[PATCH v2 03/12] btrfs: make can_nocow_extent nowait compatible

Stefan Roesch
2022-09-08T00:26:48Z

From: Josef Bacik <josef@toxicpanda.com>

If we have NOWAIT specified on our IOCB and we're writing into a
PREALLOC or NOCOW extent then we need to be able to tell
can_nocow_extent that we don't want to wait on any locks or metadata IO.
Fix can_nocow_extent to allow for NOWAIT.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Stefan Roesch <shr@fb.com>
---
fs/btrfs/ctree.h | 5 +++--
fs/btrfs/extent-tree.c | 5 +++++
fs/btrfs/file-item.c | 4 +++-
fs/btrfs/file.c | 2 +-
fs/btrfs/inode.c | 16 ++++++++++------
fs/btrfs/relocation.c | 2 +-
fs/btrfs/scrub.c | 4 ++--
fs/btrfs/tree-log.c | 6 +++---
8 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d6d05450198d..536bbc8551fc 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3276,7 +3276,8 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
u64 offset, bool one_ordered);
int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
- struct list_head *list, int search_commit);
+ struct list_head *list, int search_commit,
+ bool nowait);
void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
const struct btrfs_path *path,
struct btrfs_file_extent_item *fi,
@@ -3306,7 +3307,7 @@ struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
u64 start, u64 len);
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
- u64 *ram_bytes, bool strict);
+ u64 *ram_bytes, bool nowait, bool strict);

void __btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 6914cd8024ba..583ddae3c270 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2220,6 +2220,11 @@ static noinline int check_delayed_ref(struct btrfs_root *root,
}

if (!mutex_trylock(&head->mutex)) {
+ if (path->nowait) {
+ spin_unlock(&delayed_refs->lock);
+ return -EAGAIN;
+ }
+
refcount_inc(&head->refs);
spin_unlock(&delayed_refs->lock);

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index c828f971a346..fcc6ce861409 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -503,7 +503,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
}

int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
- struct list_head *list, int search_commit)
+ struct list_head *list, int search_commit,
+ bool nowait)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
@@ -525,6 +526,7 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
if (!path)
return -ENOMEM;

+ path->nowait = nowait;
if (search_commit) {
path->skip_locking = 1;
path->reada = READA_FORWARD;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 5a3f6e0d9688..f4aa198f0f87 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1502,7 +1502,7 @@ int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,

btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, NULL);
ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
- NULL, NULL, NULL, false);
+ NULL, NULL, NULL, false, false);
if (ret <= 0) {
ret = 0;
btrfs_drew_write_unlock(&root->snapshot_lock);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ad250892028d..8ad3bea26652 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1667,7 +1667,7 @@ static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
}

static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
- u64 bytenr, u64 num_bytes)
+ u64 bytenr, u64 num_bytes, bool nowait)
{
struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bytenr);
struct btrfs_ordered_sum *sums;
@@ -1675,7 +1675,8 @@ static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
LIST_HEAD(list);

ret = btrfs_lookup_csums_range(csum_root, bytenr,
- bytenr + num_bytes - 1, &list, 0);
+ bytenr + num_bytes - 1, &list, 0,
+ nowait);
if (ret == 0 && list_empty(&list))
return 0;

@@ -1801,6 +1802,7 @@ static int can_nocow_file_extent(struct btrfs_path *path,
u8 extent_type;
int can_nocow = 0;
int ret = 0;
+ bool nowait = path->nowait;

fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
@@ -1877,7 +1879,8 @@ static int can_nocow_file_extent(struct btrfs_path *path,
* Force COW if csums exist in the range. This ensures that csums for a
* given extent are either valid or do not exist.
*/
- ret = csum_exist_in_range(root->fs_info, args->disk_bytenr, args->num_bytes);
+ ret = csum_exist_in_range(root->fs_info, args->disk_bytenr, args->num_bytes,
+ nowait);
WARN_ON_ONCE(ret > 0 && is_freespace_inode);
if (ret != 0)
goto out;
@@ -7293,7 +7296,7 @@ static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
- u64 *ram_bytes, bool strict)
+ u64 *ram_bytes, bool nowait, bool strict)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct can_nocow_file_extent_args nocow_args = { 0 };
@@ -7309,6 +7312,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
+ path->nowait = nowait;

ret = btrfs_lookup_file_extent(NULL, root, path,
btrfs_ino(BTRFS_I(inode)), offset, 0);
@@ -7578,7 +7582,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
block_start = em->block_start + (start - em->start);

if (can_nocow_extent(inode, start, &len, &orig_start,
- &orig_block_len, &ram_bytes, false) == 1) {
+ &orig_block_len, &ram_bytes, false, false) == 1) {
bg = btrfs_inc_nocow_writers(fs_info, block_start);
if (bg)
can_nocow = true;
@@ -11243,7 +11247,7 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
free_extent_map(em);
em = NULL;

- ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, true);
+ ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, false, true);
if (ret < 0) {
goto out;
} else if (ret) {
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 45c02aba2492..dfc3f6c04b13 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4339,7 +4339,7 @@ int btrfs_reloc_clone_csums(struct btrfs_inode *inode, u64 file_pos, u64 len)
disk_bytenr = file_pos + inode->index_cnt;
csum_root = btrfs_csum_root(fs_info, disk_bytenr);
ret = btrfs_lookup_csums_range(csum_root, disk_bytenr,
- disk_bytenr + len - 1, &list, 0);
+ disk_bytenr + len - 1, &list, 0, false);
if (ret)
goto out;

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 3afe5fa50a63..1cb3eed8b917 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3077,7 +3077,7 @@ static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,

ret = btrfs_lookup_csums_range(csum_root, extent_start,
extent_start + extent_size - 1,
- &sctx->csum_list, 1);
+ &sctx->csum_list, 1, false);
if (ret) {
scrub_parity_mark_sectors_error(sparity, extent_start,
extent_size);
@@ -3303,7 +3303,7 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
if (extent_flags & BTRFS_EXTENT_FLAG_DATA) {
ret = btrfs_lookup_csums_range(csum_root, cur_logical,
cur_logical + scrub_len - 1,
- &sctx->csum_list, 1);
+ &sctx->csum_list, 1, false);
if (ret)
break;
}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 9205c4a5ca81..8af30dab2a17 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -801,7 +801,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,

ret = btrfs_lookup_csums_range(root->log_root,
csum_start, csum_end - 1,
- &ordered_sums, 0);
+ &ordered_sums, 0, false);
if (ret)
goto out;
/*
@@ -4513,7 +4513,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
disk_bytenr += extent_offset;
ret = btrfs_lookup_csums_range(csum_root, disk_bytenr,
disk_bytenr + extent_num_bytes - 1,
- &ordered_sums, 0);
+ &ordered_sums, 0, false);
if (ret)
goto out;

@@ -4709,7 +4709,7 @@ static int log_extent_csums(struct btrfs_trans_handle *trans,
ret = btrfs_lookup_csums_range(csum_root,
em->block_start + csum_offset,
em->block_start + csum_offset +
- csum_len - 1, &ordered_sums, 0);
+ csum_len - 1, &ordered_sums, 0, false);
if (ret)
return ret;

--
2.30.2