include/block/block-common.h

16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 #include "qapi/qapi-types-block-core.h"
31  * co_wrapper{*}: Function specifiers used by block-coroutine-wrapper.py
34  * generated by scripts/block-coroutine-wrapper.py
36  * Usage: read docs/devel/block-coroutine-wrapper.rst
39  * - co_wrapper functions can be called by only non-coroutine context, because
41  * - co_wrapper_mixed functions can be called by both coroutine and
42  *   non-coroutine context.
43  * - co_wrapper_bdrv_rdlock are co_wrapper functions but automatically take and
45  * - co_wrapper_mixed_bdrv_rdlock are co_wrapper_mixed functions but
58  * no_co_wrapper: Function specifier used by block-coroutine-wrapper.py
61  * scripts/block-coroutine-wrapper.py.
65  * scheduling a BH in the bottom half that runs the respective non-coroutine
85 typedef enum BlockZoneOp {
92 typedef enum BlockZoneModel {
94     BLK_Z_HM = 0x1, /* Host-managed zoned block device */
95     BLK_Z_HA = 0x2, /* Host-aware zoned block device */
98 typedef enum BlockZoneState {
109 typedef enum BlockZoneType {
160 typedef enum {
167      * that the result will read back as zeroes. The flag is only passed to the
203      * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
218     /* Mask of valid flags */
242 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening
243                                       read-write fails */
246 #define BDRV_O_CBW_DISCARD_SOURCE 0x80000 /* for copy-before-write filter */
255 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
256 #define BDRV_OPT_READ_ONLY      "read-only"
257 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
259 #define BDRV_OPT_FORCE_SHARE    "force-share"
279  * To achieve it, and in the same time use some pretty number as maximum disk
287  * Allocation status flags for bdrv_block_status() and friends.
289  * Public flags:
291  * BDRV_BLOCK_ZERO: offset reads as zero
300  * Internal flags:
301  * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
313  * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
316  *  t    t        t       sectors read as zero, returned file is zero at offset
317  *  t    f        t       sectors read as valid from file at offset
318  *  f    t        t       sectors preallocated, read as zero, returned file not
322  *  t    t        f       sectors preallocated, read as zero, unknown offset
324  *  f    t        f       not allocated or unknown offset, read as zero
337  * Block status hints: the bitwise-or of these flags emphasize what
351     int flags;  member
364 typedef enum BlockOpType {
384 enum {
388      * self-consistent, representing the contents of a disk at a specific
405      * As the BLK_PERM_WRITE permission is strictly stronger, either is
414      * There was a now-removed bit BLK_PERM_GRAPH_MOD, with value of 0x10. QEMU
415      * 6.1 and earlier may still lock the corresponding byte in block/file-posix
431  * Flags that parent nodes assign to child nodes to specify what kind of
438  * = Connection with bs->children, bs->file and bs->backing fields =
442  * Filter drivers have drv->is_filter = true.
446  * copy-before-write filter, which also has its target DATA child).
450  * For most filters, the filtered child is linked in bs->file, bs->backing is
451  * NULL.  For some filters (as an exception), it is the other way around; those
452  * drivers will have drv->filtered_child_is_backing set to true (see that
455  * 2. "raw" driver (block/raw-format.c)
457  * Formally it's not a filter (drv->is_filter = false)
459  * bs->backing is always NULL
461  * Only has one child, linked in bs->file. Its role is either FILTERED|PRIMARY
468  * May have at most one COW child. In this case it's linked in bs->backing.
469  * Otherwise bs->backing is NULL. COW child is never PRIMARY.
471  * May have at most one PRIMARY child. In this case it's linked in bs->file.
472  * Otherwise bs->file is NULL.
476 enum BdrvChildRoleBits {
485      * Any node may have an arbitrary number of metadata-storing
491      * A child that always presents exactly the same visible data as
516     /* Useful combination of flags */
535 typedef enum {
566 int bdrv_parse_aio(const char *mode, int *flags);
567 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
568 int bdrv_parse_discard_flags(const char *mode, int *flags);