {
x(promote_target, 16) \
x(foreground_target, 16) \
x(background_target, 16) \
- x(erasure_code, 16)
+ x(erasure_code, 16) \
+ x(nocow, 8)
enum inode_opt_id {
#define x(name, ...) \
@@ -1548,7 +1550,8 @@ struct bch_sb_field_journal_seq_blacklist {
x(alloc_v4, 20) \
x(new_data_types, 21) \
x(backpointers, 22) \
- x(inode_v3, 23)
+ x(inode_v3, 23) \
+ x(unwritten_extents, 24)
enum bcachefs_metadata_version {
bcachefs_metadata_version_min = 9,
@@ -1696,6 +1699,7 @@ LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
+LE64_BITMASK(BCH_SB_NOCOW, struct bch_sb, flags[4], 33, 34);
LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE, struct bch_sb, flags[4], 34, 54);
/*
diff --git a/fs/bcachefs/btree_io.c b/fs/bcachefs/btree_io.c
index dfa45cf4021f..87d80a59dd7e 100644
--- a/fs/bcachefs/btree_io.c
+++ b/fs/bcachefs/btree_io.c
@@ -1832,7 +1832,8 @@ static void btree_write_submit(struct work_struct *work)
bkey_for_each_ptr(bch2_bkey_ptrs(bkey_i_to_s(&tmp.k)), ptr)
ptr->offset += wbio->sector_offset;
- bch2_submit_wbio_replicas(&wbio->wbio, wbio->wbio.c, BCH_DATA_btree, &tmp.k);
+ bch2_submit_wbio_replicas(&wbio->wbio, wbio->wbio.c, BCH_DATA_btree,
+ &tmp.k, false);
}
void __bch2_btree_node_write(struct bch_fs *c, struct btree *b, unsigned flags)
diff --git a/fs/bcachefs/checksum.h b/fs/bcachefs/checksum.h
index f7ccef7a5520..409ad534d9f4 100644
--- a/fs/bcachefs/checksum.h
+++ b/fs/bcachefs/checksum.h
@@ -99,14 +99,17 @@ static inline enum bch_csum_type bch2_csum_opt_to_type(enum bch_csum_opts type,
}
static inline enum bch_csum_type bch2_data_checksum_type(struct bch_fs *c,
- unsigned opt)
+ struct bch_io_opts opts)
{
+ if (opts.nocow)
+ return 0;
+
if (c->sb.encryption_type)
return c->opts.wide_macs
? BCH_CSUM_chacha20_poly1305_128
: BCH_CSUM_chacha20_poly1305_80;
- return bch2_csum_opt_to_type(opt, true);
+ return bch2_csum_opt_to_type(opts.data_checksum, true);
}
static inline enum bch_csum_type bch2_meta_checksum_type(struct bch_fs *c)
diff --git a/fs/bcachefs/data_update.c b/fs/bcachefs/data_update.c
index 82d7e13e61a5..c3f12b3adb14 100644
--- a/fs/bcachefs/data_update.c
+++ b/fs/bcachefs/data_update.c
@@ -303,6 +303,13 @@ void bch2_data_update_read_done(struct data_update *m,
void bch2_data_update_exit(struct data_update *update)
{
struct bch_fs *c = update->op.c;
+ struct bkey_ptrs_c ptrs =
+ bch2_bkey_ptrs_c(bkey_i_to_s_c(update->k.k));
+ const struct bch_extent_ptr *ptr;
+
+ bkey_for_each_ptr(ptrs, ptr)
+ bch2_bucket_nocow_unlock(&c->nocow_locks,
+ PTR_BUCKET_POS(c, ptr), 0);
bch2_bkey_buf_exit(&update->k, c);
bch2_disk_reservation_put(c, &update->op.res);
@@ -451,6 +458,9 @@ int bch2_data_update_init(struct bch_fs *c, struct data_update *m,
m->op.incompressible = true;
i++;
+
+ bch2_bucket_nocow_lock(&c->nocow_locks,
+ PTR_BUCKET_POS(c, &p.ptr), 0);
}
if (reserve_sectors) {
diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index 627edba24900..55a8879dc4fe 100644
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -664,22 +664,21 @@ unsigned bch2_bkey_replicas(struct bch_fs *c, struct bkey_s_c k)
return replicas;
}
-static unsigned bch2_extent_ptr_durability(struct bch_fs *c,
- struct extent_ptr_decoded p)
+unsigned bch2_extent_ptr_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
{
unsigned durability = 0;
struct bch_dev *ca;
- if (p.ptr.cached)
+ if (p->ptr.cached)
return 0;
- ca = bch_dev_bkey_exists(c, p.ptr.dev);
+ ca = bch_dev_bkey_exists(c, p->ptr.dev);
if (ca->mi.state != BCH_MEMBER_STATE_failed)
durability = max_t(unsigned, durability, ca->mi.durability);
- if (p.has_ec)
- durability += p.ec.redundancy;
+ if (p->has_ec)
+ durability += p->ec.redundancy;
return durability;
}
@@ -692,7 +691,7 @@ unsigned bch2_bkey_durability(struct bch_fs *c, struct bkey_s_c k)
unsigned durability = 0;
bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
- durability += bch2_extent_ptr_durability(c, p);
