Super-block reading in BTRFS is done using buffer_heads. Buffer_heads have
some drawbacks, like not being able to propagate errors from the lower
layers.
Change the buffer_heads to BIOs.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
---
fs/btrfs/disk-io.c | 80 +++++++++++++++++++++++++++-------------------
fs/btrfs/disk-io.h | 4 +--
fs/btrfs/volumes.c | 64 ++++++++++++++++++++++---------------
fs/btrfs/volumes.h | 2 --
4 files changed, 88 insertions(+), 62 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5ce2801f8388..50c93ffe8d03 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2635,11 +2635,11 @@ int __cold open_ctree(struct super_block *sb,
u64 features;
u16 csum_type;
struct btrfs_key location;
- struct buffer_head *bh;
struct btrfs_super_block *disk_super;
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_root *tree_root;
struct btrfs_root *chunk_root;
+ struct page *super_page;
int ret;
int err = -EINVAL;
int clear_free_space_tree = 0;
@@ -2832,39 +2832,37 @@ int __cold open_ctree(struct super_block *sb,
/*
* Read super block and check the signature bytes only
*/
- bh = btrfs_read_dev_super(fs_devices->latest_bdev);
- if (IS_ERR(bh)) {
- err = PTR_ERR(bh);
- goto fail_alloc;
+ ret = btrfs_read_dev_super(fs_devices->latest_bdev, &super_page);
+ if (ret) {
+ err = ret;
+ goto fail_page_alloc;
}
/*
* Verify the type first, if that or the the checksum value are
* corrupted, we'll find out
*/
- csum_type = btrfs_super_csum_type((struct btrfs_super_block *)bh->b_data);
+ csum_type = btrfs_super_csum_type(page_address(super_page));
if (!btrfs_supported_super_csum(csum_type)) {
btrfs_err(fs_info, "unsupported checksum algorithm: %u",
csum_type);
err = -EINVAL;
- brelse(bh);
- goto fail_alloc;
+ goto fail_page_alloc;
}
ret = btrfs_init_csum_hash(fs_info, csum_type);
if (ret) {
err = ret;
- goto fail_alloc;
+ goto fail_page_alloc;
}
/*
* We want to check superblock checksum, the type is stored inside.
* Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
*/
- if (btrfs_check_super_csum(fs_info, bh->b_data)) {
+ if (btrfs_check_super_csum(fs_info, page_address(super_page))) {
btrfs_err(fs_info, "superblock checksum mismatch");
err = -EINVAL;
- brelse(bh);
goto fail_csum;
}
@@ -2873,8 +2871,9 @@ int __cold open_ctree(struct super_block *sb,
* following bytes up to INFO_SIZE, the checksum is calculated from
* the whole block of INFO_SIZE
*/
- memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
- brelse(bh);
+ memcpy(fs_info->super_copy, page_address(super_page),
+ sizeof(*fs_info->super_copy));
+ __free_page(super_page);
disk_super = fs_info->super_copy;
@@ -3330,6 +3329,8 @@ int __cold open_ctree(struct super_block *sb,
btrfs_free_block_groups(fs_info);
fail_csum:
btrfs_free_csum_hash(fs_info);
+fail_page_alloc:
+ __free_page(super_page);
fail_alloc:
fail_iput:
btrfs_mapping_tree_free(&fs_info->mapping_tree);
@@ -3374,40 +3375,52 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
}
int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
- struct buffer_head **bh_ret)
+ struct page **super_page)
{
- struct buffer_head *bh;
struct btrfs_super_block *super;
+ struct bio_vec bio_vec;
+ struct bio bio;
+ struct page *page;
u64 bytenr;
+ gfp_t gfp_mask = mapping_gfp_constraint(bdev->bd_inode->i_mapping,
+ ~__GFP_FS) | __GFP_NOFAIL;
+ int ret;
bytenr = btrfs_sb_offset(copy_num);
if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
return -EINVAL;
- bh = __bread(bdev, bytenr / BTRFS_BDEV_BLOCKSIZE, BTRFS_SUPER_INFO_SIZE);
+ page = alloc_page(gfp_mask);
+ if (!page)
+ return -ENOMEM;
+
+ bio_init(&bio, &bio_vec, 1);
+ bio.bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
+ bio_set_dev(&bio, bdev);
+ bio_set_op_attrs(&bio, REQ_OP_READ, 0);
+ bio_add_page(&bio, page, BTRFS_SUPER_INFO_SIZE, 0);
+
+ ret = submit_bio_wait(&bio);
/*
* If we fail to read from the underlying devices, as of now
* the best option we have is to mark it EIO.
