blocktrans.c File Reference

Block device translator. More...

#include <stdlib.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/iobuf.h>
#include <ipxe/xfer.h>
#include <ipxe/blockdev.h>
#include <ipxe/blocktrans.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static int	blktrans_xferbuf_realloc (struct xfer_buffer *xferbuf, size_t len)
	Reallocate block device translator data buffer. More...
static void	blktrans_xferbuf_write (struct xfer_buffer *xferbuf, size_t offset, const void *data, size_t len)
	Write data to block device translator data buffer. More...
static void	blktrans_xferbuf_read (struct xfer_buffer *xferbuf, size_t offset, void *data, size_t len)
	Read data from block device translator data buffer. More...
static void	blktrans_close (struct block_translator *blktrans, int rc)
	Close block device translator. More...
static int	blktrans_deliver (struct block_translator *blktrans, struct io_buffer *iobuf, struct xfer_metadata *meta)
	Deliver data. More...
static struct xfer_buffer *	blktrans_buffer (struct block_translator *blktrans)
	Get underlying data transfer buffer. More...
int	block_translate (struct interface *block, userptr_t buffer, size_t size)
	Insert block device translator. More...

Variables
static struct xfer_buffer_operations	blktrans_xferbuf_operations
	Block device translator data transfer buffer operations. More...
static struct interface_operation	blktrans_block_operations []
	Block device translator block device interface operations. More...
static struct interface_descriptor	blktrans_block_desc
	Block device translator block device interface descriptor. More...
static struct interface_operation	blktrans_xfer_operations []
	Block device translator data transfer interface operations. More...
static struct interface_descriptor	blktrans_xfer_desc
	Block device translator data transfer interface descriptor. More...

Detailed Description

Block device translator.

Definition in file blocktrans.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

blktrans_xferbuf_realloc()

static int blktrans_xferbuf_realloc ( struct xfer_buffer *  xferbuf, size_t  len  )

static

Reallocate block device translator data buffer.

Parameters

xferbuf	Data transfer buffer
len	New length (or zero to free buffer)

Return values

rc	Return status code

Definition at line 48 of file blocktrans.c.

                                                   {
        struct block_translator *blktrans =
                container_of ( xferbuf, struct block_translator, xferbuf );

        /* Record length, if applicable */
        if ( blktrans->buffer ) {

                /* We have a (non-reallocatable) data buffer */
                return -ENOTSUP;

        } else {

                /* Record length (for block device capacity) */
                xferbuf->len = len;
                return 0;
        }
}

References block_translator::buffer, container_of, ENOTSUP, len, xfer_buffer::len, and block_translator::xferbuf.

blktrans_xferbuf_write()

static void blktrans_xferbuf_write ( struct xfer_buffer *  xferbuf, size_t  offset, const void *  data, size_t  len  )

static

Write data to block device translator data buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to copy
len	Length of data

Definition at line 75 of file blocktrans.c.

                                                                    {
        struct block_translator *blktrans =
                container_of ( xferbuf, struct block_translator, xferbuf );

        /* Write data to buffer, if applicable */
        if ( blktrans->buffer ) {

                /* Write data to buffer */
                copy_to_user ( blktrans->buffer, offset, data, len );

        } else {

                /* Sanity check */
                assert ( len == 0 );
        }
}

References assert(), block_translator::buffer, container_of, copy_to_user(), data, len, offset, and block_translator::xferbuf.

blktrans_xferbuf_read()

static void blktrans_xferbuf_read ( struct xfer_buffer *  xferbuf, size_t  offset, void *  data, size_t  len  )

static

Read data from block device translator data buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to read
len	Length of data

Definition at line 101 of file blocktrans.c.

                                                             {
        struct block_translator *blktrans =
                container_of ( xferbuf, struct block_translator, xferbuf );

        /* Read data from buffer, if applicable */
        if ( blktrans->buffer ) {

                /* Read data from buffer */
                copy_from_user ( data, blktrans->buffer, offset, len );

        } else {

                /* Sanity check */
                assert ( len == 0 );
        }
}

References assert(), block_translator::buffer, container_of, copy_from_user(), data, len, offset, and block_translator::xferbuf.

blktrans_close()

static void blktrans_close ( struct block_translator *  blktrans, int  rc  )

static

Close block device translator.

Parameters

blktrans	Block device translator
rc	Reason for close

Definition at line 132 of file blocktrans.c.

                                                                         {
        struct block_device_capacity capacity;

        /* Report block device capacity, if applicable */
        if ( ( rc == 0 ) && ( blktrans->blksize ) ) {

                /* Construct block device capacity */
                capacity.blocks =
                        ( blktrans->xferbuf.len / blktrans->blksize );
                capacity.blksize = blktrans->blksize;
                capacity.max_count = -1U;

                /* Report block device capacity */
                block_capacity ( &blktrans->block, &capacity );
        }

        /* Shut down interfaces */
        intf_shutdown ( &blktrans->xfer, rc );
        intf_shutdown ( &blktrans->block, rc );
}

References block_device_capacity::blksize, block_translator::blksize, block_translator::block, block_capacity(), block_device_capacity::blocks, intf_shutdown(), xfer_buffer::len, block_device_capacity::max_count, rc, block_translator::xfer, and block_translator::xferbuf.