+ durability += bch2_extent_ptr_durability(c,& p);
return durability;
}
@@ -907,23 +906,31 @@ bool bch2_bkey_matches_ptr(struct bch_fs *c, struct bkey_s_c k,
*/
bool bch2_extents_match(struct bkey_s_c k1, struct bkey_s_c k2)
{
- struct bkey_ptrs_c ptrs1 = bch2_bkey_ptrs_c(k1);
- struct bkey_ptrs_c ptrs2 = bch2_bkey_ptrs_c(k2);
- const union bch_extent_entry *entry1, *entry2;
- struct extent_ptr_decoded p1, p2;
-
- if (bkey_extent_is_unwritten(k1) != bkey_extent_is_unwritten(k2))
+ if (k1.k->type != k2.k->type)
return false;
- bkey_for_each_ptr_decode(k1.k, ptrs1, p1, entry1)
- bkey_for_each_ptr_decode(k2.k, ptrs2, p2, entry2)
+ if (bkey_extent_is_direct_data(k1.k)) {
+ struct bkey_ptrs_c ptrs1 = bch2_bkey_ptrs_c(k1);
+ struct bkey_ptrs_c ptrs2 = bch2_bkey_ptrs_c(k2);
+ const union bch_extent_entry *entry1, *entry2;
+ struct extent_ptr_decoded p1, p2;
+
+ if (bkey_extent_is_unwritten(k1) != bkey_extent_is_unwritten(k2))
+ return false;
+
+ bkey_for_each_ptr_decode(k1.k, ptrs1, p1, entry1)
+ bkey_for_each_ptr_decode(k2.k, ptrs2, p2, entry2)
if (p1.ptr.dev == p2.ptr.dev &&
p1.ptr.gen == p2.ptr.gen &&
(s64) p1.ptr.offset + p1.crc.offset - bkey_start_offset(k1.k) ==
(s64) p2.ptr.offset + p2.crc.offset - bkey_start_offset(k2.k))
return true;
- return false;
+ return false;
+ } else {
+ /* KEY_TYPE_deleted, etc. */
+ return true;
+ }
}
bool bch2_extent_has_ptr(struct bkey_s_c k1, struct extent_ptr_decoded p1,
diff --git a/fs/bcachefs/extents.h b/fs/bcachefs/extents.h
index 659ab76ea62c..e27d39b728b3 100644
--- a/fs/bcachefs/extents.h
+++ b/fs/bcachefs/extents.h
@@ -596,6 +596,7 @@ bool bch2_bkey_is_incompressible(struct bkey_s_c);
unsigned bch2_bkey_sectors_compressed(struct bkey_s_c);
unsigned bch2_bkey_replicas(struct bch_fs *, struct bkey_s_c);
+unsigned bch2_extent_ptr_durability(struct bch_fs *, struct extent_ptr_decoded *);
unsigned bch2_bkey_durability(struct bch_fs *, struct bkey_s_c);
void bch2_bkey_drop_device(struct bkey_s, unsigned);
diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c
index b5cf0a3218ea..ec575b27eedb 100644
--- a/fs/bcachefs/fs-io.c
+++ b/fs/bcachefs/fs-io.c
@@ -35,6 +35,72 @@
#include <trace/events/writeback.h>
+struct nocow_flush {
+ struct closure *cl;
+ struct bch_dev *ca;
+ struct bio bio;
+};
+
+static void nocow_flush_endio(struct bio *_bio)
+{
+
+ struct nocow_flush *bio = container_of(_bio, struct nocow_flush, bio);
+
+ closure_put(bio->cl);
+ percpu_ref_put(&bio->ca->io_ref);
+ bio_put(&bio->bio);
+}
+
+static void bch2_inode_flush_nocow_writes_async(struct bch_fs *c,
+ struct bch_inode_info *inode,
+ struct closure *cl)
+{
+ struct nocow_flush *bio;
+ struct bch_dev *ca;
+ struct bch_devs_mask devs;
+ unsigned dev;
+
+ dev = find_first_bit(inode->ei_devs_need_flush.d, BCH_SB_MEMBERS_MAX);
+ if (dev == BCH_SB_MEMBERS_MAX)
+ return;
+
+ devs = inode->ei_devs_need_flush;
+ memset(&inode->ei_devs_need_flush, 0, sizeof(inode->ei_devs_need_flush));
+
+ for_each_set_bit(dev, devs.d, BCH_SB_MEMBERS_MAX) {
+ rcu_read_lock();
+ ca = rcu_dereference(c->devs[dev]);
+ if (ca && !percpu_ref_tryget(&ca->io_ref))
+ ca = NULL;
+ rcu_read_unlock();
+
+ if (!ca)
+ continue;
+
+ bio = container_of(bio_alloc_bioset(ca->disk_sb.bdev, 0,
+ REQ_OP_FLUSH,
+ GFP_KERNEL,
+ &c->nocow_flush_bioset),
+ struct nocow_flush, bio);
+ bio->cl = cl;
+ bio->ca = ca;
+ bio->bio.bi_end_io = nocow_flush_endio;
+ closure_bio_submit(&bio->bio, cl);
+ }
+}
+
+static int bch2_inode_flush_nocow_writes(struct bch_fs *c,
+ struct bch_inode_info *inode)
+{
+ struct closure cl;
+
+ closure_init_stack(&cl);
+ bch2_inode_flush_nocow_writes_async(c, inode, &cl);
+ closure_sync(&cl);
+
+ return 0;
+}
+
static inline bool bio_full(struct bio *bio, unsigned len)
{
if (bio->bi_vcnt >= bio->bi_max_vecs)
@@ -1327,6 +1393,7 @@ static void bch2_writepage_io_alloc(struct bch_fs *c,
op->subvol = inode->ei_subvol;
