ublk: add support for integrity data #447
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blk_integrity_rq() doesn't modify the struct request passed in, so allow a const pointer to be passed. Use a matching signature for the !CONFIG_BLK_DEV_INTEGRITY version. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com>
ublk_dev_support_user_copy() will be used in ublk_validate_params().
Move these functions next to ublk_{dev,queue}_is_zoned() to avoid
needing to forward-declare them.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Add a feature flag UBLK_F_INTEGRITY for a ublk server to request integrity/metadata support when creating a ublk device. The ublk server can also check for the feature flag on the created device or the result of UBLK_U_CMD_GET_FEATURES to tell if the ublk driver supports it. UBLK_F_INTEGRITY requires UBLK_F_USER_COPY, as user copy is the only data copy mode initially supported for integrity data. Add UBLK_PARAM_TYPE_INTEGRITY and struct ublk_param_integrity to struct ublk_params to specify the integrity params of a ublk device. UBLK_PARAM_TYPE_INTEGRITY requires UBLK_F_INTEGRITY and a nonzero metadata_size. The LBMD_PI_CAP_* and LBMD_PI_CSUM_* values from the linux/fs.h UAPI header are used for the flags and csum_type fields. If the UBLK_PARAM_TYPE_INTEGRITY flag is set, validate the integrity parameters and apply them to the blk_integrity limits. The struct ublk_param_integrity validations are based on the checks in blk_validate_integrity_limits(). Any invalid parameters should be rejected before being applied to struct blk_integrity. Signed-off-by: Stanley Zhang <stazhang@purestorage.com> [csander: drop redundant pi_tuple_size field, use block metadata UAPI constants, add param validation] Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Indicate to the ublk server when an incoming request has integrity data
by setting UBLK_IO_F_INTEGRITY in the ublksrv_io_desc's op_flags field.
If the ublk device doesn't support integrity, the request will never
provide integrity data. If the ublk device supports integrity, the
request may omit the integrity buffer only if metadata_size matches the
PI tuple size determined by csum_type. In this case, the ublk server
should internally generate/verify the protection information from the
data and sector offset.
Set the UBLK_IO_F_CHECK_{GUARD,REFTAG,APPTAG} flags based on the
request's BIP_CHECK_{GUARD,REFTAG,APPTAG} flags, indicating whether to
verify the guard, reference, and app tags in the protection information.
The expected reference tag (32 or 48 bits) and app tag (16 bits) are
indicated in ublksrv_io_desc's new struct ublksrv_io_integrity integrity
field. This field is unioned with the addr field to avoid changing the
size of struct ublksrv_io_desc. UBLK_F_INTEGRITY requires
UBLK_F_USER_COPY and the addr field isn't used for UBLK_F_USER_COPY, so
the two fields aren't needed simultaneously.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Factor a helper function ublk_copy_user_bvec() out of ublk_copy_user_pages(). It will be used for copying integrity data too. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
ublk_ch_read_iter() and ublk_ch_write_iter() are nearly identical except for the iter direction. Split out a helper function ublk_user_copy() to reduce the code duplication as these functions are about to get larger. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com>
ublk_check_and_get_req() has a single callsite in ublk_user_copy(). It takes a ton of arguments in order to pass local variables from ublk_user_copy() to ublk_check_and_get_req() and vice versa. And more are about to be added. Combine the functions to reduce the argument passing noise. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com>
__ublk_check_and_get_req() checks that the passed in offset is within the data length of the specified ublk request. However, only user copy (ublk_check_and_get_req()) supports accessing ublk request data at a nonzero offset. Zero-copy buffer registration (ublk_register_io_buf()) always passes 0 for the offset, so the check is unnecessary. Move the check from __ublk_check_and_get_req() to ublk_check_and_get_req(). Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com>
Add a function ublk_copy_user_integrity() to copy integrity information between a request and a user iov_iter. This mirrors the existing ublk_copy_user_pages() but operates on request integrity data instead of regular data. Check UBLKSRV_IO_INTEGRITY_FLAG in iocb->ki_pos in ublk_user_copy() to choose between copying data or integrity data. Signed-off-by: Stanley Zhang <stazhang@purestorage.com> [csander: change offset units from data bytes to integrity data bytes, test UBLKSRV_IO_INTEGRITY_FLAG after subtracting UBLKSRV_IO_BUF_OFFSET, fix CONFIG_BLK_DEV_INTEGRITY=n build, rebase on ublk user copy refactor] Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Now that all the components of the ublk integrity feature have been implemented, add UBLK_F_INTEGRITY to UBLK_F_ALL, conditional on block layer integrity support (CONFIG_BLK_DEV_INTEGRITY). This allows ublk servers to create ublk devices with UBLK_F_INTEGRITY set and UBLK_U_CMD_GET_FEATURES to report the feature as supported. Signed-off-by: Stanley Zhang <stazhang@purestorage.com> [csander: make feature conditional on CONFIG_BLK_DEV_INTEGRITY] Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
