diff options
Diffstat (limited to 'block/file-posix.c')
| -rw-r--r-- | block/file-posix.c | 160 |
1 files changed, 132 insertions, 28 deletions
diff --git a/block/file-posix.c b/block/file-posix.c index ef52ed9..8c73867 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -41,6 +41,7 @@ #include "scsi/pr-manager.h" #include "scsi/constants.h" +#include "scsi/utils.h" #if defined(__APPLE__) && (__MACH__) #include <sys/ioctl.h> @@ -72,6 +73,7 @@ #include <linux/blkzoned.h> #endif #include <linux/cdrom.h> +#include <linux/dm-ioctl.h> #include <linux/fd.h> #include <linux/fs.h> #include <linux/hdreg.h> @@ -138,6 +140,22 @@ #define RAW_LOCK_PERM_BASE 100 #define RAW_LOCK_SHARED_BASE 200 +/* + * Multiple retries are mostly meant for two separate scenarios: + * + * - DM_MPATH_PROBE_PATHS returns success, but before SG_IO completes, another + * path goes down. + * + * - DM_MPATH_PROBE_PATHS failed all paths in the current path group, so we have + * to send another SG_IO to switch to another path group to probe the paths in + * it. + * + * Even if each path is in a separate path group (path_grouping_policy set to + * failover), it's rare to have more than eight path groups - and even then + * pretty unlikely that only bad path groups would be chosen in eight retries. + */ +#define SG_IO_MAX_RETRIES 8 + typedef struct BDRVRawState { int fd; bool use_lock; @@ -165,6 +183,7 @@ typedef struct BDRVRawState { bool use_linux_aio:1; bool has_laio_fdsync:1; bool use_linux_io_uring:1; + bool use_mpath:1; int page_cache_inconsistent; /* errno from fdatasync failure */ bool has_fallocate; bool needs_alignment; @@ -785,17 +804,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, } #endif - if (S_ISBLK(st.st_mode)) { -#ifdef __linux__ - /* On Linux 3.10, BLKDISCARD leaves stale data in the page cache. Do - * not rely on the contents of discarded blocks unless using O_DIRECT. - * Same for BLKZEROOUT. - */ - if (!(bs->open_flags & BDRV_O_NOCACHE)) { - s->has_write_zeroes = false; - } -#endif - } #ifdef __FreeBSD__ if (S_ISCHR(st.st_mode)) { /* @@ -2556,9 +2564,9 @@ static inline bool raw_check_linux_aio(BDRVRawState *s) } #endif -static int coroutine_fn raw_co_prw(BlockDriverState *bs, int64_t *offset_ptr, - uint64_t bytes, QEMUIOVector *qiov, int type, - int flags) +static int coroutine_fn GRAPH_RDLOCK +raw_co_prw(BlockDriverState *bs, int64_t *offset_ptr, uint64_t bytes, + QEMUIOVector *qiov, int type, int flags) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; @@ -2617,7 +2625,7 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, int64_t *offset_ptr, ret = raw_thread_pool_submit(handle_aiocb_rw, &acb); if (ret == 0 && (flags & BDRV_REQ_FUA)) { /* TODO Use pwritev2() instead if it's available */ - ret = raw_co_flush_to_disk(bs); + ret = bdrv_co_flush(bs); } goto out; /* Avoid the compiler err of unused label */ @@ -2652,16 +2660,16 @@ out: return ret; } -static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset, - int64_t bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags) +static int coroutine_fn GRAPH_RDLOCK +raw_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, + QEMUIOVector *qiov, BdrvRequestFlags flags) { return raw_co_prw(bs, &offset, bytes, qiov, QEMU_AIO_READ, flags); } -static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, int64_t offset, - int64_t bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags) +static int coroutine_fn GRAPH_RDLOCK +raw_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, + QEMUIOVector *qiov, BdrvRequestFlags flags) { return raw_co_prw(bs, &offset, bytes, qiov, QEMU_AIO_WRITE, flags); } @@ -3273,7 +3281,7 @@ static int find_allocation(BlockDriverState *bs, off_t start, * well exceed it. */ static int coroutine_fn raw_co_block_status(BlockDriverState *bs, - bool want_zero, + unsigned int mode, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, @@ -3289,7 +3297,8 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs, return ret; } - if (!want_zero) { + if (!