op->pos = POS(inode->v.i_ino, sector);
op->end_io = bch2_writepage_io_done;
+ op->devs_need_flush = &inode->ei_devs_need_flush;
op->wbio.bio.bi_iter.bi_sector = sector;
op->wbio.bio.bi_opf = wbc_to_write_flags(wbc);
}
@@ -2148,10 +2215,12 @@ static noinline void bch2_dio_write_flush(struct dio_write *dio)
if (!dio->op.error) {
ret = bch2_inode_find_by_inum(c, inode_inum(dio->inode), &inode);
- if (ret)
+ if (ret) {
dio->op.error = ret;
- else
+ } else {
bch2_journal_flush_seq_async(&c->journal, inode.bi_journal_seq, &dio->op.cl);
+ bch2_inode_flush_nocow_writes_async(c, dio->inode, &dio->op.cl);
+ }
}
if (dio->sync) {
@@ -2296,6 +2365,7 @@ static __always_inline long bch2_dio_write_loop(struct dio_write *dio)
dio->op.nr_replicas = dio->op.opts.data_replicas;
dio->op.subvol = inode->ei_subvol;
dio->op.pos = POS(inode->v.i_ino, (u64) req->ki_pos >> 9);
+ dio->op.devs_need_flush = &inode->ei_devs_need_flush;
if (sync)
dio->op.flags |= BCH_WRITE_SYNC;
@@ -2495,19 +2565,21 @@ out:
* inode->ei_inode.bi_journal_seq won't be up to date since it's set in an
* insert trigger: look up the btree inode instead
*/
-static int bch2_flush_inode(struct bch_fs *c, subvol_inum inum)
+static int bch2_flush_inode(struct bch_fs *c,
+ struct bch_inode_info *inode)
{
- struct bch_inode_unpacked inode;
+ struct bch_inode_unpacked u;
int ret;
if (c->opts.journal_flush_disabled)
return 0;
- ret = bch2_inode_find_by_inum(c, inum, &inode);
+ ret = bch2_inode_find_by_inum(c, inode_inum(inode), &u);
if (ret)
return ret;
- return bch2_journal_flush_seq(&c->journal, inode.bi_journal_seq);
+ return bch2_journal_flush_seq(&c->journal, u.bi_journal_seq) ?:
+ bch2_inode_flush_nocow_writes(c, inode);
}
int bch2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
@@ -2518,7 +2590,7 @@ int bch2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
ret = file_write_and_wait_range(file, start, end);
ret2 = sync_inode_metadata(&inode->v, 1);
- ret3 = bch2_flush_inode(c, inode_inum(inode));
+ ret3 = bch2_flush_inode(c, inode);
return bch2_err_class(ret ?: ret2 ?: ret3);
}
@@ -3105,6 +3177,11 @@ static int __bchfs_fallocate(struct bch_inode_info *inode, int mode,
continue;
}
+ /*
+ * XXX: for nocow mode, we should promote shared extents to
+ * unshared here
+ */
+
sectors = bpos_min(k.k->p, end_pos).offset - iter.pos.offset;
if (!bkey_extent_is_allocation(k.k)) {
@@ -3368,7 +3445,7 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
if ((file_dst->f_flags & (__O_SYNC | O_DSYNC)) ||
IS_SYNC(file_inode(file_dst)))
- ret = bch2_flush_inode(c, inode_inum(dst));
+ ret = bch2_flush_inode(c, dst);
err:
bch2_quota_reservation_put(c, dst, &quota_res);
bch2_unlock_inodes(INODE_LOCK|INODE_PAGECACHE_BLOCK, src, dst);
@@ -3622,6 +3699,7 @@ loff_t bch2_llseek(struct file *file, loff_t offset, int whence)
void bch2_fs_fsio_exit(struct bch_fs *c)
{
+ bioset_exit(&c->nocow_flush_bioset);
bioset_exit(&c->dio_write_bioset);
bioset_exit(&c->dio_read_bioset);
bioset_exit(&c->writepage_bioset);
@@ -3641,7 +3719,9 @@ int bch2_fs_fsio_init(struct bch_fs *c)
BIOSET_NEED_BVECS) ||
bioset_init(&c->dio_write_bioset,
4, offsetof(struct dio_write, op.wbio.bio),
- BIOSET_NEED_BVECS))
+ BIOSET_NEED_BVECS) ||
+ bioset_init(&c->nocow_flush_bioset,
+ 1, offsetof(struct nocow_flush, bio), 0))
ret = -ENOMEM;
pr_verbose_init(c->opts, "ret %i", ret);
diff --git a/fs/bcachefs/fs.h b/fs/bcachefs/fs.h
index 4164d0669d70..e1c73a38c607 100644
--- a/fs/bcachefs/fs.h
+++ b/fs/bcachefs/fs.h
@@ -25,6 +25,17 @@ struct bch_inode_info {
u32 ei_subvol;
+ /*
+ * When we've been doing nocow writes we'll need to issue flushes to the
+ * underlying block devices
+ *
+ * XXX: a device may have had a flush issued by some other codepath. It
+ * would be better to keep for each device a sequence number that's
+ * incremented when we isusue a cache flush, and track here the sequence
+ * number that needs flushing.