ublk user copy syscalls may be issued from any task, so they take a reference count on the struct ublk_io to check whether it is owned by the ublk server and prevent a concurrent UBLK_IO_COMMIT_AND_FETCH_REQ from completing the request. However, if the user copy syscall is issued on the io's daemon task, a concurrent UBLK_IO_COMMIT_AND_FETCH_REQ isn't possible, so the atomic reference count dance is unnecessary. Check for UBLK_IO_FLAG_OWNED_BY_SRV to ensure the request is dispatched to the sever and obtain the request from ublk_io's req field instead of looking it up on the tagset. Skip the reference count increment and decrement. Commit 8a8fe42 ("ublk: optimize UBLK_IO_REGISTER_IO_BUF on daemon task") made an analogous optimization for ublk zero copy buffer registration. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com>
Add support for printing the UBLK_F_INTEGRITY feature flag in the human-readable kublk features output. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Some block device integrity parameters are available in sysfs, but others are only accessible using the FS_IOC_GETLBMD_CAP ioctl. Add a metadata_size utility program to print out the logical block metadata size, PI offset, and PI size within the metadata. Example output: $ metadata_size /dev/ublkb0 metadata_size: 64 pi_offset: 56 pi_tuple_size: 8 Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Add integrity param command line arguments to kublk. Plumb these to struct ublk_params for the null and fault_inject targets, as they don't need to actually read or write the integrity data. Forbid the integrity params for loop or stripe until the integrity data copy is implemented. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
If integrity data is enabled for kublk, allocate an integrity buffer for each I/O. Extend ublk_user_copy() to copy the integrity data between the ublk request and the integrity buffer if the ublksrv_io_desc indicates that the request has integrity data. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
A subsequent commit will add support for using a backing file to store integrity data. Since integrity data is accessed in intervals of metadata_size, which may be much smaller than a logical block on the backing device, direct I/O cannot be used. Add an argument to backing_file_tgt_init() to specify the number of files to open for direct I/O. The remaining files will use buffered I/O. For now, continue to request direct I/O for all the files. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
To perform and end-to-end test of integrity information through a ublk device, we need to actually store it somewhere and retrieve it. Add this support to kublk's loop target. It uses a second backing file for the integrity data corresponding to the data stored in the first file. The integrity file is opened without O_DIRECT since it will be accessed at sub-block granularity. Each incoming read/write results in a pair of reads/writes, one to the data file, and one to the integrity file. If either backing I/O fails, the error is propagated to the ublk request. If both backing I/Os read/write some bytes, the ublk request is completed with the smaller of the number of blocks accessed by each I/O. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Add test case null_04 to exercise all the different integrity params. It creates 4 different ublk devices with different combinations of integrity arguments and verifies their integrity limits via sysfs and the metadata_size utility. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Add test case loop_08 to verify the ublk integrity data flow. It uses the kublk loop target to create a ublk device with integrity on top of backing data and integrity files. It then writes to the whole device with fio configured to generate integrity data. Then it reads back the whole device with fio configured to verify the integrity data. It also verifies that injected guard, reftag, and apptag corruptions are correctly detected. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
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Upstream branch: 528478e |
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Pull request for series with
subject: ublk: add support for integrity data
version: 2
url: https://patchwork.kernel.org/project/linux-block/list/?series=1038045