[PATCH RFC v2 for-6.8/block 09/18] btrfs: use bdev apis

Yu Kuai
2023-12-11T14:07:35Z

On the one hand covert to use folio while reading bdev inode, on the
other hand prevent to access bd_inode directly.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
fs/btrfs/disk-io.c | 71 +++++++++++++++++++++-------------------------
fs/btrfs/volumes.c | 17 ++++++-----
fs/btrfs/zoned.c | 15 +++++-----
3 files changed, 48 insertions(+), 55 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 401ea09ae4b8..c373806dc793 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3620,28 +3620,24 @@ ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
static void btrfs_end_super_write(struct bio *bio)
{
struct btrfs_device *device = bio->bi_private;
- struct bio_vec *bvec;
- struct bvec_iter_all iter_all;
- struct page *page;
-
- bio_for_each_segment_all(bvec, bio, iter_all) {
- page = bvec->bv_page;
+ struct folio_iter fi;

+ bio_for_each_folio_all(fi, bio) {
if (bio->bi_status) {
btrfs_warn_rl_in_rcu(device->fs_info,
"lost page write due to IO error on %s (%d)",
btrfs_dev_name(device),
blk_status_to_errno(bio->bi_status));
- ClearPageUptodate(page);
- SetPageError(page);
+ folio_clear_uptodate(fi.folio);
+ folio_set_error(fi.folio);
btrfs_dev_stat_inc_and_print(device,
BTRFS_DEV_STAT_WRITE_ERRS);
} else {
- SetPageUptodate(page);
+ folio_mark_uptodate(fi.folio);
}

- put_page(page);
- unlock_page(page);
+ folio_put(fi.folio);
+ folio_unlock(fi.folio);
}

bio_put(bio);
@@ -3651,9 +3647,9 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
int copy_num, bool drop_cache)
{
struct btrfs_super_block *super;
- struct page *page;
+ struct folio *folio;
u64 bytenr, bytenr_orig;
- struct address_space *mapping = bdev->bd_inode->i_mapping;
+ unsigned int nofs_flag;
int ret;

bytenr_orig = btrfs_sb_offset(copy_num);
@@ -3674,16 +3670,17 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
* Drop the page of the primary superblock, so later read will
* always read from the device.
*/
- invalidate_inode_pages2_range(mapping,
- bytenr >> PAGE_SHIFT,
+ invalidate_bdev_range(bdev, bytenr >> PAGE_SHIFT,
(bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT);
}

- page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
- if (IS_ERR(page))
- return ERR_CAST(page);
+ nofs_flag = memalloc_nofs_save();
+ folio = bdev_read_folio(bdev, bytenr);
+ memalloc_nofs_restore(nofs_flag);
+ if (IS_ERR(folio))
+ return ERR_CAST(folio);

- super = page_address(page);
+ super = folio_address(folio);
if (btrfs_super_magic(super) != BTRFS_MAGIC) {
btrfs_release_disk_super(super);
return ERR_PTR(-ENODATA);
@@ -3740,7 +3737,6 @@ static int write_dev_supers(struct btrfs_device *device,
struct btrfs_super_block *sb, int max_mirrors)
{
struct btrfs_fs_info *fs_info = device->fs_info;
- struct address_space *mapping = device->bdev->bd_inode->i_mapping;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
int i;
int errors = 0;
@@ -3753,7 +3749,7 @@ static int write_dev_supers(struct btrfs_device *device,
shash->tfm = fs_info->csum_shash;

for (i = 0; i < max_mirrors; i++) {
- struct page *page;
+ struct folio *folio;
struct bio *bio;
struct btrfs_super_block *disk_super;

@@ -3778,9 +3774,10 @@ static int write_dev_supers(struct btrfs_device *device,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
sb->csum);

- page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
- GFP_NOFS);
- if (!page) {
+ folio = __bdev_get_folio(device->bdev, bytenr,
+ FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
+ GFP_NOFS);
+ if (IS_ERR(folio)) {
btrfs_err(device->fs_info,
"couldn't get super block page for bytenr %llu",
bytenr);
@@ -3789,9 +3786,9 @@ static int write_dev_supers(struct btrfs_device *device,
}

/* Bump the refcount for wait_dev_supers() */
- get_page(page);
+ folio_get(folio);

- disk_super = page_address(page);
+ disk_super = folio_address(folio);
memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);