+ */
+ struct bch_devs_mask ei_devs_need_flush;
+
/* copy of inode in btree: */
struct bch_inode_unpacked ei_inode;
};
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index f338cf6fd8b7..a98e40065122 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -892,4 +892,7 @@ void bch2_inode_opts_get(struct bch_io_opts *opts, struct bch_fs *c,
#define x(_name, _bits) opts->_name = inode_opt_get(c, inode, _name);
BCH_INODE_OPTS()
#undef x
+
+ if (opts->nocow)
+ opts->compression = opts->background_compression = opts->data_checksum = opts->erasure_code = 0;
}
diff --git a/fs/bcachefs/io.c b/fs/bcachefs/io.c
index 1d0ec638f645..d511bd664953 100644
--- a/fs/bcachefs/io.c
+++ b/fs/bcachefs/io.c
@@ -34,6 +34,7 @@
#include "trace.h"
#include <linux/blkdev.h>
+#include <linux/prefetch.h>
#include <linux/random.h>
#include <linux/sched/mm.h>
@@ -375,24 +376,118 @@ int bch2_extent_fallocate(struct btree_trans *trans,
s64 *i_sectors_delta,
struct write_point_specifier write_point)
{
- int ret;
struct bch_fs *c = trans->c;
struct disk_reservation disk_res = { 0 };
- struct bkey_i_reservation *reservation =
- bch2_trans_kmalloc(trans, sizeof(*reservation));
+ struct closure cl;
+ struct open_buckets open_buckets;
+ struct bkey_s_c k;
+ struct bkey_buf old, new;
+ bool have_reservation = false;
+ bool unwritten = opts.nocow &&
+ c->sb.version >= bcachefs_metadata_version_unwritten_extents;
+ int ret;
- ret = PTR_ERR_OR_ZERO(reservation);
+ bch2_bkey_buf_init(&old);
+ bch2_bkey_buf_init(&new);
+ closure_init_stack(&cl);
+ open_buckets.nr = 0;
+retry:
+ k = bch2_btree_iter_peek_slot(iter);
+ ret = bkey_err(k);
if (ret)
return ret;
- bkey_reservation_init(&reservation->k_i);
- reservation->k.p = iter->pos;
- bch2_key_resize(&reservation->k, sectors);
- reservation->v.nr_replicas = opts.data_replicas;
+ sectors = min_t(u64, sectors, k.k->p.offset - iter->pos.offset);
+
+ if (!have_reservation) {
+ unsigned new_replicas =
+ max(0, (int) opts.data_replicas -
+ (int) bch2_bkey_nr_ptrs_fully_allocated(k));
+ /*
+ * Get a disk reservation before (in the nocow case) calling
+ * into the allocator:
+ */
+ ret = bch2_disk_reservation_get(c, &disk_res, sectors, new_replicas, 0);
+ if (unlikely(ret))
+ goto out;
+
+ bch2_bkey_buf_reassemble(&old, c, k);
+ }
+
+ if (have_reservation) {
+ if (!bch2_extents_match(k, bkey_i_to_s_c(old.k)))
+ goto out;
+
+ bch2_key_resize(&new.k->k, sectors);
+ } else if (!unwritten) {
+ struct bkey_i_reservation *reservation;
+
+ bch2_bkey_buf_realloc(&new, c, sizeof(*reservation) / sizeof(u64));
+ reservation = bkey_reservation_init(new.k);
+ reservation->k.p = iter->pos;
+ bch2_key_resize(&reservation->k, sectors);
+ reservation->v.nr_replicas = opts.data_replicas;
+ } else {
+ struct bkey_i_extent *e;
+ struct bch_devs_list devs_have;
+ struct write_point *wp;
+ struct bch_extent_ptr *ptr;
+
+ devs_have.nr = 0;
+
+ bch2_bkey_buf_realloc(&new, c, BKEY_EXTENT_U64s_MAX);
+
+ e = bkey_extent_init(new.k);
+ e->k.p = iter->pos;
+
+ ret = bch2_alloc_sectors_start_trans(trans,
+ opts.foreground_target,
+ false,
+ write_point,
+ &devs_have,
+ opts.data_replicas,
+ opts.data_replicas,
+ RESERVE_none, 0, &cl, &wp);
+ if (bch2_err_matches(ret, BCH_ERR_operation_blocked)) {
+ bch2_trans_unlock(trans);
+ closure_sync(&cl);
+ goto retry;
+ }
+ if (ret)
+ return ret;
+
+ sectors = min(sectors, wp->sectors_free);
+
+ bch2_key_resize(&e->k, sectors);
+
+ bch2_open_bucket_get(c, wp, &open_buckets);
+ bch2_alloc_sectors_append_ptrs(c, wp, &e->k_i, sectors, false);
+ bch2_alloc_sectors_done(c, wp);
+
+ extent_for_each_ptr(extent_i_to_s(e), ptr)
+ ptr->unwritten = true;
+ }
+
+ have_reservation = true;
- ret = bch2_extent_update(trans, inum, iter, &reservation->k_i, &disk_res,
+ ret = bch2_extent_update(trans, inum, iter, new.k, &disk_res,
0, i_sectors_delta, true);
+out:
+ if ((atomic_read(&cl.remaining) & CLOSURE_REMAINING_MASK) != 1) {
+ bch2_trans_unlock(trans);
+ closure_sync(&cl);
+ }
+
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
+ bch2_trans_begin(trans);
+ goto retry;
+ }
+
+ bch2_open_buckets_put(c, &open_buckets);
bch2_disk_reservation_put(c, &disk_res);
+ bch2_bkey_buf_exit(&new, c);
+ bch2_bkey_buf_exit(&old, c);
+
return ret;
}
@@ -539,7 +634,8 @@ static int bch2_write_index_default(struct bch_write_op *op)
void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
enum bch_data_type type,
- const struct bkey_i *k)
+ const struct bkey_i *k,