(mode & BDRV_WANT_ZERO)) { + /* There is no backing file - all bytes are allocated in this file. */ *pnum = bytes; *map = offset; *file = bs; @@ -3597,10 +3606,11 @@ static int coroutine_fn raw_co_zone_mgmt(BlockDriverState *bs, BlockZoneOp op, #endif #if defined(CONFIG_BLKZONED) -static int coroutine_fn raw_co_zone_append(BlockDriverState *bs, - int64_t *offset, - QEMUIOVector *qiov, - BdrvRequestFlags flags) { +static int coroutine_fn GRAPH_RDLOCK +raw_co_zone_append(BlockDriverState *bs, + int64_t *offset, + QEMUIOVector *qiov, + BdrvRequestFlags flags) { assert(flags == 0); int64_t zone_size_mask = bs->bl.zone_size - 1; int64_t iov_len = 0; @@ -4263,15 +4273,105 @@ hdev_open_Mac_error: /* Since this does ioctl the device must be already opened */ bs->sg = hdev_is_sg(bs); + /* sg devices aren't even block devices and can't use dm-mpath */ + s->use_mpath = !bs->sg; + return ret; } #if defined(__linux__) +#if defined(DM_MPATH_PROBE_PATHS) +static bool coroutine_fn sgio_path_error(int ret, sg_io_hdr_t *io_hdr) +{ + if (ret < 0) { + switch (ret) { + case -ENODEV: + return true; + case -EAGAIN: + /* + * The device is probably suspended. This happens while the dm table + * is reloaded, e.g. because a path is added or removed. This is an + * operation that should complete within 1ms, so just wait a bit and + * retry. + * + * If the device was suspended for another reason, we'll wait and + * retry SG_IO_MAX_RETRIES times. This is a tolerable delay before + * we return an error and potentially stop the VM. + */ + qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); + return true; + default: + return false; + } + } + + if (io_hdr->host_status != SCSI_HOST_OK) { + return true; + } + + switch (io_hdr->status) { + case GOOD: + case CONDITION_GOOD: + case INTERMEDIATE_GOOD: + case INTERMEDIATE_C_GOOD: + case RESERVATION_CONFLICT: + case COMMAND_TERMINATED: + return false; + case CHECK_CONDITION: + return !scsi_sense_buf_is_guest_recoverable(io_hdr->sbp, + io_hdr->mx_sb_len); + default: + return true; + } +} + +static bool coroutine_fn hdev_co_ioctl_sgio_retry(RawPosixAIOData *acb, int ret) +{ + BDRVRawState *s = acb->bs->opaque; + RawPosixAIOData probe_acb; + + if (!s->use_mpath) { + return false; + } + + if (!sgio_path_error(ret, acb->ioctl.buf)) { + return false; + } + + probe_acb = (RawPosixAIOData) { + .bs = acb->bs, + .aio_type = QEMU_AIO_IOCTL, + .aio_fildes = s->fd, + .aio_offset = 0, + .ioctl = { + .buf = NULL, + .cmd = DM_MPATH_PROBE_PATHS, + }, + }; + + ret = raw_thread_pool_submit(handle_aiocb_ioctl, &probe_acb); + if (ret == -ENOTTY) { + s->use_mpath = false; + } else if (ret == -EAGAIN) { + /* The device might be suspended for a table reload, worth retrying */ + return true; + } + + return ret == 0; +} +#else +static bool coroutine_fn hdev_co_ioctl_sgio_retry(RawPosixAIOData *acb, int ret) +{ + return false; +} +#endif /* DM_MPATH_PROBE_PATHS */ + static int coroutine_fn hdev_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; + int retries = SG_IO_MAX_RETRIES; int ret; ret = fd_open(bs); @@ -4299,7 +4399,11 @@ hdev_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) }, }; - return raw_thread_pool_submit(handle_aiocb_ioctl, &acb); + do { + ret = raw_thread_pool_submit(handle_aiocb_ioctl, &acb); + } while (req == SG_IO && retries-- && hdev_co_ioctl_sgio_retry(&acb, ret)); + + return ret; } #endif /* linux */ |