*/
- if (!bh)
+ if (ret)
return -EIO;
- super = (struct btrfs_super_block *)bh->b_data;
+ super = page_address(page);
if (btrfs_super_bytenr(super) != bytenr ||
- btrfs_super_magic(super) != BTRFS_MAGIC) {
- brelse(bh);
+ btrfs_super_magic(super) != BTRFS_MAGIC)
return -EINVAL;
- }
- *bh_ret = bh;
+ *super_page = page;
return 0;
}
-struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
+int btrfs_read_dev_super(struct block_device *bdev, struct page **page)
{
- struct buffer_head *bh;
- struct buffer_head *latest = NULL;
+ struct page *latest = NULL;
struct btrfs_super_block *super;
int i;
u64 transid = 0;
@@ -3419,25 +3432,26 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
for (i = 0; i < 1; i++) {
- ret = btrfs_read_dev_one_super(bdev, i, &bh);
+ ret = btrfs_read_dev_one_super(bdev, i, page);
if (ret)
continue;
- super = (struct btrfs_super_block *)bh->b_data;
+ super = page_address(*page);
if (!latest || btrfs_super_generation(super) > transid) {
- brelse(latest);
- latest = bh;
+ if (latest)
+ __free_page(latest);
+ latest = *page;
transid = btrfs_super_generation(super);
} else {
- brelse(bh);
+ __free_page(*page);
}
}
- if (!latest)
- return ERR_PTR(ret);
+ if (ret)
+ return ret;
- return latest;
+ return 0;
}
/*
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 8c2d6cf1ce59..e04b233c436a 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -54,9 +54,9 @@ int __cold open_ctree(struct super_block *sb,
char *options);
void __cold close_ctree(struct btrfs_fs_info *fs_info);
int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
-struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
+int btrfs_read_dev_super(struct block_device *bdev, struct page **super_page);
int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
- struct buffer_head **bh_ret);
+ struct page **super_page);
int btrfs_commit_super(struct btrfs_fs_info *fs_info);
struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
struct btrfs_key *location);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3d5714bf2e32..4aded417a7d1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6,7 +6,6 @@
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/slab.h>
-#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include <linux/kthread.h>
@@ -492,7 +491,7 @@ static noinline struct btrfs_fs_devices *find_fsid(
static int
btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
int flush, struct block_device **bdev,
- struct buffer_head **bh)
+ struct page **super_page)
{
int ret;
@@ -511,9 +510,8 @@ btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
goto error;
}
invalidate_bdev(*bdev);
- *bh = btrfs_read_dev_super(*bdev);
- if (IS_ERR(*bh)) {
- ret = PTR_ERR(*bh);
+ ret = btrfs_read_dev_super(*bdev, super_page);
+ if (ret) {
blkdev_put(*bdev, flags);
goto error;
}
@@ -522,7 +520,6 @@ btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
error:
*bdev = NULL;
- *bh = NULL;
return ret;
}
@@ -603,7 +600,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
{
struct request_queue *q;
struct block_device *bdev;
- struct buffer_head *bh;
+ struct page *super_page;
struct btrfs_super_block *disk_super;
u64 devid;
int ret;
@@ -614,17 +611,17 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
return -EINVAL;
ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
- &bdev, &bh);
+ &bdev, &super_page);
