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qemu/block/file-posix.c
Kevin Wolf ffa244c84a file-posix: Mitigate file fragmentation with extent size hints 
Especially when O_DIRECT is used with image files so that the page cache
indirection can't cause a merge of allocating requests, the file will
fragment on the file system layer, with a potentially very small
fragment size (this depends on the requests the guest sent).

On Linux, fragmentation can be reduced by setting an extent size hint
when creating the file (at least on XFS, it can't be set any more after
the first extent has been allocated), basically giving raw files a
"cluster size" for allocation.

This adds a create option to set the extent size hint, and changes the
default from not setting a hint to setting it to 1 MB. The main reason
why qcow2 defaults to smaller cluster sizes is that COW becomes more
expensive, which is not an issue with raw files, so we can choose a
larger size. The tradeoff here is only potentially wasted disk space.

For qcow2 (or other image formats) over file-posix, the advantage should
even be greater because they grow sequentially without leaving holes, so
there won't be wasted space. Setting even larger extent size hints for
such images may make sense. This can be done with the new option, but
let's keep the default conservative for now.

The effect is very visible with a test that intentionally creates a
badly fragmented file with qemu-img bench (the time difference while
creating the file is already remarkable) and then looks at the number of
extents and the time a simple "qemu-img map" takes.

Without an extent size hint:

    $ ./qemu-img create -f raw -o extent_size_hint=0 ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=0
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 25.848 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 19.616 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 2000000 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m1,279s
    user    0m0,043s
    sys     0m1,226s

With the new default extent size hint of 1 MB:

    $ ./qemu-img create -f raw -o extent_size_hint=1M ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=1048576
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 11.833 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 10.155 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 178 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m0,061s
    user    0m0,040s
    sys     0m0,014s

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200707142329.48303-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00

