/* * Block driver for RAW files (posix) * * Copyright (c) 2006 Fabrice Bellard * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "qemu/osdep.h" #include "qemu-common.h" #include "qapi/error.h" #include "qemu/cutils.h" #include "qemu/error-report.h" #include "block/block_int.h" #include "qemu/module.h" #include "qemu/option.h" #include "trace.h" #include "block/thread-pool.h" #include "qemu/iov.h" #include "block/raw-aio.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp/qstring.h" #include "scsi/pr-manager.h" #include "scsi/constants.h" #if defined(__APPLE__) && (__MACH__) #include #include #include #include #include #include #include //#include #include #include #endif #ifdef __sun__ #define _POSIX_PTHREAD_SEMANTICS 1 #include #endif #ifdef __linux__ #include #include #include #include #include #include #include #include #ifdef __s390__ #include #endif #ifndef FS_NOCOW_FL #define FS_NOCOW_FL 0x00800000 /* Do not cow file */ #endif #endif #if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_FALLOCATE_ZERO_RANGE) #include #endif #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) #include #include #endif #ifdef __OpenBSD__ #include #include #include #endif #ifdef __NetBSD__ #include #include #include #include #endif #ifdef __DragonFly__ #include #include #endif #ifdef CONFIG_XFS #include #endif #include "trace.h" /* OS X does not have O_DSYNC */ #ifndef O_DSYNC #ifdef O_SYNC #define O_DSYNC O_SYNC #elif defined(O_FSYNC) #define O_DSYNC O_FSYNC #endif #endif /* Approximate O_DIRECT with O_DSYNC if O_DIRECT isn't available */ #ifndef O_DIRECT #define O_DIRECT O_DSYNC #endif #define FTYPE_FILE 0 #define FTYPE_CD 1 #define MAX_BLOCKSIZE 4096 /* Posix file locking bytes. Libvirt takes byte 0, we start from higher bytes, * leaving a few more bytes for its future use. */ #define RAW_LOCK_PERM_BASE 100 #define RAW_LOCK_SHARED_BASE 200 typedef struct BDRVRawState { int fd; bool use_lock; int type; int open_flags; size_t buf_align; /* The current permissions. */ uint64_t perm; uint64_t shared_perm; /* The perms bits whose corresponding bytes are already locked in * s->fd. */ uint64_t locked_perm; uint64_t locked_shared_perm; int perm_change_fd; int perm_change_flags; BDRVReopenState *reopen_state; #ifdef CONFIG_XFS bool is_xfs:1; #endif bool has_discard:1; bool has_write_zeroes:1; bool discard_zeroes:1; bool use_linux_aio:1; bool page_cache_inconsistent:1; bool has_fallocate; bool needs_alignment; bool drop_cache; bool check_cache_dropped; PRManager *pr_mgr; } BDRVRawState; typedef struct BDRVRawReopenState { int fd; int open_flags; bool drop_cache; bool check_cache_dropped; } BDRVRawReopenState; static int fd_open(BlockDriverState *bs); static int64_t raw_getlength(BlockDriverState *bs); typedef struct RawPosixAIOData { BlockDriverState *bs; int aio_type; int aio_fildes; off_t aio_offset; uint64_t aio_nbytes; union { struct { struct iovec *iov; int niov; } io; struct { uint64_t cmd; void *buf; } ioctl; struct { int aio_fd2; off_t aio_offset2; } copy_range; struct { PreallocMode prealloc; Error **errp; } truncate; }; } RawPosixAIOData; #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) static int cdrom_reopen(BlockDriverState *bs); #endif #if defined(__NetBSD__) static int raw_normalize_devicepath(const char **filename, Error **errp) { static char namebuf[PATH_MAX]; const char *dp, *fname; struct stat sb; fname = *filename; dp = strrchr(fname, '/'); if (lstat(fname, &sb) < 0) { error_setg_file_open(errp, errno, fname); return -errno; } if (!S_ISBLK(sb.st_mode)) { return 0; } if (dp == NULL) { snprintf(namebuf, PATH_MAX, "r%s", fname); } else { snprintf(namebuf, PATH_MAX, "%.*s/r%s", (int)(dp - fname), fname, dp + 1); } *filename = namebuf; warn_report("%s is a block device, using %s", fname, *filename); return 0; } #else static int raw_normalize_devicepath(const char **filename, Error **errp) { return 0; } #endif /* * Get logical block size via ioctl. On success store it in @sector_size_p. */ static int probe_logical_blocksize(int fd, unsigned int *sector_size_p) { unsigned int sector_size; bool success = false; int i; errno = ENOTSUP; static const unsigned long ioctl_list[] = { #ifdef BLKSSZGET BLKSSZGET, #endif #ifdef DKIOCGETBLOCKSIZE DKIOCGETBLOCKSIZE, #endif #ifdef DIOCGSECTORSIZE DIOCGSECTORSIZE, #endif }; /* Try a few ioctls to get the right size */ for (i = 0; i < (int)ARRAY_SIZE(ioctl_list); i++) { if (ioctl(fd, ioctl_list[i], §or_size) >= 0) { *sector_size_p = sector_size; success = true; } } return success ? 0 : -errno; } /** * Get physical block size of @fd. * On success, store it in @blk_size and return 0. * On failure, return -errno. */ static int probe_physical_blocksize(int fd, unsigned int *blk_size) { #ifdef BLKPBSZGET if (ioctl(fd, BLKPBSZGET, blk_size) < 0) { return -errno; } return 0; #else return -ENOTSUP; #endif } /* Check if read is allowed with given memory buffer and length. * * This function is used to check O_DIRECT memory buffer and request alignment. */ static bool raw_is_io_aligned(int fd, void *buf, size_t len) { ssize_t ret = pread(fd, buf, len, 0); if (ret >= 0) { return true; } #ifdef __linux__ /* The Linux kernel returns EINVAL for misaligned O_DIRECT reads. Ignore * other errors (e.g. real I/O error), which could happen on a failed * drive, since we only care about probing alignment. */ if (errno != EINVAL) { return true; } #endif return false; } static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp) { BDRVRawState *s = bs->opaque; char *buf; size_t max_align = MAX(MAX_BLOCKSIZE, getpagesize()); size_t alignments[] = {1, 512, 1024, 2048, 4096}; /* For SCSI generic devices the alignment is not really used. With buffered I/O, we don't have any restrictions. */ if (bdrv_is_sg(bs) || !s->needs_alignment) { bs->bl.request_alignment = 1; s->buf_align = 1; return; } bs->bl.request_alignment = 0; s->buf_align = 0; /* Let's try to use the logical blocksize for the alignment. */ if (probe_logical_blocksize(fd, &bs->bl.request_alignment) < 0) { bs->bl.request_alignment = 0; } #ifdef CONFIG_XFS if (s->is_xfs) { struct dioattr da; if (xfsctl(NULL, fd, XFS_IOC_DIOINFO, &da) >= 0) { bs->bl.request_alignment = da.d_miniosz; /* The kernel returns wrong information for d_mem */ /* s->buf_align = da.d_mem; */ } } #endif /* * If we could not get the sizes so far, we can only guess them. First try * to detect request alignment, since it is more likely to succeed. Then * try to detect buf_align, which cannot be detected in some cases (e.g. * Gluster). If buf_align cannot be detected, we fallback to the value of * request_alignment. */ if (!bs->bl.request_alignment) { int i; size_t align; buf = qemu_memalign(max_align, max_align); for (i = 0; i < ARRAY_SIZE(alignments); i++) { align = alignments[i]; if (raw_is_io_aligned(fd, buf, align)) { /* Fallback to safe value. */ bs->bl.request_alignment = (align != 1) ? align : max_align; break; } } qemu_vfree(buf); } if (!s->buf_align) { int i; size_t align; buf = qemu_memalign(max_align, 2 * max_align); for (i = 0; i < ARRAY_SIZE(alignments); i++) { align = alignments[i]; if (raw_is_io_aligned(fd, buf + align, max_align)) { /* Fallback to request_aligment. */ s->buf_align = (align != 1) ? align : bs->bl.request_alignment; break; } } qemu_vfree(buf); } if (!s->buf_align || !bs->bl.request_alignment) { error_setg(errp, "Could not find working O_DIRECT alignment"); error_append_hint(errp, "Try cache.direct=off\n"); } } static void raw_parse_flags(int bdrv_flags, int *open_flags, bool has_writers) { bool read_write = false; assert(open_flags != NULL); *open_flags |= O_BINARY; *open_flags &= ~O_ACCMODE; if (bdrv_flags & BDRV_O_AUTO_RDONLY) { read_write = has_writers; } else if (bdrv_flags & BDRV_O_RDWR) { read_write = true; } if (read_write) { *open_flags |= O_RDWR; } else { *open_flags |= O_RDONLY; } /* Use O_DSYNC for write-through caching, no flags for write-back caching, * and O_DIRECT for no caching. */ if ((bdrv_flags & BDRV_O_NOCACHE)) { *open_flags |= O_DIRECT; } } static void raw_parse_filename(const char *filename, QDict *options, Error **errp) { bdrv_parse_filename_strip_prefix(filename, "file:", options); } static QemuOptsList raw_runtime_opts = { .name = "raw", .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head), .desc = { { .name = "filename", .type = QEMU_OPT_STRING, .help = "File name of the image", }, { .name = "aio", .type = QEMU_OPT_STRING, .help = "host AIO implementation (threads, native)", }, { .name = "locking", .type = QEMU_OPT_STRING, .help = "file locking mode (on/off/auto, default: auto)", }, { .name = "pr-manager", .type = QEMU_OPT_STRING, .help = "id of persistent reservation manager object (default: none)", }, #if defined(__linux__) { .name = "drop-cache", .type = QEMU_OPT_BOOL, .help = "invalidate page cache during live migration (default: on)", }, #endif { .name = "x-check-cache-dropped", .type = QEMU_OPT_BOOL, .help = "check that page cache was dropped on live migration (default: off)" }, { /* end of list */ } }, }; static const char *const mutable_opts[] = { "x-check-cache-dropped", NULL }; static int raw_open_common(BlockDriverState *bs, QDict *options, int bdrv_flags, int open_flags, bool device, Error **errp) { BDRVRawState *s = bs->opaque; QemuOpts *opts; Error *local_err = NULL; const char *filename = NULL; const char *str; BlockdevAioOptions aio, aio_default; int fd, ret; struct stat st; OnOffAuto locking; opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort); qemu_opts_absorb_qdict(opts, options, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } filename = qemu_opt_get(opts, "filename"); ret = raw_normalize_devicepath(&filename, errp); if (ret != 0) { goto fail; } aio_default = (bdrv_flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE : BLOCKDEV_AIO_OPTIONS_THREADS; aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"), aio_default, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } s->use_linux_aio = (aio == BLOCKDEV_AIO_OPTIONS_NATIVE); locking = qapi_enum_parse(&OnOffAuto_lookup, qemu_opt_get(opts, "locking"), ON_OFF_AUTO_AUTO, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } switch (locking) { case ON_OFF_AUTO_ON: s->use_lock = true; if (!qemu_has_ofd_lock()) { warn_report("File lock requested but OFD locking syscall is " "unavailable, falling back to POSIX file locks"); error_printf("Due to the implementation, locks can be lost " "unexpectedly.