if (ret)
return ret;
- disk_super = (struct btrfs_super_block *)bh->b_data;
+ disk_super = page_address(super_page);
devid = btrfs_stack_device_id(&disk_super->dev_item);
if (devid != device->devid)
- goto error_brelse;
+ goto error_free_page;
if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE))
- goto error_brelse;
+ goto error_free_page;
device->generation = btrfs_super_generation(disk_super);
@@ -633,7 +630,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
BTRFS_FEATURE_INCOMPAT_METADATA_UUID) {
pr_err(
"BTRFS: Invalid seeding and uuid-changed device detected\n");
- goto error_brelse;
+ goto error_free_page;
}
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
@@ -659,12 +656,12 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
fs_devices->rw_devices++;
list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list);
}
- brelse(bh);
+ __free_page(super_page);
return 0;
-error_brelse:
- brelse(bh);
+error_free_page:
+ __free_page(super_page);
blkdev_put(bdev, flags);
return -EINVAL;
@@ -2164,14 +2161,15 @@ static struct btrfs_device *btrfs_find_device_by_path(
u64 devid;
u8 *dev_uuid;
struct block_device *bdev;
- struct buffer_head *bh;
+ struct page *super_page;
struct btrfs_device *device;
ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
- fs_info->bdev_holder, 0, &bdev, &bh);
+ fs_info->bdev_holder, 0, &bdev,
+ &super_page);
if (ret)
return ERR_PTR(ret);
- disk_super = (struct btrfs_super_block *)bh->b_data;
+ disk_super = page_address(super_page);
devid = btrfs_stack_device_id(&disk_super->dev_item);
dev_uuid = disk_super->dev_item.uuid;
if (btrfs_fs_incompat(fs_info, METADATA_UUID))
@@ -2181,7 +2179,7 @@ static struct btrfs_device *btrfs_find_device_by_path(
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
disk_super->fsid, true);
- brelse(bh);
+ __free_page(super_page);
if (!device)
device = ERR_PTR(-ENOENT);
blkdev_put(bdev, FMODE_READ);
@@ -7270,25 +7268,41 @@ int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path)
{
- struct buffer_head *bh;
+ struct page *super_page;
+ struct bio_vec bio_vec;
+ struct bio bio;
struct btrfs_super_block *disk_super;
int copy_num;
+ int ret;
if (!bdev)
return;
+ bio_init(&bio, &bio_vec, 1);
for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX;
copy_num++) {
+ u64 bytenr;
- if (btrfs_read_dev_one_super(bdev, copy_num, &bh))
+ if (btrfs_read_dev_one_super(bdev, copy_num, &super_page))
continue;
- disk_super = (struct btrfs_super_block *)bh->b_data;
+ disk_super = page_address(super_page);
memset(&disk_super->magic, 0, sizeof(disk_super->magic));
- set_buffer_dirty(bh);
- sync_dirty_buffer(bh);
- brelse(bh);
+
+ bytenr = btrfs_sb_offset(copy_num);
+
+ bio.bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
+ bio_set_dev(&bio, bdev);
+ bio_set_op_attrs(&bio, REQ_OP_WRITE, 0);
+ bio_add_page(&bio, super_page, PAGE_SIZE, 0);
+
+ ret = submit_bio_wait(&bio);
+ WARN_ON(ret);
+
+ __free_page(super_page);
+ bio_reset(&bio);
+
}
/* Notify udev that device has changed */
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 9c7d4fe5c39a..46a65b15eb93 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -17,8 +17,6 @@ extern struct mutex uuid_mutex;
#define BTRFS_STRIPE_LEN SZ_64K
-struct buffer_head;
-
struct btrfs_io_geometry {
/* remaining bytes before crossing a stripe */
u64 len;
--
2.24.1