+ bool nocow)
{
struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
const struct bch_extent_ptr *ptr;
@@ -573,8 +669,9 @@ void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
n->c = c;
n->dev = ptr->dev;
- n->have_ioref = bch2_dev_get_ioref(ca,
+ n->have_ioref = nocow || bch2_dev_get_ioref(ca,
type == BCH_DATA_btree ? READ : WRITE);
+ n->nocow = nocow;
n->submit_time = local_clock();
n->inode_offset = bkey_start_offset(&k->k);
n->bio.bi_iter.bi_sector = ptr->offset;
@@ -801,6 +898,9 @@ static void bch2_write_endio(struct bio *bio)
op->flags |= BCH_WRITE_IO_ERROR;
}
+ if (wbio->nocow)
+ set_bit(wbio->dev, op->devs_need_flush->d);
+
if (wbio->have_ioref) {
bch2_latency_acct(ca, wbio->submit_time, WRITE);
percpu_ref_put(&ca->io_ref);
@@ -1221,6 +1321,321 @@ err:
return ret;
}
+static bool bch2_extent_is_writeable(struct bch_write_op *op,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = op->c;
+ struct bkey_s_c_extent e;
+ struct extent_ptr_decoded p;
+ const union bch_extent_entry *entry;
+ unsigned replicas = 0;
+
+ if (k.k->type != KEY_TYPE_extent)
+ return false;
+
+ e = bkey_s_c_to_extent(k);
+ extent_for_each_ptr_decode(e, p, entry) {
+ if (p.crc.csum_type ||
+ crc_is_compressed(p.crc) ||
+ p.has_ec)
+ return false;
+
+ replicas += bch2_extent_ptr_durability(c, &p);
+ }
+
+ return replicas >= op->opts.data_replicas;
+}
+
+static inline void bch2_nocow_write_unlock(struct bch_write_op *op)
+{
+ struct bch_fs *c = op->c;
+ const struct bch_extent_ptr *ptr;
+ struct bkey_i *k;
+
+ for_each_keylist_key(&op->insert_keys, k) {
+ struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
+
+ bkey_for_each_ptr(ptrs, ptr)
+ bch2_bucket_nocow_unlock(&c->nocow_locks,
+ PTR_BUCKET_POS(c, ptr),
+ BUCKET_NOCOW_LOCK_UPDATE);
+ }
+}
+
+static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_i *orig,
+ struct bkey_s_c k,
+ u64 new_i_size)
+{
+ struct bkey_i *new;
+ struct bkey_ptrs ptrs;
+ struct bch_extent_ptr *ptr;
+ int ret;
+
+ if (!bch2_extents_match(bkey_i_to_s_c(orig), k)) {
+ /* trace this */
+ return 0;
+ }
+
+ new = bch2_bkey_make_mut(trans, k);
+ ret = PTR_ERR_OR_ZERO(new);
+ if (ret)
+ return ret;
+
+ bch2_cut_front(bkey_start_pos(&orig->k), new);
+ bch2_cut_back(orig->k.p, new);
+
+ ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
+ bkey_for_each_ptr(ptrs, ptr)
+ ptr->unwritten = 0;
+
+ /*
+ * Note that we're not calling bch2_subvol_get_snapshot() in this path -
+ * that was done when we kicked off the write, and here it's important
+ * that we update the extent that we wrote to - even if a snapshot has
+ * since been created. The write is still outstanding, so we're ok
+ * w.r.t. snapshot atomicity:
+ */
+ return bch2_extent_update_i_size_sectors(trans, iter,
+ min(new->k.p.offset << 9, new_i_size), 0) ?:
+ bch2_trans_update(trans, iter, new,
+ BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+}
+
+static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
+{
+ struct bch_fs *c = op->c;
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_i *orig;
+ struct bkey_s_c k;
+ int ret;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ for_each_keylist_key(&op->insert_keys, orig) {
+ ret = for_each_btree_key_upto_commit(&trans, iter, BTREE_ID_extents,
+ bkey_start_pos(&orig->k), orig->k.p,
+ BTREE_ITER_INTENT, k,
+ NULL, NULL, BTREE_INSERT_NOFAIL, ({
+ bch2_nocow_write_convert_one_unwritten(&trans, &iter, orig, k, op->new_i_size);
+ }));
+
+ if (ret && !bch2_err_matches(ret, EROFS)) {
+ struct bkey_i *k = bch2_keylist_front(&op->insert_keys);
+
+ bch_err_inum_offset_ratelimited(c,
+ k->k.p.inode, k->k.p.offset << 9,
+ "write error while doing btree update: %s",
+ bch2_err_str(ret));
+ }
+
+ if (ret) {
+ op->error = ret;
+ break;
+ }
+ }
+
+ bch2_trans_exit(&trans);
+}
+
+static void __bch2_nocow_write_done(struct bch_write_op *op)
+{
+ bch2_nocow_write_unlock(op);
+
+ if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
+ op->error = -EIO;
+ } else if (unlikely(op->flags & BCH_WRITE_CONVERT_UNWRITTEN))
+ bch2_nocow_write_convert_unwritten(op);
+}
+
+static void bch2_nocow_write_done(struct closure *cl)
+{
+ struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
+
+ __bch2_nocow_write_done(op);
+ bch2_write_done(cl);
+}
+
+static void bch2_nocow_write(struct bch_write_op *op)
+{
+ struct bch_fs *c = op->c;
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_ptrs_c ptrs;
+ const struct bch_extent_ptr *ptr, *ptr2;