\n"); } break; case ON_OFF_AUTO_OFF: s->use_lock = false; break; case ON_OFF_AUTO_AUTO: s->use_lock = qemu_has_ofd_lock(); break; default: abort(); } str = qemu_opt_get(opts, "pr-manager"); if (str) { s->pr_mgr = pr_manager_lookup(str, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } } s->drop_cache = qemu_opt_get_bool(opts, "drop-cache", true); s->check_cache_dropped = qemu_opt_get_bool(opts, "x-check-cache-dropped", false); s->open_flags = open_flags; raw_parse_flags(bdrv_flags, &s->open_flags, false); s->fd = -1; fd = qemu_open(filename, s->open_flags, 0644); ret = fd < 0 ? -errno : 0; if (ret < 0) { error_setg_file_open(errp, -ret, filename); if (ret == -EROFS) { ret = -EACCES; } goto fail; } s->fd = fd; s->perm = 0; s->shared_perm = BLK_PERM_ALL; #ifdef CONFIG_LINUX_AIO /* Currently Linux does AIO only for files opened with O_DIRECT */ if (s->use_linux_aio) { if (!(s->open_flags & O_DIRECT)) { error_setg(errp, "aio=native was specified, but it requires " "cache.direct=on, which was not specified."); ret = -EINVAL; goto fail; } if (!aio_setup_linux_aio(bdrv_get_aio_context(bs), errp)) { error_prepend(errp, "Unable to use native AIO: "); goto fail; } } #else if (s->use_linux_aio) { error_setg(errp, "aio=native was specified, but is not supported " "in this build."); ret = -EINVAL; goto fail; } #endif /* !defined(CONFIG_LINUX_AIO) */ s->has_discard = true; s->has_write_zeroes = true; if ((bs->open_flags & BDRV_O_NOCACHE) != 0) { s->needs_alignment = true; } if (fstat(s->fd, &st) < 0) { ret = -errno; error_setg_errno(errp, errno, "Could not stat file"); goto fail; } if (!device) { if (S_ISBLK(st.st_mode)) { warn_report("Opening a block device as a file using the '%s' " "driver is deprecated", bs->drv->format_name); } else if (S_ISCHR(st.st_mode)) { warn_report("Opening a character device as a file using the '%s' " "driver is deprecated", bs->drv->format_name); } else if (!S_ISREG(st.st_mode)) { error_setg(errp, "A regular file was expected by the '%s' driver, " "but something else was given", bs->drv->format_name); ret = -EINVAL; goto fail; } else { s->discard_zeroes = true; s->has_fallocate = true; } } else { if (!(S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) { error_setg(errp, "'%s' driver expects either " "a character or block device", bs->drv->format_name); ret = -EINVAL; goto fail; } } if (S_ISBLK(st.st_mode)) { #ifdef BLKDISCARDZEROES unsigned int arg; if (ioctl(s->fd, BLKDISCARDZEROES, &arg) == 0 && arg) { s->discard_zeroes = true; } #endif #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->discard_zeroes = false; s->has_write_zeroes = false; } #endif } #ifdef __FreeBSD__ if (S_ISCHR(st.st_mode)) { /* * The file is a char device (disk), which on FreeBSD isn't behind * a pager, so force all requests to be aligned. This is needed * so QEMU makes sure all IO operations on the device are aligned * to sector size, or else FreeBSD will reject them with EINVAL. */ s->needs_alignment = true; } #endif #ifdef CONFIG_XFS if (platform_test_xfs_fd(s->fd)) { s->is_xfs = true; } #endif bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK; ret = 0; fail: if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) { unlink(filename); } qemu_opts_del(opts); return ret; } static int raw_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVRawState *s = bs->opaque; s->type = FTYPE_FILE; return raw_open_common(bs, options, flags, 0, false, errp); } typedef enum { RAW_PL_PREPARE, RAW_PL_COMMIT, RAW_PL_ABORT, } RawPermLockOp; #define PERM_FOREACH(i) \ for ((i) = 0; (1ULL << (i)) <= BLK_PERM_ALL; i++) /* Lock bytes indicated by @perm_lock_bits and @shared_perm_lock_bits in the * file; if @unlock == true, also unlock the unneeded bytes. * @shared_perm_lock_bits is the mask of all permissions that are NOT shared. */ static int raw_apply_lock_bytes(BDRVRawState *s, int fd, uint64_t perm_lock_bits, uint64_t shared_perm_lock_bits, bool unlock, Error **errp) { int ret; int i; uint64_t locked_perm, locked_shared_perm; if (s) { locked_perm = s->locked_perm; locked_shared_perm = s->locked_shared_perm; } else { /* * We don't have the previous bits, just lock/unlock for each of the * requested bits. */ if (unlock) { locked_perm = BLK_PERM_ALL; locked_shared_perm = BLK_PERM_ALL; } else { locked_perm = 0; locked_shared_perm = 0; } } PERM_FOREACH(i) { int off = RAW_LOCK_PERM_BASE + i; uint64_t bit = (1ULL << i); if ((perm_lock_bits & bit) && !(locked_perm & bit)) { ret = qemu_lock_fd(fd, off, 1, false); if (ret) { error_setg(errp, "Failed to lock byte %d", off); return ret; } else if (s) { s->locked_perm |= bit; } } else if (unlock && (locked_perm & bit) && !(perm_lock_bits & bit)) { ret = qemu_unlock_fd(fd, off, 1); if (ret) { error_setg(errp, "Failed to unlock byte %d", off); return ret; } else if (s) { s->locked_perm &= ~bit; } } } PERM_FOREACH(i) { int off = RAW_LOCK_SHARED_BASE + i; uint64_t bit = (1ULL << i); if ((shared_perm_lock_bits & bit) && !(locked_shared_perm & bit)) { ret = qemu_lock_fd(fd, off, 1, false); if (ret) { error_setg(errp, "Failed to lock byte %d", off); return ret; } else if (s) { s->locked_shared_perm |= bit; } } else if (unlock && (locked_shared_perm & bit) && !(shared_perm_lock_bits & bit)) { ret = qemu_unlock_fd(fd, off, 1); if (ret) { error_setg(errp, "Failed to unlock byte %d", off); return ret; } else if (s) { s->locked_shared_perm &= ~bit; } } } return 0; } /* Check "unshared" bytes implied by @perm and ~@shared_perm in the file. */ static int raw_check_lock_bytes(int fd, uint64_t perm, uint64_t shared_perm, Error **errp) { int ret; int i; PERM_FOREACH(i) { int off = RAW_LOCK_SHARED_BASE + i; uint64_t p = 1ULL << i; if (perm & p) { ret = qemu_lock_fd_test(fd, off, 1, true); if (ret) { char *perm_name = bdrv_perm_names(p); error_setg(errp, "Failed to get \"%s\" lock", perm_name); g_free(perm_name); return ret; } } } PERM_FOREACH(i) { int off = RAW_LOCK_PERM_BASE + i; uint64_t p = 1ULL << i; if (!(shared_perm & p)) { ret = qemu_lock_fd_test(fd, off, 1, true); if (ret) { char *perm_name = bdrv_perm_names(p); error_setg(errp, "Failed to get shared \"%s\" lock", perm_name); g_free(perm_name); return ret; } } } return 0; } static int raw_handle_perm_lock(BlockDriverState *bs, RawPermLockOp op, uint64_t new_perm, uint64_t new_shared, Error **errp) { BDRVRawState *s = bs->opaque; int ret = 0; Error *local_err = NULL; if (!s->use_lock) { return 0; } if (bdrv_get_flags(bs) & BDRV_O_INACTIVE) { return 0; } switch (op) { case RAW_PL_PREPARE: if ((s->perm | new_perm) == s->perm && (s->shared_perm & new_shared) == s->shared_perm) { /* * We are going to unlock bytes, it should not fail. If it fail due * to some fs-dependent permission-unrelated reasons (which occurs * sometimes on NFS and leads to abort in bdrv_replace_child) we * can't prevent such errors by any check here. And we ignore them * anyway in ABORT and COMMIT. */ return 0; } ret = raw_apply_lock_bytes(s, s->fd, s->perm | new_perm, ~s->shared_perm | ~new_shared, false, errp); if (!ret) { ret = raw_check_lock_bytes(s->fd, new_perm, new_shared, errp); if (!ret) { return 0; } error_append_hint(errp, "Is another process using the image [%s]?\n", bs->filename); } op = RAW_PL_ABORT; /* fall through to unlock bytes. */ case RAW_PL_ABORT: raw_apply_lock_bytes(s, s->fd, s->perm, ~s->shared_perm, true, &local_err); if (local_err) { /* Theoretically the above call only unlocks bytes and it cannot * fail. Something weird happened, report it. */ warn_report_err(local_err); } break; case RAW_PL_COMMIT: raw_apply_lock_bytes(s, s->fd, new_perm, ~new_shared, true, &local_err); if (local_err) { /* Theoretically the above call only unlocks bytes and it cannot * fail. Something weird happened, report it. */ warn_report_err(local_err); } break; } return ret; } static int raw_reconfigure_getfd(BlockDriverState *bs, int flags, int *open_flags, uint64_t perm, bool force_dup, Error **errp) { BDRVRawState *s = bs->opaque; int fd = -1; int ret; bool has_writers = perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED | BLK_PERM_RESIZE); int fcntl_flags = O_APPEND | O_NONBLOCK; #ifdef O_NOATIME fcntl_flags |= O_NOATIME; #endif *open_flags = 0; if (s->type == FTYPE_CD) { *open_flags |= O_NONBLOCK; } raw_parse_flags(flags, open_flags, has_writers); #ifdef O_ASYNC /* Not all operating systems have O_ASYNC, and those that don't * will not let us track the state into rs->open_flags (typically * you achieve the same effect with an ioctl, for example I_SETSIG * on Solaris). But we do not use O_ASYNC, so that's fine. */ assert((s->open_flags & O_ASYNC) == 0); #endif if (!force_dup && *open_flags == s->open_flags) { /* We're lucky, the existing fd is fine */ return s->fd; } if ((*open_flags & ~fcntl_flags) == (s->open_flags & ~fcntl_flags)) { /* dup the original fd */ fd = qemu_dup(s->fd); if (fd >= 0) { ret = fcntl_setfl(fd, *open_flags); if (ret) { qemu_close(fd); fd = -1; } } } /* If we cannot use fcntl, or fcntl failed, fall back to qemu_open() */ if (fd == -1) { const char *normalized_filename = bs->filename; ret = raw_normalize_devicepath(&normalized_filename, errp); if (ret >= 0) { assert(!