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authorMatthew R. Ochs <mrochs@linux.vnet.ibm.com>2016-08-09 18:39:52 -0500
committerMartin K. Petersen <martin.petersen@oracle.com>2016-08-23 22:23:41 -0400
commitcd34af40a09c678abad36304eb68e1774640e908 (patch)
treed376d13d6ff7304be180160b1ad63c5556f7577c /include/uapi/scsi
parent888baf069f49529f33c0b1dfb0fc4811dc0ca1d2 (diff)
scsi: cxlflash: Transition to application close model
Caching the adapter file descriptor and performing a close on behalf of an application is a poor design. This is due to the fact that once a file descriptor in installed, it is free to be altered without the knowledge of the cxlflash driver. This can lead to inconsistencies between the application and kernel. Furthermore, the nature of the former design is more exploitable and thus should be abandoned. To support applications performing a close on the adapter file that is associated with a context, a new flag is introduced to the user API to indicate to applications that they are responsible for the close following the cleanup (detach) of a context. The documentation is also updated to reflect this change in behavior. Inspired-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/uapi/scsi')
-rw-r--r--include/uapi/scsi/cxlflash_ioctl.h19
1 files changed, 14 insertions, 5 deletions
diff --git a/include/uapi/scsi/cxlflash_ioctl.h b/include/uapi/scsi/cxlflash_ioctl.h
index 2302f3ce5f86..6bf1f8a022b1 100644
--- a/include/uapi/scsi/cxlflash_ioctl.h
+++ b/include/uapi/scsi/cxlflash_ioctl.h
@@ -39,19 +39,28 @@ struct dk_cxlflash_hdr {
* at this time, this provides future flexibility.
*/
#define DK_CXLFLASH_ALL_PORTS_ACTIVE 0x0000000000000001ULL
+#define DK_CXLFLASH_APP_CLOSE_ADAP_FD 0x0000000000000002ULL
/*
- * Notes:
- * -----
+ * General Notes:
+ * -------------
* The 'context_id' field of all ioctl structures contains the context
* identifier for a context in the lower 32-bits (upper 32-bits are not
* to be used when identifying a context to the AFU). That said, the value
* in its entirety (all 64-bits) is to be treated as an opaque cookie and
* should be presented as such when issuing ioctls.
+ */
+
+/*
+ * DK_CXLFLASH_ATTACH Notes:
+ * ------------------------
+ * Read/write access permissions are specified via the O_RDONLY, O_WRONLY,
+ * and O_RDWR flags defined in the fcntl.h header file.
*
- * For DK_CXLFLASH_ATTACH ioctl, user specifies read/write access
- * permissions via the O_RDONLY, O_WRONLY, and O_RDWR flags defined in
- * the fcntl.h header file.
+ * A valid adapter file descriptor (fd >= 0) is only returned on the initial
+ * attach (successful) of a context. When a context is shared(reused), the user
+ * is expected to already 'know' the adapter file descriptor associated with the
+ * context.
*/
#define DK_CXLFLASH_ATTACH_REUSE_CONTEXT 0x8000000000000000ULL

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