Referenced by blktrans_deliver().

blktrans_deliver()

static int blktrans_deliver ( struct block_translator *  blktrans, struct io_buffer *  iobuf, struct xfer_metadata *  meta  )

static

Deliver data.

Parameters

blktrans	Block device translator
iobuf	I/O buffer
meta	Data transfer metadata

Return values

rc	Return status code

Definition at line 161 of file blocktrans.c.

                                                           {
        int rc;

        /* Deliver to buffer */
        if ( ( rc = xferbuf_deliver ( &blktrans->xferbuf, iob_disown ( iobuf ),
                                      meta ) ) != 0 ) {
                DBGC ( blktrans, "BLKTRANS %p could not deliver: %s\n",
                       blktrans, strerror ( rc ) );
                goto err;
        }

        return 0;

 err:
        blktrans_close ( blktrans, rc );
        return rc;
}

References blktrans_close(), DBGC, iob_disown, meta(), rc, strerror(), block_translator::xferbuf, and xferbuf_deliver().

blktrans_buffer()

static struct xfer_buffer* blktrans_buffer ( struct block_translator *  blktrans )

static

Get underlying data transfer buffer.

Parameters

blktrans

Block device translator

Return values

xferbuf

Data transfer buffer

Definition at line 188 of file blocktrans.c.

                                                      {

        return &blktrans->xferbuf;
}

References block_translator::xferbuf.

block_translate()

int block_translate	(	struct interface *	block,
		userptr_t	buffer,
		size_t	size
	)

Insert block device translator.

Parameters

block	Block device interface
buffer	Data buffer (or UNULL)
size	Length of data buffer, or block size

Return values

rc	Return status code

Definition at line 223 of file blocktrans.c.

                                                                               {
        struct block_translator *blktrans;
        int rc;

        /* Allocate and initialise structure */
        blktrans = zalloc ( sizeof ( *blktrans ) );
        if ( ! blktrans ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        ref_init ( &blktrans->refcnt, NULL );
        intf_init ( &blktrans->block, &blktrans_block_desc, &blktrans->refcnt );
        intf_init ( &blktrans->xfer, &blktrans_xfer_desc, &blktrans->refcnt );
        blktrans->xferbuf.op = &blktrans_xferbuf_operations;
        blktrans->buffer = buffer;
        if ( buffer ) {
                blktrans->xferbuf.len = size;
        } else {
                blktrans->blksize = size;
        }

        /* Attach to interfaces, mortalise self, and return */
        intf_insert ( block, &blktrans->block, &blktrans->xfer );
        ref_put ( &blktrans->refcnt );

        DBGC2 ( blktrans, "BLKTRANS %p created", blktrans );
        if ( buffer ) {
                DBGC2 ( blktrans, " for %#lx+%#zx",
                        user_to_phys ( buffer, 0 ), size );
        }
        DBGC2 ( blktrans, "\n" );
        return 0;

        ref_put ( &blktrans->refcnt );
 err_alloc:
        return rc;
}

References block_translator::blksize, blktrans_block_desc, blktrans_xfer_desc, blktrans_xferbuf_operations, block, block_translator::block, buffer, block_translator::buffer, DBGC2, ENOMEM, intf_init(), intf_insert(), xfer_buffer::len, NULL, xfer_buffer::op, rc, ref_init, ref_put, block_translator::refcnt, size, user_to_phys(), block_translator::xfer, block_translator::xferbuf, and zalloc().

Referenced by http_block_read(), and http_block_read_capacity().

Variable Documentation

blktrans_xferbuf_operations

struct xfer_buffer_operations blktrans_xferbuf_operations

static

Initial value:

= {
        .realloc = blktrans_xferbuf_realloc,
        .write = blktrans_xferbuf_write,
        .read = blktrans_xferbuf_read,
}

Block device translator data transfer buffer operations.

Definition at line 120 of file blocktrans.c.

Referenced by block_translate().

blktrans_block_operations

struct interface_operation blktrans_block_operations[]

static

Initial value:

= {
        INTF_OP ( intf_close, struct block_translator *, blktrans_close ),
}

Block device translator block device interface operations.

Definition at line 194 of file blocktrans.c.

blktrans_block_desc

struct interface_descriptor blktrans_block_desc

static

Initial value:

=
        INTF_DESC_PASSTHRU ( struct block_translator, block,
                             blktrans_block_operations, xfer )

Block device translator block device interface descriptor.

Definition at line 199 of file blocktrans.c.

Referenced by block_translate().

blktrans_xfer_operations

struct interface_operation blktrans_xfer_operations[]

static

Initial value:

= {
        INTF_OP ( xfer_deliver, struct block_translator *, blktrans_deliver ),
        INTF_OP ( xfer_buffer, struct block_translator *, blktrans_buffer ),
        INTF_OP ( intf_close, struct block_translator *, blktrans_close ),
}

Block device translator data transfer interface operations.

Definition at line 204 of file blocktrans.c.

blktrans_xfer_desc

struct interface_descriptor blktrans_xfer_desc

static

Initial value:

=
        INTF_DESC_PASSTHRU ( struct block_translator, xfer,
                             blktrans_xfer_operations, block )

Block device translator data transfer interface descriptor.

Definition at line 211 of file blocktrans.c.

Referenced by block_translate().