(*open_flags & O_CREAT)); fd = qemu_open(normalized_filename, *open_flags); if (fd == -1) { error_setg_errno(errp, errno, "Could not reopen file"); return -1; } } } return fd; } static int raw_reopen_prepare(BDRVReopenState *state, BlockReopenQueue *queue, Error **errp) { BDRVRawState *s; BDRVRawReopenState *rs; QemuOpts *opts; int ret; Error *local_err = NULL; assert(state != NULL); assert(state->bs != NULL); s = state->bs->opaque; state->opaque = g_new0(BDRVRawReopenState, 1); rs = state->opaque; /* Handle options changes */ opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort); qemu_opts_absorb_qdict(opts, state->options, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto out; } rs->drop_cache = qemu_opt_get_bool_del(opts, "drop-cache", true); rs->check_cache_dropped = qemu_opt_get_bool_del(opts, "x-check-cache-dropped", false); /* This driver's reopen function doesn't currently allow changing * other options, so let's put them back in the original QDict and * bdrv_reopen_prepare() will detect changes and complain. */ qemu_opts_to_qdict(opts, state->options); rs->fd = raw_reconfigure_getfd(state->bs, state->flags, &rs->open_flags, state->perm, true, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -1; goto out; } /* Fail already reopen_prepare() if we can't get a working O_DIRECT * alignment with the new fd. */ if (rs->fd != -1) { raw_probe_alignment(state->bs, rs->fd, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto out_fd; } } s->reopen_state = state; ret = 0; out_fd: if (ret < 0) { qemu_close(rs->fd); rs->fd = -1; } out: qemu_opts_del(opts); return ret; } static void raw_reopen_commit(BDRVReopenState *state) { BDRVRawReopenState *rs = state->opaque; BDRVRawState *s = state->bs->opaque; s->drop_cache = rs->drop_cache; s->check_cache_dropped = rs->check_cache_dropped; s->open_flags = rs->open_flags; qemu_close(s->fd); s->fd = rs->fd; g_free(state->opaque); state->opaque = NULL; assert(s->reopen_state == state); s->reopen_state = NULL; } static void raw_reopen_abort(BDRVReopenState *state) { BDRVRawReopenState *rs = state->opaque; BDRVRawState *s = state->bs->opaque; /* nothing to do if NULL, we didn't get far enough */ if (rs == NULL) { return; } if (rs->fd >= 0) { qemu_close(rs->fd); rs->fd = -1; } g_free(state->opaque); state->opaque = NULL; assert(s->reopen_state == state); s->reopen_state = NULL; } static int sg_get_max_transfer_length(int fd) { #ifdef BLKSECTGET int max_bytes = 0; if (ioctl(fd, BLKSECTGET, &max_bytes) == 0) { return max_bytes; } else { return -errno; } #else return -ENOSYS; #endif } static int sg_get_max_segments(int fd) { #ifdef CONFIG_LINUX char buf[32]; const char *end; char *sysfspath = NULL; int ret; int sysfd = -1; long max_segments; struct stat st; if (fstat(fd, &st)) { ret = -errno; goto out; } sysfspath = g_strdup_printf("/sys/dev/block/%u:%u/queue/max_segments", major(st.st_rdev), minor(st.st_rdev)); sysfd = open(sysfspath, O_RDONLY); if (sysfd == -1) { ret = -errno; goto out; } do { ret = read(sysfd, buf, sizeof(buf) - 1); } while (ret == -1 && errno == EINTR); if (ret < 0) { ret = -errno; goto out; } else if (ret == 0) { ret = -EIO; goto out; } buf[ret] = 0; /* The file is ended with '\n', pass 'end' to accept that. */ ret = qemu_strtol(buf, &end, 10, &max_segments); if (ret == 0 && end && *end == '\n') { ret = max_segments; } out: if (sysfd != -1) { close(sysfd); } g_free(sysfspath); return ret; #else return -ENOTSUP; #endif } static void raw_refresh_limits(BlockDriverState *bs, Error **errp) { BDRVRawState *s = bs->opaque; if (bs->sg) { int ret = sg_get_max_transfer_length(s->fd); if (ret > 0 && ret <= BDRV_REQUEST_MAX_BYTES) { bs->bl.max_transfer = pow2floor(ret); } ret = sg_get_max_segments(s->fd); if (ret > 0) { bs->bl.max_transfer = MIN(bs->bl.max_transfer, ret * getpagesize()); } } raw_probe_alignment(bs, s->fd, errp); bs->bl.min_mem_alignment = s->buf_align; bs->bl.opt_mem_alignment = MAX(s->buf_align, getpagesize()); } static int check_for_dasd(int fd) { #ifdef BIODASDINFO2 struct dasd_information2_t info = {0}; return ioctl(fd, BIODASDINFO2, &info); #else return -1; #endif } /** * Try to get @bs's logical and physical block size. * On success, store them in @bsz and return zero. * On failure, return negative errno. */ static int hdev_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) { BDRVRawState *s = bs->opaque; int ret; /* If DASD, get blocksizes */ if (check_for_dasd(s->fd) < 0) { return -ENOTSUP; } ret = probe_logical_blocksize(s->fd, &bsz->log); if (ret < 0) { return ret; } return probe_physical_blocksize(s->fd, &bsz->phys); } /** * Try to get @bs's geometry: cyls, heads, sectors. * On success, store them in @geo and return 0. * On failure return -errno. * (Allows block driver to assign default geometry values that guest sees) */ #ifdef __linux__ static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo) { BDRVRawState *s = bs->opaque; struct hd_geometry ioctl_geo = {0}; /* If DASD, get its geometry */ if (check_for_dasd(s->fd) < 0) { return -ENOTSUP; } if (ioctl(s->fd, HDIO_GETGEO, &ioctl_geo) < 0) { return -errno; } /* HDIO_GETGEO may return success even though geo contains zeros (e.g. certain multipath setups) */ if (!ioctl_geo.heads || !ioctl_geo.sectors || !ioctl_geo.cylinders) { return -ENOTSUP; } /* Do not return a geometry for partition */ if (ioctl_geo.start != 0) { return -ENOTSUP; } geo->heads = ioctl_geo.heads; geo->sectors = ioctl_geo.sectors; geo->cylinders = ioctl_geo.cylinders; return 0; } #else /* __linux__ */ static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo) { return -ENOTSUP; } #endif #if defined(__linux__) static int handle_aiocb_ioctl(void *opaque) { RawPosixAIOData *aiocb = opaque; int ret; ret = ioctl(aiocb->aio_fildes, aiocb->ioctl.cmd, aiocb->ioctl.buf); if (ret == -1) { return -errno; } return 0; } #endif /* linux */ static int handle_aiocb_flush(void *opaque) { RawPosixAIOData *aiocb = opaque; BDRVRawState *s = aiocb->bs->opaque; int ret; if (s->page_cache_inconsistent) { return -EIO; } ret = qemu_fdatasync(aiocb->aio_fildes); if (ret == -1) { /* There is no clear definition of the semantics of a failing fsync(), * so we may have to assume the worst. The sad truth is that this * assumption is correct for Linux. Some pages are now probably marked * clean in the page cache even though they are inconsistent with the * on-disk contents. The next fdatasync() call would succeed, but no * further writeback attempt will be made. We can't get back to a state * in which we know what is on disk (we would have to rewrite * everything that was touched since the last fdatasync() at least), so * make bdrv_flush() fail permanently. Given that the behaviour isn't * really defined, I have little hope that other OSes are doing better. * * Obviously, this doesn't affect O_DIRECT, which bypasses the page * cache. */ if ((s->open_flags & O_DIRECT) == 0) { s->page_cache_inconsistent = true; } return -errno; } return 0; } #ifdef CONFIG_PREADV static bool preadv_present = true; static ssize_t qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset) { return preadv(fd, iov, nr_iov, offset); } static ssize_t qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset) { return pwritev(fd, iov, nr_iov, offset); } #else static bool preadv_present = false; static ssize_t qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset) { return -ENOSYS; } static ssize_t qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset) { return -ENOSYS; } #endif static ssize_t handle_aiocb_rw_vector(RawPosixAIOData *aiocb) { ssize_t len; do { if (aiocb->aio_type & QEMU_AIO_WRITE) len = qemu_pwritev(aiocb->aio_fildes, aiocb->io.iov, aiocb->io.niov, aiocb->aio_offset); else len = qemu_preadv(aiocb->aio_fildes, aiocb->io.iov, aiocb->io.niov, aiocb->aio_offset); } while (len == -1 && errno == EINTR); if (len == -1) { return -errno; } return len; } /* * Read/writes the data to/from a given linear buffer. * * Returns the number of bytes handles or -errno in case of an error. Short * reads are only returned if the end of the file is reached. */ static ssize_t handle_aiocb_rw_linear(RawPosixAIOData *aiocb, char *buf) { ssize_t offset = 0; ssize_t len; while (offset < aiocb->aio_nbytes) { if (aiocb->aio_type & QEMU_AIO_WRITE) { len = pwrite(aiocb->aio_fildes, (const char *)buf + offset, aiocb->aio_nbytes - offset, aiocb->aio_offset + offset); } else { len = pread(aiocb->aio_fildes, buf + offset, aiocb->aio_nbytes - offset, aiocb->aio_offset + offset); } if (len == -1 && errno == EINTR) { continue; } else if (len == -1 && errno == EINVAL && (aiocb->bs->open_flags & BDRV_O_NOCACHE) && !(aiocb->aio_type & QEMU_AIO_WRITE) && offset > 0) { /* O_DIRECT pread() may fail with EINVAL when offset is unaligned * after a short read. Assume that O_DIRECT short reads only occur * at EOF. Therefore this is a short read, not an I/O error. */ break; } else if (len == -1) { offset = -errno; break; } else if (len == 0) { break; } offset += len; } return offset; } static int handle_aiocb_rw(void *opaque) { RawPosixAIOData *aiocb = opaque; ssize_t nbytes; char *buf; if (!(aiocb->aio_type & QEMU_AIO_MISALIGNED)) { /* * If there is just a single buffer, and it is properly aligned * we can just use plain pread/pwrite without any problems. */ if (aiocb->io.niov == 1) { nbytes = handle_aiocb_rw_linear(aiocb, aiocb->io.iov->iov_base); goto out; } /* * We have more than one iovec, and all are properly aligned. * * Try preadv/pwritev first and fall back to linearizing the * buffer if it's not supported. */ if (preadv_present) { nbytes = handle_aiocb_rw_vector(aiocb); if (nbytes == aiocb->aio_nbytes || (nbytes < 0 && nbytes != -ENOSYS)) { goto out; } preadv_present = false; } /* * XXX(hch): short read/write. no easy way to handle the reminder * using these interfaces. For now retry using plain * pread/pwrite? */ } /* * Ok, we have to do it the hard way, copy all segments into * a single aligned buffer. */ buf = qemu_try_blockalign(aiocb->bs, aiocb->aio_nbytes); if (buf == NULL) { nbytes = -ENOMEM; goto out; } if (aiocb->aio_type & QEMU_AIO_WRITE) { char *p = buf; int i; for (i = 0; i < aiocb->io.niov; ++i) { memcpy(p, aiocb->io.iov[i].iov_base, aiocb->io.iov[i].iov_len); p += aiocb->io.iov[i].iov_len; } assert(p - buf == aiocb->aio_nbytes); } nbytes = handle_aiocb_rw_linear(aiocb, buf); if (!