[PATCH 25/29] dax: return the partition offset from fs_dax_get_by_bdev

Christoph Hellwig
2021-11-09T08:34:27Z

Prepare from removing the block_device from the DAX I/O path by returning
the partition offset from fs_dax_get_by_bdev so that the file systems
have it at hand for use during I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/dax/super.c | 9 ++++++---
drivers/md/dm.c | 4 ++--
fs/erofs/internal.h | 2 ++
fs/erofs/super.c | 4 ++--
fs/ext2/ext2.h | 1 +
fs/ext2/super.c | 2 +-
fs/ext4/ext4.h | 1 +
fs/ext4/super.c | 2 +-
fs/xfs/xfs_buf.c | 2 +-
fs/xfs/xfs_buf.h | 1 +
include/linux/dax.h | 6 ++++--
11 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index c0910687fbcb2..cc32dcf71c116 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -70,17 +70,20 @@ EXPORT_SYMBOL_GPL(dax_remove_host);
/**
* dax_get_by_host() - temporary lookup mechanism for filesystem-dax
* @bdev: block device to find a dax_device for
+ * @start_off: returns the byte offset into the dax_device that @bdev starts
*/
-struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
+struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, u64 *start_off)
{
struct dax_device *dax_dev;
+ u64 part_size;
int id;

if (!blk_queue_dax(bdev->bd_disk->queue))
return NULL;

- if ((get_start_sect(bdev) * SECTOR_SIZE) % PAGE_SIZE ||
- (bdev_nr_sectors(bdev) * SECTOR_SIZE) % PAGE_SIZE) {
+ *start_off = get_start_sect(bdev) * SECTOR_SIZE;
+ part_size = bdev_nr_sectors(bdev) * SECTOR_SIZE;
+ if (*start_off % PAGE_SIZE || part_size % PAGE_SIZE) {
pr_info("%pg: error: unaligned partition for dax\n", bdev);
return NULL;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 282008afc465f..5ea6115d19bdc 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -637,7 +637,7 @@ static int open_table_device(struct table_device *td, dev_t dev,
struct mapped_device *md)
{
struct block_device *bdev;
-
+ u64 part_off;
int r;

BUG_ON(td->dm_dev.bdev);
@@ -653,7 +653,7 @@ static int open_table_device(struct table_device *td, dev_t dev,
}

td->dm_dev.bdev = bdev;
- td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev);
+ td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off);
return 0;
}

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 3265688af7f9f..c1e65346e9f15 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -51,6 +51,7 @@ struct erofs_device_info {
char *path;
struct block_device *bdev;
struct dax_device *dax_dev;
+ u64 dax_part_off;

u32 blocks;
u32 mapped_blkaddr;
@@ -109,6 +110,7 @@ struct erofs_sb_info {
#endif /* CONFIG_EROFS_FS_ZIP */
struct erofs_dev_context *devs;
struct dax_device *dax_dev;
+ u64 dax_part_off;
u64 total_blocks;
u32 primarydevice_blocks;

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 0aed886473c8d..71efce16024d9 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -312,7 +312,7 @@ static int erofs_init_devices(struct super_block *sb,
goto err_out;
}
dif->bdev = bdev;
- dif->dax_dev = fs_dax_get_by_bdev(bdev);
+ dif->dax_dev = fs_dax_get_by_bdev(bdev, &dif->dax_part_off);
dif->blocks = le32_to_cpu(dis->blocks);
dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr);
sbi->total_blocks += dif->blocks;
@@ -644,7 +644,7 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)

sb->s_fs_info = sbi;
sbi->opt = ctx->opt;
- sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
+ sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->dax_part_off);
sbi->devs = ctx->devs;
ctx->devs = NULL;

diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 3be9dd6412b78..d4f306aa5aceb 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -118,6 +118,7 @@ struct ext2_sb_info {
spinlock_t s_lock;
struct mb_cache *s_ea_block_cache;
struct dax_device *s_daxdev;
+ u64 s_dax_part_off;
};

static inline spinlock_t *
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 7e23482862e69..94f1fbd7d3ac2 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -831,7 +831,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
}
sb->s_fs_info = sbi;
sbi->s_sb_block = sb_block;
- sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev);
+ sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);

spin_lock_init(&sbi->s_lock);
ret = -EINVAL;
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3825195539d74..6f01994a1d52f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1696,6 +1696,7 @@ struct ext4_sb_info {
*/
struct percpu_rw_semaphore s_writepages_rwsem;
struct dax_device *s_daxdev;
+ u64 s_dax_part_off;
#ifdef CONFIG_EXT4_DEBUG
unsigned long s_simulate_fail;
#endif
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b60401bb1c310..5a833847c5e65 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3914,7 +3914,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
if (!sbi->s_blockgroup_lock)
goto out_free_base;

- sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev);
+ sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off);
sb->s_fs_info = sbi;
sbi->s_sb = sb;
sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 4d4553ffa7050..bbb0fbd34e649 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1945,7 +1945,7 @@ xfs_alloc_buftarg(
btp->bt_mount = mp;
btp->bt_dev = bdev->bd_dev;
btp->bt_bdev = bdev;
- btp->bt_daxdev = fs_dax_get_by_bdev(bdev);
+ btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off);

/*
* Buffer IO error rate limiting. Limit it to no more than 10 messages
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index bd7f709f0d232..edcb6254fa6a8 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -89,6 +89,7 @@ typedef struct xfs_buftarg {
dev_t bt_dev;
struct block_device *bt_bdev;
struct dax_device *bt_daxdev;
+ u64 bt_dax_part_off;
struct xfs_mount *bt_mount;
unsigned int bt_meta_sectorsize;
size_t bt_meta_sectormask;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index a5cc2f1aa840e..90f95deff504d 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -117,7 +117,8 @@ static inline void fs_put_dax(struct dax_device *dax_dev)
put_dax(dax_dev);
}

-struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
+struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev,
+ u64 *start_off);
int dax_writeback_mapping_range(struct address_space *mapping,
struct dax_device *dax_dev, struct writeback_control *wbc);

@@ -142,7 +143,8 @@ static inline void fs_put_dax(struct dax_device *dax_dev)
{
}

-static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
+static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev,
+ u64 *start_off)
{
return NULL;
}
--
2.30.2