[PATCH v1 03/10] btrfs: add the ability to use NO_FLUSH for data reservations

Stefan Roesch
2022-09-01T22:59:26Z

From: Josef Bacik <josef@toxicpanda.com>

In order to accommodate NOWAIT IOCB's we need to be able to do NO_FLUSH
data reservations, so plumb this through the delalloc reservation
system.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Stefan Roesch <shr@fb.com>
---
fs/btrfs/block-group.c | 2 +-
fs/btrfs/delalloc-space.c | 13 ++++++++++---
fs/btrfs/delalloc-space.h | 3 ++-
fs/btrfs/file.c | 2 +-
fs/btrfs/inode.c | 4 ++--
fs/btrfs/space-info.c | 3 ++-
6 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index e0375ba9d0fe..9df51245ba93 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2869,7 +2869,7 @@ static int cache_save_setup(struct btrfs_block_group *block_group,
cache_size *= fs_info->sectorsize;

ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, 0,
- cache_size);
+ cache_size, false);
if (ret)
goto out_put;

diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index 1e8f17ff829e..118b2e20b2e1 100644
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -127,9 +127,11 @@ int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
}

int btrfs_check_data_free_space(struct btrfs_inode *inode,
- struct extent_changeset **reserved, u64 start, u64 len)
+ struct extent_changeset **reserved, u64 start,
+ u64 len, bool noflush)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
+ enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_DATA;
int ret;

/* align the range */
@@ -137,7 +139,12 @@ int btrfs_check_data_free_space(struct btrfs_inode *inode,
round_down(start, fs_info->sectorsize);
start = round_down(start, fs_info->sectorsize);

- ret = btrfs_alloc_data_chunk_ondemand(inode, len);
+ if (noflush)
+ flush = BTRFS_RESERVE_NO_FLUSH;
+ else if (btrfs_is_free_space_inode(inode))
+ flush = BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE;
+
+ ret = btrfs_reserve_data_bytes(fs_info, len, flush);
if (ret < 0)
return ret;

@@ -454,7 +461,7 @@ int btrfs_delalloc_reserve_space(struct btrfs_inode *inode,
{
int ret;

- ret = btrfs_check_data_free_space(inode, reserved, start, len);
+ ret = btrfs_check_data_free_space(inode, reserved, start, len, false);
if (ret < 0)
return ret;
ret = btrfs_delalloc_reserve_metadata(inode, len, len, false);
diff --git a/fs/btrfs/delalloc-space.h b/fs/btrfs/delalloc-space.h
index 28bf5c3ef430..e07d46043455 100644
--- a/fs/btrfs/delalloc-space.h
+++ b/fs/btrfs/delalloc-space.h
@@ -7,7 +7,8 @@ struct extent_changeset;

int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes);
int btrfs_check_data_free_space(struct btrfs_inode *inode,
- struct extent_changeset **reserved, u64 start, u64 len);
+ struct extent_changeset **reserved, u64 start, u64 len,
+ bool noflush);
void btrfs_free_reserved_data_space(struct btrfs_inode *inode,
struct extent_changeset *reserved, u64 start, u64 len);
void btrfs_delalloc_release_space(struct btrfs_inode *inode,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f4aa198f0f87..0f257205c63d 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1664,7 +1664,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
extent_changeset_release(data_reserved);
ret = btrfs_check_data_free_space(BTRFS_I(inode),
&data_reserved, pos,
- write_bytes);
+ write_bytes, false);
if (ret < 0) {
/*
* If we don't have to COW at the offset, reserve
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8ad3bea26652..36e755f73764 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4882,7 +4882,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
block_end = block_start + blocksize - 1;

ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,
- blocksize);
+ blocksize, false);
if (ret < 0) {
if (btrfs_check_nocow_lock(inode, block_start, &write_bytes) > 0) {
/* For nocow case, no need to reserve data space */
@@ -7767,7 +7767,7 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
if (write && !(flags & IOMAP_NOWAIT)) {
ret = btrfs_check_data_free_space(BTRFS_I(inode),
&dio_data->data_reserved,
- start, data_alloc_len);
+ start, data_alloc_len, false);
if (!ret)
dio_data->data_space_reserved = true;
else if (ret && !(BTRFS_I(inode)->flags &
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index d0cbeb7ae81c..0738e1efed79 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -1737,7 +1737,8 @@ int btrfs_reserve_data_bytes(struct btrfs_fs_info *fs_info, u64 bytes,
int ret;

ASSERT(flush == BTRFS_RESERVE_FLUSH_DATA ||
- flush == BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE);
+ flush == BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE ||
+ flush == BTRFS_RESERVE_NO_FLUSH);
ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_DATA);

ret = __reserve_bytes(fs_info, data_sinfo, bytes, flush);
--
2.30.2