(aiocb->aio_type & QEMU_AIO_WRITE)) { char *p = buf; size_t count = aiocb->aio_nbytes, copy; int i; for (i = 0; i < aiocb->io.niov && count; ++i) { copy = count; if (copy > aiocb->io.iov[i].iov_len) { copy = aiocb->io.iov[i].iov_len; } memcpy(aiocb->io.iov[i].iov_base, p, copy); assert(count >= copy); p += copy; count -= copy; } assert(count == 0); } qemu_vfree(buf); out: if (nbytes == aiocb->aio_nbytes) { return 0; } else if (nbytes >= 0 && nbytes < aiocb->aio_nbytes) { if (aiocb->aio_type & QEMU_AIO_WRITE) { return -EINVAL; } else { iov_memset(aiocb->io.iov, aiocb->io.niov, nbytes, 0, aiocb->aio_nbytes - nbytes); return 0; } } else { assert(nbytes < 0); return nbytes; } } #ifdef CONFIG_XFS static int xfs_write_zeroes(BDRVRawState *s, int64_t offset, uint64_t bytes) { int64_t len; struct xfs_flock64 fl; int err; len = lseek(s->fd, 0, SEEK_END); if (len < 0) { return -errno; } if (offset + bytes > len) { /* XFS_IOC_ZERO_RANGE does not increase the file length */ if (ftruncate(s->fd, offset + bytes) < 0) { return -errno; } } memset(&fl, 0, sizeof(fl)); fl.l_whence = SEEK_SET; fl.l_start = offset; fl.l_len = bytes; if (xfsctl(NULL, s->fd, XFS_IOC_ZERO_RANGE, &fl) < 0) { err = errno; trace_file_xfs_write_zeroes(strerror(errno)); return -err; } return 0; } static int xfs_discard(BDRVRawState *s, int64_t offset, uint64_t bytes) { struct xfs_flock64 fl; int err; memset(&fl, 0, sizeof(fl)); fl.l_whence = SEEK_SET; fl.l_start = offset; fl.l_len = bytes; if (xfsctl(NULL, s->fd, XFS_IOC_UNRESVSP64, &fl) < 0) { err = errno; trace_file_xfs_discard(strerror(errno)); return -err; } return 0; } #endif static int translate_err(int err) { if (err == -ENODEV || err == -ENOSYS || err == -EOPNOTSUPP || err == -ENOTTY) { err = -ENOTSUP; } return err; } #ifdef CONFIG_FALLOCATE static int do_fallocate(int fd, int mode, off_t offset, off_t len) { do { if (fallocate(fd, mode, offset, len) == 0) { return 0; } } while (errno == EINTR); return translate_err(-errno); } #endif static ssize_t handle_aiocb_write_zeroes_block(RawPosixAIOData *aiocb) { int ret = -ENOTSUP; BDRVRawState *s = aiocb->bs->opaque; if (!s->has_write_zeroes) { return -ENOTSUP; } #ifdef BLKZEROOUT /* The BLKZEROOUT implementation in the kernel doesn't set * BLKDEV_ZERO_NOFALLBACK, so we can't call this if we have to avoid slow * fallbacks. */ if (!(aiocb->aio_type & QEMU_AIO_NO_FALLBACK)) { do { uint64_t range[2] = { aiocb->aio_offset, aiocb->aio_nbytes }; if (ioctl(aiocb->aio_fildes, BLKZEROOUT, range) == 0) { return 0; } } while (errno == EINTR); ret = translate_err(-errno); } #endif if (ret == -ENOTSUP) { s->has_write_zeroes = false; } return ret; } static int handle_aiocb_write_zeroes(void *opaque) { RawPosixAIOData *aiocb = opaque; #if defined(CONFIG_FALLOCATE) || defined(CONFIG_XFS) BDRVRawState *s = aiocb->bs->opaque; #endif #ifdef CONFIG_FALLOCATE int64_t len; #endif if (aiocb->aio_type & QEMU_AIO_BLKDEV) { return handle_aiocb_write_zeroes_block(aiocb); } #ifdef CONFIG_XFS if (s->is_xfs) { return xfs_write_zeroes(s, aiocb->aio_offset, aiocb->aio_nbytes); } #endif #ifdef CONFIG_FALLOCATE_ZERO_RANGE if (s->has_write_zeroes) { int ret = do_fallocate(s->fd, FALLOC_FL_ZERO_RANGE, aiocb->aio_offset, aiocb->aio_nbytes); if (ret == 0 || ret != -ENOTSUP) { return ret; } s->has_write_zeroes = false; } #endif #ifdef CONFIG_FALLOCATE_PUNCH_HOLE if (s->has_discard && s->has_fallocate) { int ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, aiocb->aio_offset, aiocb->aio_nbytes); if (ret == 0) { ret = do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes); if (ret == 0 || ret != -ENOTSUP) { return ret; } s->has_fallocate = false; } else if (ret != -ENOTSUP) { return ret; } else { s->has_discard = false; } } #endif #ifdef CONFIG_FALLOCATE /* Last resort: we are trying to extend the file with zeroed data. This * can be done via fallocate(fd, 0) */ len = bdrv_getlength(aiocb->bs); if (s->has_fallocate && len >= 0 && aiocb->aio_offset >= len) { int ret = do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes); if (ret == 0 || ret != -ENOTSUP) { return ret; } s->has_fallocate = false; } #endif return -ENOTSUP; } static int handle_aiocb_write_zeroes_unmap(void *opaque) { RawPosixAIOData *aiocb = opaque; BDRVRawState *s G_GNUC_UNUSED = aiocb->bs->opaque; int ret; /* First try to write zeros and unmap at the same time */ #ifdef CONFIG_FALLOCATE_PUNCH_HOLE ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, aiocb->aio_offset, aiocb->aio_nbytes); if (ret != -ENOTSUP) { return ret; } #endif #ifdef CONFIG_XFS if (s->is_xfs) { /* xfs_discard() guarantees that the discarded area reads as all-zero * afterwards, so we can use it here. */ return xfs_discard(s, aiocb->aio_offset, aiocb->aio_nbytes); } #endif /* If we couldn't manage to unmap while guaranteed that the area reads as * all-zero afterwards, just write zeroes without unmapping */ ret = handle_aiocb_write_zeroes(aiocb); return ret; } #ifndef HAVE_COPY_FILE_RANGE static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd, off_t *out_off, size_t len, unsigned int flags) { #ifdef __NR_copy_file_range return syscall(__NR_copy_file_range, in_fd, in_off, out_fd, out_off, len, flags); #else errno = ENOSYS; return -1; #endif } #endif static int handle_aiocb_copy_range(void *opaque) { RawPosixAIOData *aiocb = opaque; uint64_t bytes = aiocb->aio_nbytes; off_t in_off = aiocb->aio_offset; off_t out_off = aiocb->copy_range.aio_offset2; while (bytes) { ssize_t ret = copy_file_range(aiocb->aio_fildes, &in_off, aiocb->copy_range.aio_fd2, &out_off, bytes, 0); trace_file_copy_file_range(aiocb->bs, aiocb->aio_fildes, in_off, aiocb->copy_range.aio_fd2, out_off, bytes, 0, ret); if (ret == 0) { /* No progress (e.g. when beyond EOF), let the caller fall back to * buffer I/O. */ return -ENOSPC; } if (ret < 0) { switch (errno) { case ENOSYS: return -ENOTSUP; case EINTR: continue; default: return -errno; } } bytes -= ret; } return 0; } static int handle_aiocb_discard(void *opaque) { RawPosixAIOData *aiocb = opaque; int ret = -EOPNOTSUPP; BDRVRawState *s = aiocb->bs->opaque; if (!s->has_discard) { return -ENOTSUP; } if (aiocb->aio_type & QEMU_AIO_BLKDEV) { #ifdef BLKDISCARD do { uint64_t range[2] = { aiocb->aio_offset, aiocb->aio_nbytes }; if (ioctl(aiocb->aio_fildes, BLKDISCARD, range) == 0) { return 0; } } while (errno == EINTR); ret = -errno; #endif } else { #ifdef CONFIG_XFS if (s->is_xfs) { return xfs_discard(s, aiocb->aio_offset, aiocb->aio_nbytes); } #endif #ifdef CONFIG_FALLOCATE_PUNCH_HOLE ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, aiocb->aio_offset, aiocb->aio_nbytes); #endif } ret = translate_err(ret); if (ret == -ENOTSUP) { s->has_discard = false; } return ret; } static int handle_aiocb_truncate(void *opaque) { RawPosixAIOData *aiocb = opaque; int result = 0; int64_t current_length = 0; char *buf = NULL; struct stat st; int fd = aiocb->aio_fildes; int64_t offset = aiocb->aio_offset; PreallocMode prealloc = aiocb->truncate.prealloc; Error **errp = aiocb->truncate.errp; if (fstat(fd, &st) < 0) { result = -errno; error_setg_errno(errp, -result, "Could not stat file"); return result; } current_length = st.st_size; if (current_length > offset && prealloc != PREALLOC_MODE_OFF) { error_setg(errp, "Cannot use preallocation for shrinking files"); return -ENOTSUP; } switch (prealloc) { #ifdef CONFIG_POSIX_FALLOCATE case PREALLOC_MODE_FALLOC: /* * Truncating before posix_fallocate() makes it about twice slower on * file systems that do not support fallocate(), trying to check if a * block is allocated before allocating it, so don't do that here. */ if (offset != current_length) { result = -posix_fallocate(fd, current_length, offset - current_length); if (result != 0) { /* posix_fallocate() doesn't set errno. */ error_setg_errno(errp, -result, "Could not preallocate new data"); } } else { result = 0; } goto out; #endif case PREALLOC_MODE_FULL: { int64_t num = 0, left = offset - current_length; off_t seek_result; /* * Knowing the final size from the beginning could allow the file * system driver to do less allocations and possibly avoid * fragmentation of the file. */ if (ftruncate(fd, offset) != 0) { result = -errno; error_setg_errno(errp, -result, "Could not resize file"); goto out; } buf = g_malloc0(65536); seek_result = lseek(fd, current_length, SEEK_SET); if (seek_result < 0) { result = -errno; error_setg_errno(errp, -result, "Failed to seek to the old end of file"); goto out; } while (left > 0) { num = MIN(left, 65536); result = write(fd, buf, num); if (result < 0) { if (errno == EINTR) { continue; } result = -errno; error_setg_errno(errp, -result, "Could not write zeros for preallocation"); goto out; } left -= result; } if (result >= 0) { result = fsync(fd); if (result < 0) { result = -errno; error_setg_errno(errp, -result, "Could not flush file to disk"); goto out; } } goto out; } case PREALLOC_MODE_OFF: if (ftruncate(fd, offset) != 0) { result = -errno; error_setg_errno(errp, -result, "Could not resize file"); } return result; default: result = -ENOTSUP; error_setg(errp, "Unsupported preallocation mode: %s", PreallocMode_str(prealloc)); return result; } out: if (result < 0) { if (ftruncate(fd, current_length) < 0) { error_report("Failed to restore old file length: %s", strerror(errno)); } } g_free(buf); return result; } static int coroutine_fn raw_thread_pool_submit(BlockDriverState *bs, ThreadPoolFunc func, void *arg) { /* @bs can be NULL, bdrv_get_aio_context() returns the main context then */ ThreadPool *pool = aio_get_thread_pool(bdrv_get_aio_context(bs)); return thread_pool_submit_co(pool, func, arg); } static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int type) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; if (fd_open(bs) < 0) return -EIO; /* * Check if the underlying device requires requests to be aligned, * and if the request we are trying to submit is aligned or not. * If this is the case tell the low-level driver that it needs * to copy the buffer. */ if (s->needs_alignment) { if (!bdrv_qiov_is_aligned(bs, qiov)) { type |= QEMU_AIO_MISALIGNED; #ifdef CONFIG_LINUX_AIO } else if (s->use_linux_aio) { LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs)); assert(qiov->size == bytes); return laio_co_submit(bs, aio, s->fd, offset, qiov, type); #endif } } acb = (RawPosixAIOData) { .bs = bs, .aio_fildes = s->fd, .aio_type = type, .aio_offset = offset, .aio_nbytes = bytes, .io = { .iov = qiov->iov, .niov = qiov->niov, }, }; assert(qiov->size == bytes); return raw_thread_pool_submit(bs, handle_aiocb_rw, &acb); } static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_READ); } static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { assert(flags == 0); return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_WRITE); } static void raw_aio_plug(BlockDriverState *bs) { #ifdef CONFIG_LINUX_AIO BDRVRawState *s = bs->opaque; if (s->use_linux_aio) { LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs)); laio_io_plug(bs, aio); } #endif } static void raw_aio_unplug(BlockDriverState *bs) { #ifdef CONFIG_LINUX_AIO BDRVRawState *s = bs->opaque; if (s->use_linux_aio) { LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs)); laio_io_unplug(bs, aio); } #endif } static int raw_co_flush_to_disk(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; int ret; ret = fd_open(bs); if (ret < 0) { return ret; } acb = (RawPosixAIOData) { .bs = bs, .aio_fildes = s->fd, .aio_type = QEMU_AIO_FLUSH, }; return raw_thread_pool_submit(bs, handle_aiocb_flush, &acb); } static void raw_aio_attach_aio_context(BlockDriverState *bs, AioContext *new_context) { #ifdef CONFIG_LINUX_AIO BDRVRawState *s = bs->opaque; if (s->use_linux_aio) { Error *local_err; if (!aio_setup_linux_aio(new_context, &local_err)) { error_reportf_err(local_err, "Unable to use native AIO, " "falling back to thread pool: "); s->use_linux_aio = false; } } #endif } static void raw_close(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; if (s->fd >= 0) { qemu_close(s->fd); s->fd = -1; } } /** * Truncates the given regular file @fd to @offset and, when growing, fills the * new space according to @prealloc. * * Returns: 0 on success, -errno on failure. */ static int coroutine_fn raw_regular_truncate(BlockDriverState *bs, int fd, int64_t offset, PreallocMode prealloc, Error **errp) { RawPosixAIOData acb; acb = (RawPosixAIOData) { .bs = bs, .aio_fildes = fd, .aio_type = QEMU_AIO_TRUNCATE, .aio_offset = offset, .truncate = { .prealloc = prealloc, .errp = errp, }, }; return raw_thread_pool_submit(bs, handle_aiocb_truncate, &acb); } static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, PreallocMode prealloc, Error **errp) { BDRVRawState *s = bs->opaque; struct stat st; int ret; if (fstat(s->fd, &st)) { ret = -errno; error_setg_errno(errp, -ret, "Failed to fstat() the file"); return ret; } if (S_ISREG(st.st_mode)) { return raw_regular_truncate(bs, s->fd, offset, prealloc, errp); } if (prealloc != PREALLOC_MODE_OFF) { error_setg(errp, "Preallocation mode '%s' unsupported for this " "non-regular file", PreallocMode_str(prealloc)); return -ENOTSUP; } if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { if (offset > raw_getlength(bs)) { error_setg(errp, "Cannot grow device files"); return -EINVAL; } } else { error_setg(errp, "Resizing this file is not supported"); return -ENOTSUP; } return 0; } #ifdef __OpenBSD__ static int64_t raw_getlength(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; int fd = s->fd; struct stat st; if (fstat(fd, &st)) return -errno; if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { struct disklabel dl; if (ioctl(fd, DIOCGDINFO, &dl)) return -errno; return (uint64_t)dl.d_secsize * dl.d_partitions[DISKPART(st.st_rdev)].p_size; } else return st.st_size; } #elif defined(__NetBSD__) static int64_t raw_getlength(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; int fd = s->fd; struct stat st; if (fstat(fd, &st)) return -errno; if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { struct dkwedge_info dkw; if (ioctl(fd, DIOCGWEDGEINFO, &dkw) != -1) { return dkw.dkw_size * 512; } else { struct disklabel dl; if (ioctl(fd, DIOCGDINFO, &dl)) return -errno; return (uint64_t)dl.d_secsize * dl.d_partitions[DISKPART(st.st_rdev)].p_size; } } else return st.st_size; } #elif defined(__sun__) static int64_t raw_getlength(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; struct dk_minfo minfo; int ret; int64_t size; ret = fd_open(bs); if (ret < 0) { return ret; } /* * Use the DKIOCGMEDIAINFO ioctl to read the size. */ ret = ioctl(s->fd, DKIOCGMEDIAINFO, &minfo); if (ret != -1) { return minfo.dki_lbsize * minfo.dki_capacity; } /* * There are reports that lseek on some devices fails, but * irc discussion said that contingency on contingency was overkill. */ size = lseek(s->fd, 0, SEEK_END); if (size < 0) { return -errno; } return size; } #elif defined(CONFIG_BSD) static int64_t raw_getlength(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; int fd = s->fd; int64_t size; struct stat sb; #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) int reopened = 0; #endif int ret; ret = fd_open(bs); if (ret < 0) return ret; #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) again: #endif if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) { #ifdef DIOCGMEDIASIZE if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size)) #elif defined(DIOCGPART) { struct partinfo pi; if (ioctl(fd, DIOCGPART, &pi) == 0) size = pi.media_size; else size = 0; } if (size == 0) #endif #if defined(__APPLE__) && defined(__MACH__) { uint64_t sectors = 0; uint32_t sector_size = 0; if (ioctl(fd, DKIOCGETBLOCKCOUNT, §ors) == 0 && ioctl(fd, DKIOCGETBLOCKSIZE, §or_size) == 0) { size = sectors * sector_size; } else { size = lseek(fd, 0LL, SEEK_END); if (size < 0) { return -errno; } } } #else size = lseek(fd, 0LL, SEEK_END); if (size < 0) { return -errno; } #endif #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) switch(s->type) { case FTYPE_CD: /* XXX FreeBSD acd returns UINT_MAX sectors for an empty drive */ if (size == 2048LL * (unsigned)-1) size = 0; /* XXX no disc? maybe we need to reopen... */ if (size <= 0 && !reopened && cdrom_reopen(bs) >= 0) { reopened = 1; goto again; } } #endif } else { size = lseek(fd, 0, SEEK_END); if (size < 0) { return -errno; } } return size; } #else static int64_t raw_getlength(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; int ret; int64_t size; ret = fd_open(bs); if (ret < 0) { return ret; } size = lseek(s->fd, 0, SEEK_END); if (size < 0) { return -errno; } return size; } #endif static int64_t raw_get_allocated_file_size(BlockDriverState *bs) { struct stat st; BDRVRawState *s = bs->opaque; if (fstat(s->fd, &st) < 0) { return -errno; } return (int64_t)st.st_blocks * 512; } static int coroutine_fn raw_co_create(BlockdevCreateOptions *options, Error **errp) { BlockdevCreateOptionsFile *file_opts; Error *local_err = NULL; int fd; uint64_t perm, shared; int result = 0; /* Validate options and set default values */ assert(options->driver == BLOCKDEV_DRIVER_FILE); file_opts = &options->u.file; if (!file_opts->has_nocow) { file_opts->nocow = false; } if (!file_opts->has_preallocation) { file_opts->preallocation = PREALLOC_MODE_OFF; } /* Create file */ fd = qemu_open(file_opts->filename, O_RDWR | O_CREAT | O_BINARY, 0644); if (fd < 0) { result = -errno; error_setg_errno(errp, -result, "Could not create file"); goto out; } /* Take permissions: We want to discard everything, so we need * BLK_PERM_WRITE; and truncation to the desired size requires * BLK_PERM_RESIZE. * On the other hand, we cannot share the RESIZE permission * because we promise that after this function, the file has the * size given in the options. If someone else were to resize it * concurrently, we could not guarantee that. * Note that after this function, we can no longer guarantee that * the file is not touched by a third party, so it may be resized * then. */ perm = BLK_PERM_WRITE | BLK_PERM_RESIZE; shared = BLK_PERM_ALL & ~BLK_PERM_RESIZE; /* Step one: Take locks */ result = raw_apply_lock_bytes(NULL, fd, perm, ~shared, false, errp); if (result < 0) { goto out_close; } /* Step two: Check that nobody else has taken conflicting locks */ result = raw_check_lock_bytes(fd, perm, shared, errp); if (result < 0) { error_append_hint(errp, "Is another process using the image [%s]?\n", file_opts->filename); goto out_unlock; } /* Clear the file by truncating it to 0 */ result = raw_regular_truncate(NULL, fd, 0, PREALLOC_MODE_OFF, errp); if (result < 0) { goto out_unlock; } if (file_opts->nocow) { #ifdef __linux__ /* Set NOCOW flag to solve performance issue on fs like btrfs. * This is an optimisation. The FS_IOC_SETFLAGS ioctl return value * will be ignored since any failure of this operation should not * block the left work. */ int attr; if (ioctl(fd, FS_IOC_GETFLAGS, &attr) == 0) { attr |= FS_NOCOW_FL; ioctl(fd, FS_IOC_SETFLAGS, &attr); } #endif } /* Resize and potentially preallocate the file to the desired * final size */ result = raw_regular_truncate(NULL, fd, file_opts->size, file_opts->preallocation, errp); if (result < 0) { goto out_unlock; } out_unlock: raw_apply_lock_bytes(NULL, fd, 0, 0, true, &local_err); if (local_err) { /* The above call should not fail, and if it does, that does * not mean the whole creation operation has failed. So * report it the user for their convenience, but do not report * it to the caller. */ warn_report_err(local_err); } out_close: if (qemu_close(fd) != 0 && result == 0) { result = -errno; error_setg_errno(errp, -result, "Could not close the new file"); } out: return result; } static int coroutine_fn raw_co_create_opts(const char *filename, QemuOpts *opts, Error **errp) { BlockdevCreateOptions options; int64_t total_size = 0; bool nocow = false; PreallocMode prealloc; char *buf = NULL; Error *local_err = NULL; /* Skip file: protocol prefix */ strstart(filename, "file:", &filename); /* Read out options */ total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), BDRV_SECTOR_SIZE); nocow = qemu_opt_get_bool(opts, BLOCK_OPT_NOCOW, false); buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); prealloc = qapi_enum_parse(&PreallocMode_lookup, buf, PREALLOC_MODE_OFF, &local_err); g_free(buf); if (local_err) { error_propagate(errp, local_err); return -EINVAL; } options = (BlockdevCreateOptions) { .driver = BLOCKDEV_DRIVER_FILE, .u.file = { .filename = (char *) filename, .size = total_size, .has_preallocation = true, .preallocation = prealloc, .has_nocow = true, .nocow = nocow, }, }; return raw_co_create(&options, errp); } /* * Find allocation range in @bs around offset @start. * May change underlying file descriptor's file offset. * If @start is not in a hole, store @start in @data, and the * beginning of the next hole in @hole, and return 0. * If @start is in a non-trailing hole, store @start in @hole and the * beginning of the next non-hole in @data, and return 0. * If @start is in a trailing hole or beyond EOF, return -ENXIO. * If we can't find out, return a negative errno other than -ENXIO. */ static int find_allocation(BlockDriverState *bs, off_t start, off_t *data, off_t *hole) { #if defined SEEK_HOLE && defined SEEK_DATA BDRVRawState *s = bs->opaque; off_t offs; /* * SEEK_DATA cases: * D1. offs == start: start is in data * D2. offs > start: start is in a hole, next data at offs * D3. offs < 0, errno = ENXIO: either start is in a trailing hole * or start is beyond EOF * If the latter happens, the file has been truncated behind * our back since we opened it. All bets are off then. * Treating like a trailing hole is simplest. * D4. offs < 