blk_add_request_payload(9) [centos man page]

BLK_ADD_REQUEST_PAYL(9) 					   Block Devices					   BLK_ADD_REQUEST_PAYL(9)

NAME

       blk_add_request_payload - add a payload to a request

SYNOPSIS

       void blk_add_request_payload(struct request * rq, struct page * page, unsigned int len);

ARGUMENTS

       rq
	   request to update

       page
	   page backing the payload

       len
	   length of the payload.

DESCRIPTION

       This allows to later add a payload to an already submitted request by a block driver. The driver needs to take care of freeing the payload
       itself.

       Note that this is a quite horrible hack and nothing but handling of discard requests should ever use it.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   BLK_ADD_REQUEST_PAYL(9)

KEYCTL_UPDATE(3)					    Linux Key Management Calls						  KEYCTL_UPDATE(3)

NAME

       keyctl_update - Update a key

SYNOPSIS

       #include <keyutils.h>

       long keyctl_update(key_serial_t key, const char *payload,
       size_t plen);

DESCRIPTION

       keyctl_update() updates the payload of a key if the key type permits it.

       The caller must have write permission on a key to be able update it.

       payload	and  plen  specify  the data for the new payload.  payload may be NULL and plen may be zero if the key type permits that.  The key
       type may reject the data if it's in the wrong format or in some other way invalid.

RETURN VALUE

       On success keyctl_update() returns 0.  On error, the value -1 will be returned and errno will have been set to an appropriate error.

ERRORS

       ENOKEY The key specified is invalid.

       EKEYEXPIRED
	      The key specified has expired.

       EKEYREVOKED
	      The key specified had been revoked.

       EINVAL The payload data was invalid.

       ENOMEM Insufficient memory to store the new payload.

       EDQUOT The key quota for this user would be exceeded by increasing the size of the key to accommodate the new payload.

       EACCES The key exists, but is not writable by the calling process.

       EOPNOTSUPP
	      The key type does not support the update operation on its keys.

LINKING

       This is a library function that can be found in libkeyutils.  When linking, -lkeyutils should be specified to the linker.

SEE ALSO

       keyctl(1),
       add_key(2),
       keyctl(2),
       request_key(2),
       keyctl_get_keyring_ID(3),
       keyctl_join_session_keyring(3),
       keyctl_revoke(3),
       keyctl_chown(3),
       keyctl_setperm(3),
       keyctl_describe(3),
       keyctl_clear(3),
       keyctl_link(3),
       keyctl_unlink(3),
       keyctl_search(3),
       keyctl_read(3),
       keyctl_instantiate(3),
       keyctl_negate(3),
       keyctl_set_reqkey_keyring(3),
       keyctl_set_timeout(3),
       keyctl_assume_authority(3),
       keyctl_describe_alloc(3),
       keyctl_read_alloc(3),
       request-key(8)

Linux								    4 May 2006							  KEYCTL_UPDATE(3)