block: return on congested block device

[mirror_ubuntu-artful-kernel.git] / include / linux / blk_types.h

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 61339bc444006a477bf3e84b32a1d8199a9e5f01..e210da6d14b8fb55716e261724c9f623c8240e8f 100644 (file)
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -17,6 +17,27 @@ struct io_context;
 struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *);
 
+/*
+ * Block error status values.  See block/blk-core:blk_errors for the details.
+ */
+typedef u8 __bitwise blk_status_t;
+#define        BLK_STS_OK 0
+#define BLK_STS_NOTSUPP                ((__force blk_status_t)1)
+#define BLK_STS_TIMEOUT                ((__force blk_status_t)2)
+#define BLK_STS_NOSPC          ((__force blk_status_t)3)
+#define BLK_STS_TRANSPORT      ((__force blk_status_t)4)
+#define BLK_STS_TARGET         ((__force blk_status_t)5)
+#define BLK_STS_NEXUS          ((__force blk_status_t)6)
+#define BLK_STS_MEDIUM         ((__force blk_status_t)7)
+#define BLK_STS_PROTECTION     ((__force blk_status_t)8)
+#define BLK_STS_RESOURCE       ((__force blk_status_t)9)
+#define BLK_STS_IOERR          ((__force blk_status_t)10)
+
+/* hack for device mapper, don't use elsewhere: */
+#define BLK_STS_DM_REQUEUE    ((__force blk_status_t)11)
+
+#define BLK_STS_AGAIN          ((__force blk_status_t)12)
+
 struct blk_issue_stat {
        u64 stat;
 };
@@ -28,7 +49,7 @@ struct blk_issue_stat {
 struct bio {
        struct bio              *bi_next;       /* request queue link */
        struct block_device     *bi_bdev;
-       int                     bi_error;
+       blk_status_t            bi_status;
        unsigned int            bi_opf;         /* bottom bits req flags,
                                                 * top bits REQ_OP. Use
                                                 * accessors.
@@ -205,6 +226,7 @@ enum req_flag_bits {
        /* command specific flags for REQ_OP_WRITE_ZEROES: */
        __REQ_NOUNMAP,          /* do not free blocks when zeroing */
 
+       __REQ_NOWAIT,           /* Don't wait if request will block */
        __REQ_NR_BITS,          /* stops here */
 };
 
@@ -223,6 +245,7 @@ enum req_flag_bits {
 #define REQ_BACKGROUND         (1ULL << __REQ_BACKGROUND)
 
 #define REQ_NOUNMAP            (1ULL << __REQ_NOUNMAP)
+#define REQ_NOWAIT             (1ULL << __REQ_NOWAIT)
 
 #define REQ_FAILFAST_MASK \
        (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)