0, errno != ENXIO: we learned nothing */ offs = lseek(s->fd, start, SEEK_DATA); if (offs < 0) { return -errno; /* D3 or D4 */ } if (offs < start) { /* This is not a valid return by lseek(). We are safe to just return * -EIO in this case, and we'll treat it like D4. */ return -EIO; } if (offs > start) { /* D2: in hole, next data at offs */ *hole = start; *data = offs; return 0; } /* D1: in data, end not yet known */ /* * SEEK_HOLE cases: * H1. offs == start: start is in a hole * If this happens here, a hole has been dug behind our back * since the previous lseek(). * H2. offs > start: either start is in data, next hole at offs, * or start is in trailing hole, EOF at offs * Linux treats trailing holes like any other hole: offs == * start. Solaris seeks to EOF instead: offs > start (blech). * If that happens here, a hole has been dug behind our back * since the previous lseek(). * H3. offs < 0, errno = ENXIO: start is beyond EOF * If this happens, the file has been truncated behind our * back since we opened it. Treat it like a trailing hole. * H4. offs < 0, errno != ENXIO: we learned nothing * Pretend we know nothing at all, i.e. "forget" about D1. */ offs = lseek(s->fd, start, SEEK_HOLE); if (offs < 0) { return -errno; /* D1 and (H3 or H4) */ } if (offs < start) { /* This is not a valid return by lseek(). We are safe to just return * -EIO in this case, and we'll treat it like H4. */ return -EIO; } if (offs > start) { /* * D1 and H2: either in data, next hole at offs, or it was in * data but is now in a trailing hole. In the latter case, * all bets are off. Treating it as if it there was data all * the way to EOF is safe, so simply do that. */ *data = start; *hole = offs; return 0; } /* D1 and H1 */ return -EBUSY; #else return -ENOTSUP; #endif } /* * Returns the allocation status of the specified offset. * * The block layer guarantees 'offset' and 'bytes' are within bounds. * * 'pnum' is set to the number of bytes (including and immediately following * the specified offset) that are known to be in the same * allocated/unallocated state. * * 'bytes' is the max value 'pnum' should be set to. */ static int coroutine_fn raw_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file) { off_t data = 0, hole = 0; int ret; assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment)); ret = fd_open(bs); if (ret < 0) { return ret; } if (!want_zero) { *pnum = bytes; *map = offset; *file = bs; return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; } ret = find_allocation(bs, offset, &data, &hole); if (ret == -ENXIO) { /* Trailing hole */ *pnum = bytes; ret = BDRV_BLOCK_ZERO; } else if (ret < 0) { /* No info available, so pretend there are no holes */ *pnum = bytes; ret = BDRV_BLOCK_DATA; } else if (data == offset) { /* On a data extent, compute bytes to the end of the extent, * possibly including a partial sector at EOF. */ *pnum = MIN(bytes, hole - offset); /* * We are not allowed to return partial sectors, though, so * round up if necessary. */ if (!QEMU_IS_ALIGNED(*pnum, bs->bl.request_alignment)) { int64_t file_length = raw_getlength(bs); if (file_length > 0) { /* Ignore errors, this is just a safeguard */ assert(hole == file_length); } *pnum = ROUND_UP(*pnum, bs->bl.request_alignment); } ret = BDRV_BLOCK_DATA; } else { /* On a hole, compute bytes to the beginning of the next extent. */ assert(hole == offset); *pnum = MIN(bytes, data - offset); ret = BDRV_BLOCK_ZERO; } *map = offset; *file = bs; return ret | BDRV_BLOCK_OFFSET_VALID; } #if defined(__linux__) /* Verify that the file is not in the page cache */ static void check_cache_dropped(BlockDriverState *bs, Error **errp) { const size_t window_size = 128 * 1024 * 1024; BDRVRawState *s = bs->opaque; void *window = NULL; size_t length = 0; unsigned char *vec; size_t page_size; off_t offset; off_t end; /* mincore(2) page status information requires 1 byte per page */ page_size = sysconf(_SC_PAGESIZE); vec = g_malloc(DIV_ROUND_UP(window_size, page_size)); end = raw_getlength(bs); for (offset = 0; offset < end; offset += window_size) { void *new_window; size_t new_length; size_t vec_end; size_t i; int ret; /* Unmap previous window if size has changed */ new_length = MIN(end - offset, window_size); if (new_length != length) { munmap(window, length); window = NULL; length = 0; } new_window = mmap(window, new_length, PROT_NONE, MAP_PRIVATE, s->fd, offset); if (new_window == MAP_FAILED) { error_setg_errno(errp, errno, "mmap failed"); break; } window = new_window; length = new_length; ret = mincore(window, length, vec); if (ret < 0) { error_setg_errno(errp, errno, "mincore failed"); break; } vec_end = DIV_ROUND_UP(length, page_size); for (i = 0; i < vec_end; i++) { if (vec[i] & 0x1) { error_setg(errp, "page cache still in use!"); break; } } } if (window) { munmap(window, length); } g_free(vec); } #endif /* __linux__ */ static void coroutine_fn raw_co_invalidate_cache(BlockDriverState *bs, Error **errp) { BDRVRawState *s = bs->opaque; int ret; ret = fd_open(bs); if (ret < 0) { error_setg_errno(errp, -ret, "The file descriptor is not open"); return; } if (!s->drop_cache) { return; } if (s->open_flags & O_DIRECT) { return; /* No host kernel page cache */ } #if defined(__linux__) /* This sets the scene for the next syscall... */ ret = bdrv_co_flush(bs); if (ret < 0) { error_setg_errno(errp, -ret, "flush failed"); return; } /* Linux does not invalidate pages that are dirty, locked, or mmapped by a * process. These limitations are okay because we just fsynced the file, * we don't use mmap, and the file should not be in use by other processes. */ ret = posix_fadvise(s->fd, 0, 0, POSIX_FADV_DONTNEED); if (ret != 0) { /* the return value is a positive errno */ error_setg_errno(errp, ret, "fadvise failed"); return; } if (s->check_cache_dropped) { check_cache_dropped(bs, errp); } #else /* __linux__ */ /* Do nothing. Live migration to a remote host with cache.direct=off is * unsupported on other host operating systems. Cache consistency issues * may occur but no error is reported here, partly because that's the * historical behavior and partly because it's hard to differentiate valid * configurations that should not cause errors. */ #endif /* !__linux__ */ } static coroutine_fn int raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; acb = (RawPosixAIOData) { .bs = bs, .aio_fildes = s->fd, .aio_type = QEMU_AIO_DISCARD, .aio_offset = offset, .aio_nbytes = bytes, }; if (blkdev) { acb.aio_type |= QEMU_AIO_BLKDEV; } return raw_thread_pool_submit(bs, handle_aiocb_discard, &acb); } static coroutine_fn int raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) { return raw_do_pdiscard(bs, offset, bytes, false); } static int coroutine_fn raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags, bool blkdev) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; ThreadPoolFunc *handler; acb = (RawPosixAIOData) { .bs = bs, .aio_fildes = s->fd, .aio_type = QEMU_AIO_WRITE_ZEROES, .aio_offset = offset, .aio_nbytes = bytes, }; if (blkdev) { acb.aio_type |= QEMU_AIO_BLKDEV; } if (flags & BDRV_REQ_NO_FALLBACK) { acb.aio_type |= QEMU_AIO_NO_FALLBACK; } if (flags & BDRV_REQ_MAY_UNMAP) { acb.aio_type |= QEMU_AIO_DISCARD; handler = handle_aiocb_write_zeroes_unmap; } else { handler = handle_aiocb_write_zeroes; } return raw_thread_pool_submit(bs, handler, &acb); } static int coroutine_fn raw_co_pwrite_zeroes( BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags) { return raw_do_pwrite_zeroes(bs, offset, bytes, flags, false); } static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { BDRVRawState *s = bs->opaque; bdi->unallocated_blocks_are_zero = s->discard_zeroes; return 0; } static QemuOptsList raw_create_opts = { .name = "raw-create-opts", .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head), .desc = { { .name = BLOCK_OPT_SIZE, .type = QEMU_OPT_SIZE, .help = "Virtual disk size" }, { .name = BLOCK_OPT_NOCOW, .type = QEMU_OPT_BOOL, .help = "Turn off copy-on-write (valid only on btrfs)" }, { .name = BLOCK_OPT_PREALLOC, .type = QEMU_OPT_STRING, .help = "Preallocation mode (allowed values: off" #ifdef CONFIG_POSIX_FALLOCATE ", falloc" #endif ", full)" }, { /* end of list */ } } }; static int raw_check_perm(BlockDriverState *bs, uint64_t perm, uint64_t shared, Error **errp) { BDRVRawState *s = bs->opaque; BDRVRawReopenState *rs = NULL; int open_flags; int ret; if (s->perm_change_fd) { /* * In the context of reopen, this function may be called several times * (directly and recursively while change permissions of the parent). * This is even true for children that don't inherit from the original * reopen node, so s->reopen_state is not set. * * Ignore all but the first call. */ return 0; } if (s->reopen_state) { /* We already have a new file descriptor to set permissions for */ assert(s->reopen_state->perm == perm); assert(s->reopen_state->shared_perm == shared); rs = s->reopen_state->opaque; s->perm_change_fd = rs->fd; s->perm_change_flags = rs->open_flags; } else { /* We may need a new fd if auto-read-only switches the mode */ ret = raw_reconfigure_getfd(bs, bs->open_flags, &open_flags, perm, false, errp); if (ret < 0) { return ret; } else if (ret != s->fd) { s->perm_change_fd = ret; s->perm_change_flags = open_flags; } } /* Prepare permissions on old fd to avoid conflicts between old and new, * but keep everything locked that new will need. */ ret = raw_handle_perm_lock(bs, RAW_PL_PREPARE, perm, shared, errp); if (ret < 0) { goto fail; } /* Copy locks to the new fd */ if (s->perm_change_fd) { ret = raw_apply_lock_bytes(NULL, s->perm_change_fd, perm, ~shared, false, errp); if (ret < 0) { raw_handle_perm_lock(bs, RAW_PL_ABORT, 0, 0, NULL); goto fail; } } return 0; fail: if (s->perm_change_fd && !s->reopen_state) { qemu_close(s->perm_change_fd); } s->perm_change_fd = 0; return ret; } static void raw_set_perm(BlockDriverState *bs, uint64_t perm, uint64_t shared) { BDRVRawState *s = bs->opaque; /* For reopen, we have already switched to the new fd (.bdrv_set_perm is * called after .bdrv_reopen_commit) */ if (s->perm_change_fd && s->fd != s->perm_change_fd) { qemu_close(s->fd); s->fd = s->perm_change_fd; s->open_flags = s->perm_change_flags; } s->perm_change_fd = 0; raw_handle_perm_lock(bs, RAW_PL_COMMIT, perm, shared, NULL); s->perm = perm; s->shared_perm = shared; } static void raw_abort_perm_update(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; /* For reopen, .bdrv_reopen_abort is called afterwards and will close * the file descriptor. */ if (s->perm_change_fd && !s->reopen_state) { qemu_close(s->perm_change_fd); } s->perm_change_fd = 0; raw_handle_perm_lock(bs, RAW_PL_ABORT, 0, 0, NULL); } static int coroutine_fn raw_co_copy_range_from( BlockDriverState *bs, BdrvChild *src, uint64_t src_offset, BdrvChild *dst, uint64_t dst_offset, uint64_t bytes, BdrvRequestFlags read_flags, BdrvRequestFlags write_flags) { return bdrv_co_copy_range_to(src, src_offset, dst, dst_offset, bytes, read_flags, write_flags); } static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs, BdrvChild *src, uint64_t src_offset, BdrvChild *dst, uint64_t dst_offset, uint64_t bytes, BdrvRequestFlags read_flags, BdrvRequestFlags write_flags) { RawPosixAIOData acb; BDRVRawState *s = bs->opaque; BDRVRawState *src_s; assert(dst->bs == bs); if (src->bs->drv->bdrv_co_copy_range_to != raw_co_copy_range_to) { return -ENOTSUP; } src_s = src->bs->opaque; if (fd_open(src->bs) < 0 || fd_open(dst->bs) < 0) { return -EIO; } acb = (RawPosixAIOData) { .bs = bs, .aio_type = QEMU_AIO_COPY_RANGE, .aio_fildes = src_s->fd, .aio_offset = src_offset, .aio_nbytes = bytes, .copy_range = { .aio_fd2 = s->fd, .aio_offset2 = dst_offset, }, }; return raw_thread_pool_submit(bs, handle_aiocb_copy_range, &acb); } BlockDriver bdrv_file = { .format_name = "file", .protocol_name = "file", .instance_size = sizeof(BDRVRawState), .bdrv_needs_filename = true, .bdrv_probe = NULL, /* no probe for protocols */ .bdrv_parse_filename = raw_parse_filename, .bdrv_file_open = raw_open, .bdrv_reopen_prepare = raw_reopen_prepare, .bdrv_reopen_commit = raw_reopen_commit, .bdrv_reopen_abort = raw_reopen_abort, .bdrv_close = raw_close, .bdrv_co_create = raw_co_create, .bdrv_co_create_opts = raw_co_create_opts, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_has_zero_init_truncate = bdrv_has_zero_init_1, .bdrv_co_block_status = raw_co_block_status, .bdrv_co_invalidate_cache = raw_co_invalidate_cache, .bdrv_co_pwrite_zeroes = raw_co_pwrite_zeroes, .bdrv_co_preadv = raw_co_preadv, .bdrv_co_pwritev = raw_co_pwritev, .bdrv_co_flush_to_disk = raw_co_flush_to_disk, .bdrv_co_pdiscard = raw_co_pdiscard, .bdrv_co_copy_range_from = raw_co_copy_range_from, .bdrv_co_copy_range_to = raw_co_copy_range_to, .bdrv_refresh_limits = raw_refresh_limits, .bdrv_io_plug = raw_aio_plug, .bdrv_io_unplug = raw_aio_unplug, .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_getlength = raw_getlength, .bdrv_get_info = raw_get_info, .bdrv_get_allocated_file_size = raw_get_allocated_file_size, .bdrv_check_perm = raw_check_perm, .bdrv_set_perm = raw_set_perm, .bdrv_abort_perm_update = raw_abort_perm_update, .create_opts = &raw_create_opts, .mutable_opts = mutable_opts, }; /***********************************************/ /* host device */ #if defined(__APPLE__) && defined(__MACH__) static kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize, int flags); static char *FindEjectableOpticalMedia(io_iterator_t *mediaIterator) { kern_return_t kernResult = KERN_FAILURE; mach_port_t masterPort; CFMutableDictionaryRef classesToMatch; const char *matching_array[] = {kIODVDMediaClass, kIOCDMediaClass}; char *mediaType = NULL; kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort ); if ( KERN_SUCCESS != kernResult ) { printf( "IOMasterPort returned %d\n", kernResult ); } int index; for (index = 0; index < ARRAY_SIZE(matching_array); index++) { classesToMatch = IOServiceMatching(matching_array[index]); if (classesToMatch == NULL) { error_report("IOServiceMatching returned NULL for %s", matching_array[index]); continue; } CFDictionarySetValue(classesToMatch, CFSTR(kIOMediaEjectableKey), kCFBooleanTrue); kernResult = IOServiceGetMatchingServices(masterPort, classesToMatch, mediaIterator); if (kernResult != KERN_SUCCESS) { error_report("Note: IOServiceGetMatchingServices returned %d", kernResult); continue; } /* If a match was found, leave the loop */ if (*mediaIterator != 0) { trace_file_FindEjectableOpticalMedia(matching_array[index]); mediaType = g_strdup(matching_array[index]); break; } } return mediaType; } kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize, int flags) { io_object_t nextMedia; kern_return_t kernResult = KERN_FAILURE; *bsdPath = '\0'; nextMedia = IOIteratorNext( mediaIterator ); if ( nextMedia ) { CFTypeRef bsdPathAsCFString; bsdPathAsCFString = IORegistryEntryCreateCFProperty( nextMedia, CFSTR( kIOBSDNameKey ), kCFAllocatorDefault, 0 ); if ( bsdPathAsCFString ) { size_t devPathLength; strcpy( bsdPath, _PATH_DEV ); if (flags & BDRV_O_NOCACHE) { strcat(bsdPath, "r"); } devPathLength = strlen( bsdPath ); if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) { kernResult = KERN_SUCCESS; } CFRelease( bsdPathAsCFString ); } IOObjectRelease( nextMedia ); } return kernResult; } /* Sets up a real cdrom for use in QEMU */ static bool setup_cdrom(char *bsd_path, Error **errp) { int index, num_of_test_partitions = 2, fd; char test_partition[MAXPATHLEN]; bool partition_found = false; /* look for a working partition */ for (index = 0; index < num_of_test_partitions; index++) { snprintf(test_partition, sizeof(test_partition), "%ss%d", bsd_path, index); fd = qemu_open(test_partition, O_RDONLY | O_BINARY | O_LARGEFILE); if (fd >= 0) { partition_found = true; qemu_close(fd); break; } } /* if a working partition on the device was not found */ if (partition_found == false) { error_setg(errp, "Failed to find a working partition on disc"); } else { trace_file_setup_cdrom(test_partition); pstrcpy(bsd_path, MAXPATHLEN, test_partition); } return partition_found; } /* Prints directions on mounting and unmounting a device */ static void print_unmounting_directions(const char *file_name) { error_report("If device %s is mounted on the desktop, unmount" " it first before using it in QEMU", file_name); error_report("Command to unmount device: diskutil unmountDisk %s", file_name); error_report("Command to mount device: diskutil mountDisk %s", file_name); } #endif /* defined(__APPLE__) && defined(__MACH__) */ static int hdev_probe_device(const char *filename) { struct stat st; /* allow a dedicated CD-ROM driver to match with a higher priority */ if (strstart(filename, "/dev/cdrom", NULL)) return 50; if (stat(filename, &st) >= 0 && (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) { return 100; } return 0; } static int check_hdev_writable(BDRVRawState *s) { #if defined(BLKROGET) /* Linux block devices can be configured "read-only" using blockdev(8). * This is independent of device node permissions and therefore open(2) * with O_RDWR succeeds. Actual writes fail with EPERM. * * bdrv_open() is supposed to fail if the disk is read-only. Explicitly * check for read-only block devices so that Linux block devices behave * properly. */ struct stat st; int readonly = 0; if (fstat(s->fd, &st)) { return -errno; } if (!S_ISBLK(st.st_mode)) { return 0; } if (ioctl(s->fd, BLKROGET, &readonly) < 0) { return -errno; } if (readonly) { return -EACCES; } #endif /* defined(BLKROGET) */ return 0; } static void hdev_parse_filename(const char *filename, QDict *options, Error **errp) { bdrv_parse_filename_strip_prefix(filename, "host_device:", options); } static bool hdev_is_sg(BlockDriverState *bs) { #if defined(__linux__) BDRVRawState *s = bs->opaque; struct stat st; struct sg_scsi_id scsiid; int sg_version; int ret; if (stat(bs->filename, &st) < 0 || !S_ISCHR(st.st_mode)) { return false; } ret = ioctl(s->fd, SG_GET_VERSION_NUM, &sg_version); if (ret < 0) { return false; } ret = ioctl(s->fd, SG_GET_SCSI_ID, &scsiid); if (ret >= 0) { trace_file_hdev_is_sg(scsiid.scsi_type, sg_version); return true; } #endif return false; } static int hdev_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVRawState *s = bs->opaque; Error *local_err = NULL; int ret; #if defined(__APPLE__) && defined(__MACH__) /* * Caution: while qdict_get_str() is fine, getting non-string types * would require more care. When @options come from -blockdev or * blockdev_add, its members are typed according to the QAPI * schema, but when they come from -drive, they're all QString. */ const char *filename = qdict_get_str(options, "filename"); char bsd_path[MAXPATHLEN] = ""; bool error_occurred = false; /* If using a real cdrom */ if (strcmp(filename, "/dev/cdrom") == 0) { char *mediaType = NULL; kern_return_t ret_val; io_iterator_t mediaIterator = 0; mediaType = FindEjectableOpticalMedia(&mediaIterator); if (mediaType == NULL) { error_setg(errp, "Please make sure your CD/DVD is in the optical" " drive"); error_occurred = true; goto hdev_open_Mac_error; } ret_val = GetBSDPath(mediaIterator, bsd_path, sizeof(bsd_path), flags); if (ret_val != KERN_SUCCESS) { error_setg(errp, "Could not get BSD path for optical drive"); error_occurred = true; goto hdev_open_Mac_error; } /* If a real optical drive was not found */ if (bsd_path[0] == '\0') { error_setg(errp, "Failed to obtain bsd path for optical drive"); error_occurred = true; goto hdev_open_Mac_error; } /* If using a cdrom disc and finding a partition on the disc failed */ if (strncmp(mediaType, kIOCDMediaClass, 9) == 0 && setup_cdrom(bsd_path, errp) == false) { print_unmounting_directions(bsd_path); error_occurred = true; goto hdev_open_Mac_error; } qdict_put_str(options, "filename", bsd_path); hdev_open_Mac_error: g_free(mediaType); if (mediaIterator) { IOObjectRelease(mediaIterator); } if (error_occurred) { return -ENOENT; } } #endif /* defined(__APPLE__) && defined(__MACH__) */ s->type = FTYPE_FILE; ret = raw_open_common(bs, options, flags, 0, true, &local_err); if (ret < 0) { error_propagate(errp, local_err); #if defined(__APPLE__) && defined(__MACH__) if (*bsd_path) { filename = bsd_path; } /* if a physical device experienced an error while being opened */ if (strncmp(filename, "/dev/", 5) == 0) { print_unmounting_directions(filename); } #endif /* defined(__APPLE__) && defined(__MACH__) */ return ret; } /* Since this does ioctl the device must be already opened */ bs->sg = hdev_is_sg(bs); if (flags & BDRV_O_RDWR) { ret = check_hdev_writable(s); if (ret < 0) { raw_close(bs); error_setg_errno(errp, -ret, "The device is not writable"); return