/*
@@ -3805,8 +3802,8 @@ static int write_dev_supers(struct btrfs_device *device,
bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
bio->bi_private = device;
bio->bi_end_io = btrfs_end_super_write;
- __bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
- offset_in_page(bytenr));
+ bio_add_folio_nofail(bio, folio, BTRFS_SUPER_INFO_SIZE,
+ offset_in_folio(folio, bytenr));

/*
* We FUA only the first super block. The others we allow to
@@ -3842,7 +3839,7 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
max_mirrors = BTRFS_SUPER_MIRROR_MAX;

for (i = 0; i < max_mirrors; i++) {
- struct page *page;
+ struct folio *folio;

ret = btrfs_sb_log_location(device, i, READ, &bytenr);
if (ret == -ENOENT) {
@@ -3857,27 +3854,23 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
device->commit_total_bytes)
break;

- page = find_get_page(device->bdev->bd_inode->i_mapping,
- bytenr >> PAGE_SHIFT);
- if (!page) {
+ folio = __bdev_get_folio(device->bdev, bytenr, 0, 0);
+ if (!IS_ERR(folio)) {
errors++;
if (i == 0)
primary_failed = true;
continue;
}
/* Page is submitted locked and unlocked once the IO completes */
- wait_on_page_locked(page);
- if (PageError(page)) {
+ folio_wait_locked(folio);
+ if (folio_test_error(folio)) {
errors++;
if (i == 0)
primary_failed = true;
}

- /* Drop our reference */
- put_page(page);
-
- /* Drop the reference from the writing run */
- put_page(page);
+ /* Drop our reference and the reference from the writing run */
+ folio_put_refs(folio, 2);
}

/* log error, force error return */
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c6f16625af51..b3538777683c 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1230,16 +1230,16 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,

void btrfs_release_disk_super(struct btrfs_super_block *super)
{
- struct page *page = virt_to_page(super);
+ struct folio *folio = virt_to_folio(super);

- put_page(page);
+ folio_put(folio);
}

static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
u64 bytenr, u64 bytenr_orig)
{
struct btrfs_super_block *disk_super;
- struct page *page;
+ struct folio *folio;
void *p;
pgoff_t index;

@@ -1257,15 +1257,14 @@ static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev
return ERR_PTR(-EINVAL);

/* pull in the page with our super */
- page = read_cache_page_gfp(bdev->bd_inode->i_mapping, index, GFP_KERNEL);
+ folio = bdev_read_folio(bdev, index);
+ if (IS_ERR(folio))
+ return ERR_CAST(folio);

- if (IS_ERR(page))
- return ERR_CAST(page);
-
- p = page_address(page);
+ p = folio_address(folio);

/* align our pointer to the offset of the super block */
- disk_super = p + offset_in_page(bytenr);
+ disk_super = p + offset_in_folio(folio, bytenr);

if (btrfs_super_bytenr(disk_super) != bytenr_orig ||
btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 188378ca19c7..aea0a433b3e5 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -120,8 +120,6 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
return -ENOENT;
} else if (full[0] && full[1]) {
/* Compare two super blocks */
- struct address_space *mapping = bdev->bd_inode->i_mapping;
- struct page *page[BTRFS_NR_SB_LOG_ZONES];
struct btrfs_super_block *super[BTRFS_NR_SB_LOG_ZONES];
int i;

@@ -129,15 +127,18 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
u64 zone_end = (zones[i].start + zones[i].capacity) << SECTOR_SHIFT;
u64 bytenr = ALIGN_DOWN(zone_end, BTRFS_SUPER_INFO_SIZE) -
BTRFS_SUPER_INFO_SIZE;
+ struct folio *folio;
+ unsigned int nofs_flag;

- page[i] = read_cache_page_gfp(mapping,
- bytenr >> PAGE_SHIFT, GFP_NOFS);
- if (IS_ERR(page[i])) {
+ nofs_flag = memalloc_nofs_save();
+ folio = bdev_read_folio(bdev, bytenr);
+ memalloc_nofs_restore(nofs_flag);
+ if (IS_ERR(folio)) {
if (i == 1)
btrfs_release_disk_super(super[0]);
- return PTR_ERR(page[i]);
+ return PTR_ERR(folio);
}
- super[i] = page_address(page[i]);
+ super[i] = folio_address(folio);
}

if (btrfs_super_generation(super[0]) >
--
2.39.2