+ struct {
+ struct bpos b;
+ unsigned gen;
+ two_state_lock_t *l;
+ } buckets[BCH_REPLICAS_MAX];
+ unsigned nr_buckets = 0;
+ u32 snapshot;
+ int ret, i;
+
+ if (op->flags & BCH_WRITE_MOVE)
+ return;
+
+ bch2_trans_init(&trans, c, 0, 0);
+retry:
+ bch2_trans_begin(&trans);
+
+ ret = bch2_subvolume_get_snapshot(&trans, op->subvol, &snapshot);
+ if (unlikely(ret))
+ goto err;
+
+ bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
+ SPOS(op->pos.inode, op->pos.offset, snapshot),
+ BTREE_ITER_SLOTS);
+ while (1) {
+ struct bio *bio = &op->wbio.bio;
+
+ nr_buckets = 0;
+
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ break;
+
+ /* fall back to normal cow write path? */
+ if (unlikely(k.k->p.snapshot != snapshot ||
+ !bch2_extent_is_writeable(op, k)))
+ break;
+
+ if (bch2_keylist_realloc(&op->insert_keys,
+ op->inline_keys,
+ ARRAY_SIZE(op->inline_keys),
+ k.k->u64s))
+ break;
+
+ /* Get iorefs before dropping btree locks: */
+ ptrs = bch2_bkey_ptrs_c(k);
+ bkey_for_each_ptr(ptrs, ptr) {
+ buckets[nr_buckets].b = PTR_BUCKET_POS(c, ptr);
+ buckets[nr_buckets].gen = ptr->gen;
+ buckets[nr_buckets].l =
+ bucket_nocow_lock(&c->nocow_locks, buckets[nr_buckets].b);
+
+ prefetch(buckets[nr_buckets].l);
+ nr_buckets++;
+
+ if (unlikely(!bch2_dev_get_ioref(bch_dev_bkey_exists(c, ptr->dev), WRITE)))
+ goto err_get_ioref;
+
+ if (ptr->unwritten)
+ op->flags |= BCH_WRITE_CONVERT_UNWRITTEN;
+ }
+
+ /* Unlock before taking nocow locks, doing IO: */
+ bkey_reassemble(op->insert_keys.top, k);
+ bch2_trans_unlock(&trans);
+
+ bch2_cut_front(op->pos, op->insert_keys.top);
+ if (op->flags & BCH_WRITE_CONVERT_UNWRITTEN)
+ bch2_cut_back(POS(op->pos.inode, op->pos.offset + bio_sectors(bio)), op->insert_keys.top);
+
+ for (i = 0; i < nr_buckets; i++) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, buckets[i].b.inode);
+ two_state_lock_t *l = buckets[i].l;
+ bool stale;
+
+ if (!bch2_two_state_trylock(l, BUCKET_NOCOW_LOCK_UPDATE))
+ __bch2_bucket_nocow_lock(&c->nocow_locks, l, BUCKET_NOCOW_LOCK_UPDATE);
+
+ rcu_read_lock();
+ stale = gen_after(*bucket_gen(ca, buckets[i].b.offset), buckets[i].gen);
+ rcu_read_unlock();
+
+ if (unlikely(stale))
+ goto err_bucket_stale;
+ }
+
+ bio = &op->wbio.bio;
+ if (k.k->p.offset < op->pos.offset + bio_sectors(bio)) {
+ bio = bio_split(bio, k.k->p.offset - op->pos.offset,
+ GFP_KERNEL, &c->bio_write);
+ wbio_init(bio)->put_bio = true;
+ bio->bi_opf = op->wbio.bio.bi_opf;
+ } else {
+ op->flags |= BCH_WRITE_DONE;
+ }
+
+ op->pos.offset += bio_sectors(bio);
+ op->written += bio_sectors(bio);
+
+ bio->bi_end_io = bch2_write_endio;
+ bio->bi_private = &op->cl;
+ bio->bi_opf |= REQ_OP_WRITE;
+ closure_get(&op->cl);
+ bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
+ op->insert_keys.top, true);
+
+ bch2_keylist_push(&op->insert_keys);
+ if (op->flags & BCH_WRITE_DONE)
+ break;
+ bch2_btree_iter_advance(&iter);
+ }
+out:
+ bch2_trans_iter_exit(&trans, &iter);
+err:
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+ goto retry;
+
+ if (ret) {
+ bch_err_inum_offset_ratelimited(c,
+ op->pos.inode,
+ op->pos.offset << 9,
+ "%s: btree lookup error %s",
+ __func__, bch2_err_str(ret));
+ op->error = ret;
+ op->flags |= BCH_WRITE_DONE;
+ }
+
+ bch2_trans_exit(&trans);
+
+ /* fallback to cow write path? */
+ if (!(op->flags & BCH_WRITE_DONE)) {
+ closure_sync(&op->cl);
+ __bch2_nocow_write_done(op);
+ op->insert_keys.top = op->insert_keys.keys;
+ } else if (op->flags & BCH_WRITE_SYNC) {
+ closure_sync(&op->cl);
+ bch2_nocow_write_done(&op->cl);
+ } else {
+ /*
+ * XXX
+ * needs to run out of process context because ei_quota_lock is
+ * a mutex
+ */
+ continue_at(&op->cl, bch2_nocow_write_done, index_update_wq(op));
+ }
+ return;
+err_get_ioref:
+ bkey_for_each_ptr(ptrs, ptr2) {
+ if (ptr2 == ptr)
+ break;
+
+ percpu_ref_put(&bch_dev_bkey_exists(c, ptr2->dev)->io_ref);
+ }
+
+ /* Fall back to COW path: */
+ goto out;
+err_bucket_stale:
+ while (--i >= 0)
+ bch2_bucket_nocow_unlock(&c->nocow_locks,
+ buckets[i].b,
+ BUCKET_NOCOW_LOCK_UPDATE);
+
+ bkey_for_each_ptr(ptrs, ptr2)
+ percpu_ref_put(&bch_dev_bkey_exists(c, ptr2->dev)->io_ref);
+
+ /* We can retry this: */
+ ret = BCH_ERR_transaction_restart;
+ goto out;
+}
+
static void __bch2_write(struct bch_write_op *op)
{
struct bch_fs *c = op->c;
@@ -1230,6 +1645,12 @@ static void __bch2_write(struct bch_write_op *op)
int ret;
nofs_flags = memalloc_nofs_save();
+