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/*
* 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 "qemu/units.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 <paths.h>
#include <sys/param.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/IOBSD.h>
#include <IOKit/storage/IOMediaBSDClient.h>
#include <IOKit/storage/IOMedia.h>
#include <IOKit/storage/IOCDMedia.h>
//#include <IOKit/storage/IOCDTypes.h>
#include <IOKit/storage/IODVDMedia.h>
#include <CoreFoundation/CoreFoundation.h>
#endif
#ifdef __sun__
#define _POSIX_PTHREAD_SEMANTICS 1
#include <sys/dkio.h>
#endif
#ifdef __linux__
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/syscall.h>
#include <linux/cdrom.h>
#include <linux/fd.h>
#include <linux/fs.h>
#include <linux/hdreg.h>
#include <scsi/sg.h>
#ifdef __s390__
#include <asm/dasd.h>
#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 <linux/falloc.h>
#endif
#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
#include <sys/disk.h>
#include <sys/cdio.h>
#endif
#ifdef __OpenBSD__
#include <sys/ioctl.h>
#include <sys/disklabel.h>
#include <sys/dkio.h>
#endif
#ifdef __NetBSD__
#include <sys/ioctl.h>
#include <sys/disklabel.h>
#include <sys/dkio.h>
#include <sys/disk.h>
#endif
#ifdef __DragonFly__
#include <sys/ioctl.h>
#include <sys/diskslice.h>
#endif
#ifdef CONFIG_XFS
#include <xfs/xfs.h>
#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 use_linux_io_uring:1;
bool page_cache_inconsistent:1;
bool has_fallocate;
bool needs_alignment;
bool drop_cache;
bool check_cache_dropped;
struct {
uint64_t discard_nb_ok;
uint64_t discard_nb_failed;
uint64_t discard_bytes_ok;
} stats;
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], &sector_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, qemu_real_host_page_size);
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_alignment. */
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, io_uring)",
},
{
.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);
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
ret = -EINVAL;
goto fail;
}
filename = qemu_opt_get(opts, "filename");
ret = raw_normalize_devicepath(&filename, errp);
if (ret != 0) {
goto fail;
}
if (bdrv_flags & BDRV_O_NATIVE_AIO) {
aio_default = BLOCKDEV_AIO_OPTIONS_NATIVE;
#ifdef CONFIG_LINUX_IO_URING
} else if (bdrv_flags & BDRV_O_IO_URING) {
aio_default = BLOCKDEV_AIO_OPTIONS_IO_URING;
#endif
} else {
aio_default = 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);
#ifdef CONFIG_LINUX_IO_URING
s->use_linux_io_uring = (aio == BLOCKDEV_AIO_OPTIONS_IO_URING);
#endif
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) */
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
if (!aio_setup_linux_io_uring(bdrv_get_aio_context(bs), errp)) {
error_prepend(errp, "Unable to use io_uring: ");
goto fail;
}
}
#else
if (s->use_linux_io_uring) {
error_setg(errp, "aio=io_uring was specified, but is not supported "
"in this build.");
ret = -EINVAL;
goto fail;
}
#endif /* !defined(CONFIG_LINUX_IO_URING) */
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;
if (S_ISREG(st.st_mode)) {
/* When extending regular files, we get zeros from the OS */
bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
}
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);
}
/* 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);
if (!qemu_opts_absorb_qdict(opts, state->options, errp)) {
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 * qemu_real_host_page_size);
}
}
raw_probe_alignment(bs, s->fd, errp);
bs->bl.min_mem_alignment = s->buf_align;
bs->bl.opt_mem_alignment = MAX(s->buf_align, qemu_real_host_page_size);
}
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;
}
}
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);
if (ret == -ENOTSUP) {
s->has_write_zeroes = false;
}
}
#endif
return ret;
}
static int handle_aiocb_write_zeroes(void *opaque)
{
RawPosixAIOData *aiocb = opaque;
#ifdef CONFIG_FALLOCATE
BDRVRawState *s = aiocb->bs->opaque;
int64_t len;
#endif
if (aiocb->aio_type & QEMU_AIO_BLKDEV) {
return handle_aiocb_write_zeroes_block(aiocb);
}
#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 == -EINVAL) {
/*
* Allow falling back to pwrite for file systems that
* do not support fallocate() for an unaligned byte range.
*/
return -ENOTSUP;
}
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;
/* First try to write zeros and unmap at the same time */
#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
int 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
/* If we couldn't manage to unmap while guaranteed that the area reads as
* all-zero afterwards, just write zeroes without unmapping */
return handle_aiocb_write_zeroes(aiocb);
}
#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_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;
}
/*
* Help alignment probing by allocating the first block.
*
* When reading with direct I/O from unallocated area on Gluster backed by XFS,
* reading succeeds regardless of request length. In this case we fallback to
* safe alignment which is not optimal. Allocating the first block avoids this
* fallback.
*
* fd may be opened with O_DIRECT, but we don't know the buffer alignment or
* request alignment, so we use safe values.
*
* Returns: 0 on success, -errno on failure. Since this is an optimization,
* caller may ignore failures.
*/
static int allocate_first_block(int fd, size_t max_size)
{
size_t write_size = (max_size < MAX_BLOCKSIZE)
? BDRV_SECTOR_SIZE
: MAX_BLOCKSIZE;
size_t max_align = MAX(MAX_BLOCKSIZE, qemu_real_host_page_size);
void *buf;
ssize_t n;
int ret;
buf = qemu_memalign(max_align, write_size);
memset(buf, 0, write_size);
do {
n = pwrite(fd, buf, write_size, 0);
} while (n == -1 && errno == EINTR);
ret = (n == -1) ? -errno : 0;
qemu_vfree(buf);
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 if (current_length == 0) {
/*
* posix_fallocate() uses fallocate() if the filesystem
* supports it, or fallback to manually writing zeroes. If
* fallocate() was used, unaligned reads from the fallocated
* area in raw_probe_alignment() will succeed, hence we need to
* allocate the first block.
*
* Optimize future alignment probing; ignore failures.
*/
allocate_first_block(fd, offset);
}
} 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");
} else if (current_length == 0 && offset > current_length) {
/* Optimize future alignment probing; ignore failures. */
allocate_first_block(fd, offset);
}
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;
/*
* When using O_DIRECT, the request must be aligned to be able to use
* either libaio or io_uring interface. If not fail back to regular thread
* pool read/write code which emulates this for us if we
* set QEMU_AIO_MISALIGNED.
*/
if (s->needs_alignment && !bdrv_qiov_is_aligned(bs, qiov)) {
type |= QEMU_AIO_MISALIGNED;