ret; } } return ret; } #if defined(__linux__) static int coroutine_fn hdev_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) { BDRVRawState *s = bs->opaque; RawPosixAIOData acb; int ret; ret = fd_open(bs); if (ret < 0) { return ret; } if (req == SG_IO && s->pr_mgr) { struct sg_io_hdr *io_hdr = buf; if (io_hdr->cmdp[0] == PERSISTENT_RESERVE_OUT || io_hdr->cmdp[0] == PERSISTENT_RESERVE_IN) { return pr_manager_execute(s->pr_mgr, bdrv_get_aio_context(bs), s->fd, io_hdr); } } acb = (RawPosixAIOData) { .bs = bs, .aio_type = QEMU_AIO_IOCTL, .aio_fildes = s->fd, .aio_offset = 0, .ioctl = { .buf = buf, .cmd = req, }, }; return raw_thread_pool_submit(bs, handle_aiocb_ioctl, &acb); } #endif /* linux */ static int fd_open(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; /* this is just to ensure s->fd is sane (its called by io ops) */ if (s->fd >= 0) return 0; return -EIO; } static coroutine_fn int hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) { int ret; ret = fd_open(bs); if (ret < 0) { return ret; } return raw_do_pdiscard(bs, offset, bytes, true); } static coroutine_fn int hdev_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags) { int rc; rc = fd_open(bs); if (rc < 0) { return rc; } return raw_do_pwrite_zeroes(bs, offset, bytes, flags, true); } static int coroutine_fn hdev_co_create_opts(const char *filename, QemuOpts *opts, Error **errp) { int fd; int ret = 0; struct stat stat_buf; int64_t total_size = 0; bool has_prefix; /* This function is used by both protocol block drivers and therefore either * of these prefixes may be given. * The return value has to be stored somewhere, otherwise this is an error * due to -Werror=unused-value. */ has_prefix = strstart(filename, "host_device:", &filename) || strstart(filename, "host_cdrom:" , &filename); (void)has_prefix; ret = raw_normalize_devicepath(&filename, errp); if (ret < 0) { return ret; } /* Read out options */ total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), BDRV_SECTOR_SIZE); fd = qemu_open(filename, O_WRONLY | O_BINARY); if (fd < 0) { ret = -errno; error_setg_errno(errp, -ret, "Could not open device"); return ret; } if (fstat(fd, &stat_buf) < 0) { ret = -errno; error_setg_errno(errp, -ret, "Could not stat device"); } else if (!S_ISBLK(stat_buf.st_mode) && !S_ISCHR(stat_buf.st_mode)) { error_setg(errp, "The given file is neither a block nor a character device"); ret = -ENODEV; } else if (lseek(fd, 0, SEEK_END) < total_size) { error_setg(errp, "Device is too small"); ret = -ENOSPC; } if (!ret && total_size) { uint8_t buf[BDRV_SECTOR_SIZE] = { 0 }; int64_t zero_size = MIN(BDRV_SECTOR_SIZE, total_size); if (lseek(fd, 0, SEEK_SET) == -1) { ret = -errno; } else { ret = qemu_write_full(fd, buf, zero_size); ret = ret == zero_size ? 0 : -errno; } } qemu_close(fd); return ret; } static BlockDriver bdrv_host_device = { .format_name = "host_device", .protocol_name = "host_device", .instance_size = sizeof(BDRVRawState), .bdrv_needs_filename = true, .bdrv_probe_device = hdev_probe_device, .bdrv_parse_filename = hdev_parse_filename, .bdrv_file_open = hdev_open, .bdrv_close = raw_close, .bdrv_reopen_prepare = raw_reopen_prepare, .bdrv_reopen_commit = raw_reopen_commit, .bdrv_reopen_abort = raw_reopen_abort, .bdrv_co_create_opts = hdev_co_create_opts, .create_opts = &raw_create_opts, .mutable_opts = mutable_opts, .bdrv_co_invalidate_cache = raw_co_invalidate_cache, .bdrv_co_pwrite_zeroes = hdev_co_pwrite_zeroes, .bdrv_co_preadv = raw_co_preadv, .bdrv_co_pwritev = raw_co_pwritev, .bdrv_co_flush_to_disk = raw_co_flush_to_disk, .bdrv_co_pdiscard = hdev_co_pdiscard, .bdrv_co_copy_range_from = raw_co_copy_range_from, .bdrv_co_copy_range_to = raw_co_copy_range_to, .bdrv_refresh_limits = raw_refresh_limits, .bdrv_io_plug = raw_aio_plug, .bdrv_io_unplug = raw_aio_unplug, .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_getlength = raw_getlength, .bdrv_get_info = raw_get_info, .bdrv_get_allocated_file_size = raw_get_allocated_file_size, .bdrv_check_perm = raw_check_perm, .bdrv_set_perm = raw_set_perm, .bdrv_abort_perm_update = raw_abort_perm_update, .bdrv_probe_blocksizes = hdev_probe_blocksizes, .bdrv_probe_geometry = hdev_probe_geometry, /* generic scsi device */ #ifdef __linux__ .bdrv_co_ioctl = hdev_co_ioctl, #endif }; #if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) static void cdrom_parse_filename(const char *filename, QDict *options, Error **errp) { bdrv_parse_filename_strip_prefix(filename, "host_cdrom:", options); } #endif #ifdef __linux__ static int cdrom_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVRawState *s = bs->opaque; s->type = FTYPE_CD; /* open will not fail even if no CD is inserted, so add O_NONBLOCK */ return raw_open_common(bs, options, flags, O_NONBLOCK, true, errp); } static int cdrom_probe_device(const char *filename) { int fd, ret; int prio = 0; struct stat st; fd = qemu_open(filename, O_RDONLY | O_NONBLOCK); if (fd < 0) { goto out; } ret = fstat(fd, &st); if (ret == -1 || !S_ISBLK(st.st_mode)) { goto outc; } /* Attempt to detect via a CDROM specific ioctl */ ret = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT); if (ret >= 0) prio = 100; outc: qemu_close(fd); out: return prio; } static bool cdrom_is_inserted(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; int ret; ret = ioctl(s->fd, CDROM_DRIVE_STATUS, CDSL_CURRENT); return ret == CDS_DISC_OK; } static void cdrom_eject(BlockDriverState *bs, bool eject_flag) { BDRVRawState *s = bs->opaque; if (eject_flag) { if (ioctl(s->fd, CDROMEJECT, NULL) < 0) perror("CDROMEJECT"); } else { if (ioctl(s->fd, CDROMCLOSETRAY, NULL) < 0) perror("CDROMEJECT"); } } static void cdrom_lock_medium(BlockDriverState *bs, bool locked) { BDRVRawState *s = bs->opaque; if (ioctl(s->fd, CDROM_LOCKDOOR, locked) < 0) { /* * Note: an error can happen if the distribution automatically * mounts the CD-ROM */ /* perror("CDROM_LOCKDOOR"); */ } } static BlockDriver bdrv_host_cdrom = { .format_name = "host_cdrom", .protocol_name = "host_cdrom", .instance_size = sizeof(BDRVRawState), .bdrv_needs_filename = true, .bdrv_probe_device = cdrom_probe_device, .bdrv_parse_filename = cdrom_parse_filename, .bdrv_file_open = cdrom_open, .bdrv_close = raw_close, .bdrv_reopen_prepare = raw_reopen_prepare, .bdrv_reopen_commit = raw_reopen_commit, .bdrv_reopen_abort = raw_reopen_abort, .bdrv_co_create_opts = hdev_co_create_opts, .create_opts = &raw_create_opts, .mutable_opts = mutable_opts, .bdrv_co_invalidate_cache = raw_co_invalidate_cache, .bdrv_co_preadv = raw_co_preadv, .bdrv_co_pwritev = raw_co_pwritev, .bdrv_co_flush_to_disk = raw_co_flush_to_disk, .bdrv_refresh_limits = raw_refresh_limits, .bdrv_io_plug = raw_aio_plug, .bdrv_io_unplug = raw_aio_unplug, .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_getlength = raw_getlength, .has_variable_length = true, .bdrv_get_allocated_file_size = raw_get_allocated_file_size, /* removable device support */ .bdrv_is_inserted = cdrom_is_inserted, .bdrv_eject = cdrom_eject, .bdrv_lock_medium = cdrom_lock_medium, /* generic scsi device */ .bdrv_co_ioctl = hdev_co_ioctl, }; #endif /* __linux__ */ #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) static int cdrom_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVRawState *s = bs->opaque; Error *local_err = NULL; int ret; s->type = FTYPE_CD; ret = raw_open_common(bs, options, flags, 0, true, &local_err); if (ret) { error_propagate(errp, local_err); return ret; } /* make sure the door isn't locked at this time */ ioctl(s->fd, CDIOCALLOW); return 0; } static int cdrom_probe_device(const char *filename) { if (strstart(filename, "/dev/cd", NULL) || strstart(filename, "/dev/acd", NULL)) return 100; return 0; } static int cdrom_reopen(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; int fd; /* * Force reread of possibly changed/newly loaded disc, * FreeBSD seems to not notice sometimes... */ if (s->fd >= 0) qemu_close(s->fd); fd = qemu_open(bs->filename, s->open_flags, 0644); if (fd < 0) { s->fd = -1; return -EIO; } s->fd = fd; /* make sure the door isn't locked at this time */ ioctl(s->fd, CDIOCALLOW); return 0; } static bool cdrom_is_inserted(BlockDriverState *bs) { return raw_getlength(bs) > 0; } static void cdrom_eject(BlockDriverState *bs, bool eject_flag) { BDRVRawState *s = bs->opaque; if (s->fd < 0) return; (void) ioctl(s->fd, CDIOCALLOW); if (eject_flag) { if (ioctl(s->fd, CDIOCEJECT) < 0) perror("CDIOCEJECT"); } else { if (ioctl(s->fd, CDIOCCLOSE) < 0) perror("CDIOCCLOSE"); } cdrom_reopen(bs); } static void cdrom_lock_medium(BlockDriverState *bs, bool locked) { BDRVRawState *s = bs->opaque; if (s->fd < 0) return; if (ioctl(s->fd, (locked ? CDIOCPREVENT : CDIOCALLOW)) < 0) { /* * Note: an error can happen if the distribution automatically * mounts the CD-ROM */ /* perror("CDROM_LOCKDOOR"); */ } } static BlockDriver bdrv_host_cdrom = { .format_name = "host_cdrom", .protocol_name = "host_cdrom", .instance_size = sizeof(BDRVRawState), .bdrv_needs_filename = true, .bdrv_probe_device = cdrom_probe_device, .bdrv_parse_filename = cdrom_parse_filename, .bdrv_file_open = cdrom_open, .bdrv_close = raw_close, .bdrv_reopen_prepare = raw_reopen_prepare, .bdrv_reopen_commit = raw_reopen_commit, .bdrv_reopen_abort = raw_reopen_abort, .bdrv_co_create_opts = hdev_co_create_opts, .create_opts = &raw_create_opts, .mutable_opts = mutable_opts, .bdrv_co_preadv = raw_co_preadv, .bdrv_co_pwritev = raw_co_pwritev, .bdrv_co_flush_to_disk = raw_co_flush_to_disk, .bdrv_refresh_limits = raw_refresh_limits, .bdrv_io_plug = raw_aio_plug, .bdrv_io_unplug = raw_aio_unplug, .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_getlength = raw_getlength, .has_variable_length = true, .bdrv_get_allocated_file_size = raw_get_allocated_file_size, /* removable device support */ .bdrv_is_inserted = cdrom_is_inserted, .bdrv_eject = cdrom_eject, .bdrv_lock_medium = cdrom_lock_medium, }; #endif /* __FreeBSD__ */ static void bdrv_file_init(void) { /* * Register all the drivers. Note that order is important, the driver * registered last will get probed first. */ bdrv_register(&bdrv_file); bdrv_register(&bdrv_host_device); #ifdef __linux__ bdrv_register(&bdrv_host_cdrom); #endif #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) bdrv_register(&bdrv_host_cdrom); #endif } block_init(bdrv_file_init);