+ if (unlikely(op->opts.nocow)) {
+ bch2_nocow_write(op);
+ if (op->flags & BCH_WRITE_DONE)
+ goto out_nofs_restore;
+ }
again:
memset(&op->failed, 0, sizeof(op->failed));
op->btree_update_ready = false;
@@ -1310,7 +1731,7 @@ err:
key_to_write_offset);
bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
- key_to_write);
+ key_to_write, false);
} while (ret);
/*
@@ -1332,7 +1753,7 @@ err:
} else {
continue_at(&op->cl, bch2_write_index, NULL);
}
-
+out_nofs_restore:
memalloc_nofs_restore(nofs_flags);
}
@@ -2563,6 +2984,11 @@ void bch2_fs_io_exit(struct bch_fs *c)
int bch2_fs_io_init(struct bch_fs *c)
{
+ unsigned i;
+
+ for (i = 0; i < ARRAY_SIZE(c->nocow_locks.l); i++)
+ two_state_lock_init(&c->nocow_locks.l[i]);
+
if (bioset_init(&c->bio_read, 1, offsetof(struct bch_read_bio, bio),
BIOSET_NEED_BVECS) ||
bioset_init(&c->bio_read_split, 1, offsetof(struct bch_read_bio, bio),
diff --git a/fs/bcachefs/io.h b/fs/bcachefs/io.h
index aafe1bf993bb..77a4a1cef71c 100644
--- a/fs/bcachefs/io.h
+++ b/fs/bcachefs/io.h
@@ -22,7 +22,7 @@ static inline void bch2_latency_acct(struct bch_dev *ca, u64 submit_time, int rw
#endif
void bch2_submit_wbio_replicas(struct bch_write_bio *, struct bch_fs *,
- enum bch_data_type, const struct bkey_i *);
+ enum bch_data_type, const struct bkey_i *, bool);
#define BLK_STS_REMOVED ((__force blk_status_t)128)
@@ -43,6 +43,7 @@ enum bch_write_flags {
__BCH_WRITE_IN_WORKER,
__BCH_WRITE_DONE,
__BCH_WRITE_IO_ERROR,
+ __BCH_WRITE_CONVERT_UNWRITTEN,
};
#define BCH_WRITE_ALLOC_NOWAIT (1U << __BCH_WRITE_ALLOC_NOWAIT)
@@ -61,6 +62,7 @@ enum bch_write_flags {
#define BCH_WRITE_IN_WORKER (1U << __BCH_WRITE_IN_WORKER)
#define BCH_WRITE_DONE (1U << __BCH_WRITE_DONE)
#define BCH_WRITE_IO_ERROR (1U << __BCH_WRITE_IO_ERROR)
+#define BCH_WRITE_CONVERT_UNWRITTEN (1U << __BCH_WRITE_CONVERT_UNWRITTEN)
static inline struct workqueue_struct *index_update_wq(struct bch_write_op *op)
{
@@ -90,7 +92,7 @@ static inline void bch2_write_op_init(struct bch_write_op *op, struct bch_fs *c,
op->flags = 0;
op->written = 0;
op->error = 0;
- op->csum_type = bch2_data_checksum_type(c, opts.data_checksum);
+ op->csum_type = bch2_data_checksum_type(c, opts);
op->compression_type = bch2_compression_opt_to_type[opts.compression];
op->nr_replicas = 0;
op->nr_replicas_required = c->opts.data_replicas_required;
@@ -107,6 +109,7 @@ static inline void bch2_write_op_init(struct bch_write_op *op, struct bch_fs *c,
op->res = (struct disk_reservation) { 0 };
op->new_i_size = U64_MAX;
op->i_sectors_delta = 0;
+ op->devs_need_flush = NULL;
}
void bch2_write(struct closure *);
diff --git a/fs/bcachefs/io_types.h b/fs/bcachefs/io_types.h
index 8e83ce5bc805..200af9e3e6b0 100644
--- a/fs/bcachefs/io_types.h
+++ b/fs/bcachefs/io_types.h
@@ -97,6 +97,7 @@ struct bch_write_bio {
bounce:1,
put_bio:1,
have_ioref:1,
+ nocow:1,
used_mempool:1,
first_btree_write:1;
);
@@ -151,6 +152,12 @@ struct bch_write_op {
struct keylist insert_keys;
u64 inline_keys[BKEY_EXTENT_U64s_MAX * 2];
+ /*
+ * Bitmask of devices that have had nocow writes issued to them since
+ * last flush:
+ */
+ struct bch_devs_mask *devs_need_flush;
+
/* Must be last: */
struct bch_write_bio wbio;
};
diff --git a/fs/bcachefs/move.c b/fs/bcachefs/move.c
index 52f126a0bb73..9e453b8495e8 100644
--- a/fs/bcachefs/move.c
+++ b/fs/bcachefs/move.c
@@ -260,6 +260,12 @@ static int bch2_move_extent(struct btree_trans *trans,
if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_move))
return -BCH_ERR_erofs_no_writes;
+ /*
+ * Before memory allocations & taking nocow locks in
+ * bch2_data_update_init():
+ */
+ bch2_trans_unlock(trans);
+
/* write path might have to decompress data: */
bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
sectors = max_t(unsigned, sectors, p.crc.uncompressed_size);
@@ -506,6 +512,7 @@ static int __bch2_move_data(struct moving_context *ctxt,
*/
bch2_bkey_buf_reassemble(&sk, c, k);
k = bkey_i_to_s_c(sk.k);
+ bch2_trans_unlock(&trans);
ret2 = bch2_move_extent(&trans, &iter, ctxt, io_opts,
btree_id, k, data_opts);
diff --git a/fs/bcachefs/nocow_locking.c b/fs/bcachefs/nocow_locking.c
new file mode 100644
index 000000000000..8f06e08370a2
--- /dev/null
+++ b/fs/bcachefs/nocow_locking.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "nocow_locking.h"
+#include "util.h"
+
+void __bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *t,
+ two_state_lock_t *l, int flags)
+{
