| g_data.9 (126861) | g_data.9 (129381) |
|---|---|
| 1.\" 2.\" Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 8 unchanged lines hidden (view full) --- 17.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24.\" | 1.\" 2.\" Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 8 unchanged lines hidden (view full) --- 17.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24.\" |
| 25.\" $FreeBSD: head/share/man/man9/g_data.9 126861 2004-03-11 19:53:22Z pjd $ | 25.\" $FreeBSD: head/share/man/man9/g_data.9 129381 2004-05-18 11:33:37Z le $ |
| 26.\" 27.Dd January 16, 2004 28.Dt g_data 9 29.Os 30.Sh NAME 31.Nm g_read_data , 32.Nm g_write_data | 26.\" 27.Dd January 16, 2004 28.Dt g_data 9 29.Os 30.Sh NAME 31.Nm g_read_data , 32.Nm g_write_data |
| 33.Nd "read/write data through consumer" | 33.Nd "read/write data from/to GEOM consumer" |
| 34.Sh SYNOPSIS 35.In geom/geom.h 36.Ft "void *" 37.Fn g_read_data "struct g_consumer *cp" "off_t offset" "off_t length" "int *error" 38.Ft int 39.Fn g_write_data "struct g_consumer *cp" "off_t offset" "void *ptr" "off_t length" 40.Sh DESCRIPTION 41The 42.Fn g_read_data | 34.Sh SYNOPSIS 35.In geom/geom.h 36.Ft "void *" 37.Fn g_read_data "struct g_consumer *cp" "off_t offset" "off_t length" "int *error" 38.Ft int 39.Fn g_write_data "struct g_consumer *cp" "off_t offset" "void *ptr" "off_t length" 40.Sh DESCRIPTION 41The 42.Fn g_read_data |
| 43reads | 43function reads |
| 44.Fa length | 44.Fa length |
| 45bytes of data from a provider through attached consumer 46.Fa cp | 45bytes of data from the provider attached to consumer 46.Fa cp , |
| 47starting at offset 48.Fa offset . | 47starting at offset 48.Fa offset . |
| 49Memory for data is allocated inside | 49The buffer returned from |
| 50.Fn g_read_data | 50.Fn g_read_data |
| 51with | 51is allocated with |
| 52.Fn g_malloc , | 52.Fn g_malloc , |
| 53and should therefor be freed by the caller with the | 53so it should be freed by the caller with |
| 54.Fn g_free | 54.Fn g_free |
| 55function after use. | 55after use. |
| 56If the operation fails, an error value will be stored in the 57.Fa error 58argument if it is not 59.Dv NULL . 60.Pp 61The 62.Fn g_write_data | 56If the operation fails, an error value will be stored in the 57.Fa error 58argument if it is not 59.Dv NULL . 60.Pp 61The 62.Fn g_write_data |
| 63writes | 63function writes |
| 64.Fa length | 64.Fa length |
| 65bytes of data from address | 65bytes of data from the buffer pointed to by |
| 66.Fa ptr | 66.Fa ptr |
| 67to the provider attached to consumer 68.Fa cp , |
|
| 67starting at offset | 69starting at offset |
| 68.Fa offset 69to a provider through the attached consumer 70.Fa cp . | 70.Fa offset . |
| 71.Sh RESTRICTIONS/CONDITIONS | 71.Sh RESTRICTIONS/CONDITIONS |
| 72Length of data should be a multiple of the sectorsize for the provider | 72.Fa length 73should be a multiple of the provider's sectorsize |
| 73and less than or equal to 74.Dv DFLTPHYS 75.Dv ( DFLTPHYS is defined in 76.In sys/param.h ) . 77.Pp 78The topology lock must not be held. 79.Sh RETURN VALUES | 74and less than or equal to 75.Dv DFLTPHYS 76.Dv ( DFLTPHYS is defined in 77.In sys/param.h ) . 78.Pp 79The topology lock must not be held. 80.Sh RETURN VALUES |
| 81The |
|
| 80.Fn g_read_data | 82.Fn g_read_data |
| 81returns a pointer to the read data or | 83function returns a pointer to a data buffer or |
| 82.Dv NULL 83if an error occured. 84In that case an error value is stored in the 85.Fa error | 84.Dv NULL 85if an error occured. 86In that case an error value is stored in the 87.Fa error |
| 86argument unsless it is | 88argument unless it is |
| 87.Dv NULL . 88.Pp | 89.Dv NULL . 90.Pp |
| 91The |
|
| 89.Fn g_write_data | 92.Fn g_write_data |
| 90returns the value 0 if successful; otherwise an error code is returned. | 93function returns 0 if successful; otherwise an error code is returned. |
| 91.Sh ERRORS 92Possible errors: 93.Bl -tag -width Er 94.It Bq Er EIO 95Can not read data. 96.El 97.Sh SEE ALSO 98.Xr DECLARE_GEOM_CLASS 9 , --- 14 unchanged lines hidden --- | 94.Sh ERRORS 95Possible errors: 96.Bl -tag -width Er 97.It Bq Er EIO 98Can not read data. 99.El 100.Sh SEE ALSO 101.Xr DECLARE_GEOM_CLASS 9 , --- 14 unchanged lines hidden --- |