btrfs-progs: update comments for device helpers

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2021-04-29 18:56:00 +02:00
parent 51c0ece9f6
commit a2dbbcfe88
2 changed files with 25 additions and 2 deletions

View File

@ -89,7 +89,10 @@ int device_zero_blocks(int fd, off_t start, size_t len)
#define ZERO_DEV_BYTES SZ_2M
/* don't write outside the device by clamping the region to the device size */
/*
* Zero blocks in the range from start but not after the given device size.
* (On SPARC the disk labels are preserved too.)
*/
static int zero_dev_clamped(int fd, struct btrfs_zoned_device_info *zinfo,
off_t start, ssize_t len, u64 dev_size)
{
@ -110,6 +113,9 @@ static int zero_dev_clamped(int fd, struct btrfs_zoned_device_info *zinfo,
return device_zero_blocks(fd, start, end - start);
}
/*
* Find all magic signatures known to blkid and remove them
*/
static int btrfs_wipe_existing_sb(int fd, struct btrfs_zoned_device_info *zinfo)
{
const char *off = NULL;
@ -173,6 +179,13 @@ out:
return ret;
}
/*
* Prepare a device before it's added to the filesystem. Optionally:
* - remove old superblocks
* - discard
* - reset zones
* - delete end of the device
*/
int btrfs_prepare_device(int fd, const char *file, u64 *block_count_ret,
u64 max_block_count, unsigned opflags)
{

View File

@ -20,18 +20,28 @@
#include "kerncompat.h"
#include "sys/stat.h"
/*
* Options for btrfs_prepare_device
*/
#define PREP_DEVICE_ZERO_END (1U << 0)
#define PREP_DEVICE_DISCARD (1U << 1)
#define PREP_DEVICE_VERBOSE (1U << 2)
#define PREP_DEVICE_ZONED (1U << 3)
/*
* Generic block device helpers
*/
int device_discard_blocks(int fd, u64 start, u64 len);
int device_zero_blocks(int fd, off_t start, size_t len);
u64 device_get_partition_size(const char *dev);
u64 disk_size(const char *path);
int device_get_queue_param(const char *file, const char *param, char *buf, size_t len);
/*
* Updates to devices with btrfs-specific changs
*/
u64 btrfs_device_size(int fd, struct stat *st);
int btrfs_prepare_device(int fd, const char *file, u64 *block_count_ret,
u64 max_block_count, unsigned opflags);
int device_get_queue_param(const char *file, const char *param, char *buf, size_t len);
#endif