+ struct bch_fs *c = container_of(t, struct bch_fs, nocow_locks);
+ u64 start_time = local_clock();
+
+ bch2_two_state_lock(l, flags & BUCKET_NOCOW_LOCK_UPDATE);
+ bch2_time_stats_update(&c->times[BCH_TIME_nocow_lock_contended], start_time);
+}
diff --git a/fs/bcachefs/nocow_locking.h b/fs/bcachefs/nocow_locking.h
new file mode 100644
index 000000000000..2a7a9f44e88e
--- /dev/null
+++ b/fs/bcachefs/nocow_locking.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_NOCOW_LOCKING_H
+#define _BCACHEFS_NOCOW_LOCKING_H
+
+#include "bcachefs_format.h"
+#include "two_state_shared_lock.h"
+
+#include <linux/hash.h>
+
+#define BUCKET_NOCOW_LOCKS_BITS 10
+#define BUCKET_NOCOW_LOCKS (1U << BUCKET_NOCOW_LOCKS_BITS)
+
+struct bucket_nocow_lock_table {
+ two_state_lock_t l[BUCKET_NOCOW_LOCKS];
+};
+
+#define BUCKET_NOCOW_LOCK_UPDATE (1 << 0)
+
+static inline two_state_lock_t *bucket_nocow_lock(struct bucket_nocow_lock_table *t,
+ struct bpos bucket)
+{
+ u64 dev_bucket = bucket.inode << 56 | bucket.offset;
+ unsigned h = hash_64(dev_bucket, BUCKET_NOCOW_LOCKS_BITS);
+
+ return t->l + (h & (BUCKET_NOCOW_LOCKS - 1));
+}
+
+static inline bool bch2_bucket_nocow_is_locked(struct bucket_nocow_lock_table *t,
+ struct bpos bucket)
+{
+ two_state_lock_t *l = bucket_nocow_lock(t, bucket);
+
+ return atomic_long_read(&l->v) != 0;
+}
+
+static inline void bch2_bucket_nocow_unlock(struct bucket_nocow_lock_table *t,
+ struct bpos bucket, int flags)
+{
+ two_state_lock_t *l = bucket_nocow_lock(t, bucket);
+
+ bch2_two_state_unlock(l, flags & BUCKET_NOCOW_LOCK_UPDATE);
+}
+
+void __bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *, two_state_lock_t *, int);
+
+static inline void bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *t,
+ struct bpos bucket, int flags)
+{
+ two_state_lock_t *l = bucket_nocow_lock(t, bucket);
+
+ if (!bch2_two_state_trylock(l, flags & BUCKET_NOCOW_LOCK_UPDATE))
+ __bch2_bucket_nocow_lock(t, l, flags);
+}
+
+#endif /* _BCACHEFS_NOCOW_LOCKING_H */
diff --git a/fs/bcachefs/opts.h b/fs/bcachefs/opts.h
index 85927b306014..ef1b8a03f149 100644
--- a/fs/bcachefs/opts.h
+++ b/fs/bcachefs/opts.h
@@ -392,6 +392,13 @@ enum opt_type {
OPT_BOOL(), \
BCH2_NO_SB_OPT, false, \
NULL, NULL) \
+ x(nocow, u8, \
+ OPT_FS|OPT_FORMAT|OPT_MOUNT|OPT_RUNTIME|OPT_INODE, \
+ OPT_BOOL(), \
+ BCH_SB_NOCOW, false, \
+ NULL, "Nocow mode: Writes will be done in place when possible.\n"\
+ "Snapshots and reflink will still caused writes to be COW\n"\
+ "Implicitly disables data checksumming, compression and encryption")\
x(no_data_io, u8, \
OPT_MOUNT, \
OPT_BOOL(), \
diff --git a/fs/bcachefs/super.h b/fs/bcachefs/super.h
index 5e6fbbfd2d43..36bcb9ec2b3a 100644
--- a/fs/bcachefs/super.h
+++ b/fs/bcachefs/super.h
@@ -88,9 +88,10 @@ static inline void bch2_dev_list_drop_dev(struct bch_devs_list *devs,
static inline void bch2_dev_list_add_dev(struct bch_devs_list *devs,
unsigned dev)
{
- BUG_ON(bch2_dev_list_has_dev(*devs, dev));
- BUG_ON(devs->nr >= ARRAY_SIZE(devs->devs));
- devs->devs[devs->nr++] = dev;
+ if (!bch2_dev_list_has_dev(*devs, dev)) {
+ BUG_ON(devs->nr >= ARRAY_SIZE(devs->devs));
+ devs->devs[devs->nr++] = dev;
+ }
}
static inline struct bch_devs_list bch2_dev_list_single(unsigned dev)
diff --git a/fs/bcachefs/trace.h b/fs/bcachefs/trace.h
index fabee8302afa..24dd2defe7c7 100644
--- a/fs/bcachefs/trace.h
+++ b/fs/bcachefs/trace.h
@@ -543,6 +543,7 @@ DECLARE_EVENT_CLASS(bucket_alloc,
__field(u64, need_journal_commit )
__field(u64, nouse )
__field(bool, nonblocking )
+ __field(u64, nocow )
__array(char, err, 32 )
),
@@ -560,10 +561,11 @@ DECLARE_EVENT_CLASS(bucket_alloc,
__entry->need_journal_commit = s->skipped_need_journal_commit;
__entry->nouse = s->skipped_nouse;
__entry->nonblocking = nonblocking;
+ __entry->nocow = s->skipped_nocow;
strscpy(__entry->err, err, sizeof(__entry->err));
),
- TP_printk("%d,%d reserve %s user %u bucket %llu free %llu avail %llu copygc_wait %llu/%lli seen %llu open %llu need_journal_commit %llu nouse %llu nonblocking %u err %s",
+ TP_printk("%d,%d reserve %s user %u bucket %llu free %llu avail %llu copygc_wait %llu/%lli seen %llu open %llu need_journal_commit %llu nouse %llu nocow %llu nonblocking %u err %s",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->reserve,
__entry->user,
@@ -576,6 +578,7 @@ DECLARE_EVENT_CLASS(bucket_alloc,
__entry->open,
__entry->need_journal_commit,
__entry->nouse,
+ __entry->nocow,
__entry->nonblocking,
__entry->err)
);