diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/genhd.h | 6 | ||||
| -rw-r--r-- | include/linux/loop.h | 1 | ||||
| -rw-r--r-- | include/xen/interface/io/blkif.h | 36 |
3 files changed, 41 insertions, 2 deletions
diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 6957350e122f..9de31bc98c88 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -131,6 +131,7 @@ struct hd_struct { #define GENHD_FL_EXT_DEVT 64 /* allow extended devt */ #define GENHD_FL_NATIVE_CAPACITY 128 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256 +#define GENHD_FL_NO_PART_SCAN 512 enum { DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */ @@ -238,9 +239,10 @@ static inline int disk_max_parts(struct gendisk *disk) return disk->minors; } -static inline bool disk_partitionable(struct gendisk *disk) +static inline bool disk_part_scan_enabled(struct gendisk *disk) { - return disk_max_parts(disk) > 1; + return disk_max_parts(disk) > 1 && + !(disk->flags & GENHD_FL_NO_PART_SCAN); } static inline dev_t disk_devt(struct gendisk *disk) diff --git a/include/linux/loop.h b/include/linux/loop.h index a06880689115..11a41a8f08eb 100644 --- a/include/linux/loop.h +++ b/include/linux/loop.h @@ -74,6 +74,7 @@ struct loop_device { enum { LO_FLAGS_READ_ONLY = 1, LO_FLAGS_AUTOCLEAR = 4, + LO_FLAGS_PARTSCAN = 8, }; #include <asm/posix_types.h> /* for __kernel_old_dev_t */ diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index 3d5d6db864fe..9324488f23f0 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -57,6 +57,36 @@ typedef uint64_t blkif_sector_t; * "feature-flush-cache" node! */ #define BLKIF_OP_FLUSH_DISKCACHE 3 + +/* + * Recognised only if "feature-discard" is present in backend xenbus info. + * The "feature-discard" node contains a boolean indicating whether trim + * (ATA) or unmap (SCSI) - conviently called discard requests are likely + * to succeed or fail. Either way, a discard request + * may fail at any time with BLKIF_RSP_EOPNOTSUPP if it is unsupported by + * the underlying block-device hardware. The boolean simply indicates whether + * or not it is worthwhile for the frontend to attempt discard requests. + * If a backend does not recognise BLKIF_OP_DISCARD, it should *not* + * create the "feature-discard" node! + * + * Discard operation is a request for the underlying block device to mark + * extents to be erased. However, discard does not guarantee that the blocks + * will be erased from the device - it is just a hint to the device + * controller that these blocks are no longer in use. What the device + * controller does with that information is left to the controller. + * Discard operations are passed with sector_number as the + * sector index to begin discard operations at and nr_sectors as the number of + * sectors to be discarded. The specified sectors should be discarded if the + * underlying block device supports trim (ATA) or unmap (SCSI) operations, + * or a BLKIF_RSP_EOPNOTSUPP should be returned. + * More information about trim/unmap operations at: + * http://t13.org/Documents/UploadedDocuments/docs2008/ + * e07154r6-Data_Set_Management_Proposal_for_ATA-ACS2.doc + * http://www.seagate.com/staticfiles/support/disc/manuals/ + * Interface%20manuals/100293068c.pdf + */ +#define BLKIF_OP_DISCARD 5 + /* * Maximum scatter/gather segments per request. * This is carefully chosen so that sizeof(struct blkif_ring) <= PAGE_SIZE. @@ -74,6 +104,11 @@ struct blkif_request_rw { } seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; }; +struct blkif_request_discard { + blkif_sector_t sector_number; + uint64_t nr_sectors; +}; + struct blkif_request { uint8_t operation; /* BLKIF_OP_??? */ uint8_t nr_segments; /* number of segments */ @@ -81,6 +116,7 @@ struct blkif_request { uint64_t id; /* private guest value, echoed in resp */ union { struct blkif_request_rw rw; + struct blkif_request_discard discard; } u; }; |