#ifdef CONFIG_LINUX_IO_URING
} else if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
assert(qiov->size == bytes);
return luring_co_submit(bs, aio, s->fd, offset, qiov, type);
#endif
#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)
{
BDRVRawState __attribute__((unused)) *s = bs->opaque;
#ifdef CONFIG_LINUX_AIO
if (s->use_linux_aio) {
LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
laio_io_plug(bs, aio);
}
#endif
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
luring_io_plug(bs, aio);
}
#endif
}
static void raw_aio_unplug(BlockDriverState *bs)
{
BDRVRawState __attribute__((unused)) *s = bs->opaque;
#ifdef CONFIG_LINUX_AIO
if (s->use_linux_aio) {
LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
laio_io_unplug(bs, aio);
}
#endif
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
luring_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,
};
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
return luring_co_submit(bs, aio, s->fd, 0, NULL, QEMU_AIO_FLUSH);
}
#endif
return raw_thread_pool_submit(bs, handle_aiocb_flush, &acb);
}
static void raw_aio_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
BDRVRawState __attribute__((unused)) *s = bs->opaque;
#ifdef CONFIG_LINUX_AIO
if (s->use_linux_aio) {
Error *local_err = NULL;
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
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
Error *local_err;
if (!aio_setup_linux_io_uring(new_context, &local_err)) {
error_reportf_err(local_err, "Unable to use linux io_uring, "
"falling back to thread pool: ");
s->use_linux_io_uring = 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,
bool exact, PreallocMode prealloc,
BdrvRequestFlags flags, 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)) {
/* Always resizes to the exact @offset */
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)) {
int64_t cur_length = raw_getlength(bs);
if (offset != cur_length && exact) {
error_setg(errp, "Cannot resize device files");
return -ENOTSUP;
} else if (offset > cur_length) {
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, &sectors) == 0
&& ioctl(fd, DKIOCGETBLOCKSIZE, &sector_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;
}
if (!file_opts->has_extent_size_hint) {
file_opts->extent_size_hint = 1 * MiB;
}
if (file_opts->extent_size_hint > UINT32_MAX) {
result = -EINVAL;
error_setg(errp, "Extent size hint is too large");
goto out;
}
/* 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
}
#ifdef FS_IOC_FSSETXATTR
/*
* Try to set the extent size hint. Failure is not fatal, and a warning is
* only printed if the option was explicitly specified.
*/
{
struct fsxattr attr;
result = ioctl(fd, FS_IOC_FSGETXATTR, &attr);
if (result == 0) {
attr.fsx_xflags |= FS_XFLAG_EXTSIZE;
attr.fsx_extsize = file_opts->extent_size_hint;
result = ioctl(fd, FS_IOC_FSSETXATTR, &attr);
}
if (result < 0 && file_opts->has_extent_size_hint &&
file_opts->extent_size_hint)
{
warn_report("Failed to set extent size hint: %s",
strerror(errno));
}
}
#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(BlockDriver *drv,
const char *filename,
QemuOpts *opts,
Error **errp)
{
BlockdevCreateOptions options;
int64_t total_size = 0;
int64_t extent_size_hint = 0;
bool has_extent_size_hint = false;
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);
if (qemu_opt_get(opts, BLOCK_OPT_EXTENT_SIZE_HINT)) {
has_extent_size_hint = true;
extent_size_hint =
qemu_opt_get_size_del(opts, BLOCK_OPT_EXTENT_SIZE_HINT, -1);
}
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,
.has_extent_size_hint = has_extent_size_hint,
.extent_size_hint = extent_size_hint,
},
};
return raw_co_create(&options, errp);
}
static int coroutine_fn raw_co_delete_file(BlockDriverState *bs,
Error **errp)
{
struct stat st;
int ret;
if (!(stat(bs->filename, &st) == 0) || !S_ISREG(st.st_mode)) {
error_setg_errno(errp, ENOENT, "%s is not a regular file",
bs->filename);
return -ENOENT;
}
ret = unlink(bs->filename);
if (ret < 0) {
ret = -errno;
error_setg_errno(errp, -ret, "Error when deleting file %s",
bs->filename);
}
return ret;
}
/*
* 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) {
break;
}
}
if (i < vec_end) {
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 void raw_account_discard(BDRVRawState *s, uint64_t nbytes, int ret)
{
if (ret) {
s->stats.discard_nb_failed++;
} else {
s->stats.discard_nb_ok++;
s->stats.discard_bytes_ok += nbytes;
}
}
static coroutine_fn int
raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
{
BDRVRawState *s = bs->opaque;
RawPosixAIOData acb;
int ret;
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;
}
ret = raw_thread_pool_submit(bs, handle_aiocb_discard, &acb);
raw_account_discard(s, bytes, ret);
return ret;
}
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;
#ifdef CONFIG_FALLOCATE
if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
BdrvTrackedRequest *req;
uint64_t end;
/*
* This is a workaround for a bug in the Linux XFS driver,
* where writes submitted through the AIO interface will be
* discarded if they happen beyond a concurrently running
* fallocate() that increases the file length (i.e., both the
* write and the fallocate() happen beyond the EOF).
*
* To work around it, we extend the tracked request for this
* zero write until INT64_MAX (effectively infinity), and mark
* it as serializing.
*
* We have to enable this workaround for all filesystems and
* AIO modes (not just XFS with aio=native), because for
* remote filesystems we do not know the host configuration.
*/
req = bdrv_co_get_self_request(bs);
assert(req);
assert(req->type == BDRV_TRACKED_WRITE);
assert(req->offset <= offset);
assert(req->offset + req->bytes >= offset + bytes);
end = INT64_MAX & -(uint64_t)bs->bl.request_alignment;
req->bytes = end - req->offset;
req->overlap_bytes = req->bytes;
bdrv_mark_request_serialising(req, bs->bl.request_alignment);
}
#endif
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)
{
return 0;
}
static BlockStatsSpecificFile get_blockstats_specific_file(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
return (BlockStatsSpecificFile) {
.discard_nb_ok = s->stats.discard_nb_ok,
.discard_nb_failed = s->stats.discard_nb_failed,
.discard_bytes_ok = s->stats.discard_bytes_ok,
};
}
static BlockStatsSpecific *raw_get_specific_stats(BlockDriverState *bs)
{
BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
stats->driver = BLOCKDEV_DRIVER_FILE;
stats->u.file = get_blockstats_specific_file(bs);
return stats;
}
static BlockStatsSpecific *hdev_get_specific_stats(BlockDriverState *bs)
{
BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
stats->driver = BLOCKDEV_DRIVER_HOST_DEVICE;
stats->u.host_device = get_blockstats_specific_file(bs);
return stats;
}
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)"
},
{
.name = BLOCK_OPT_EXTENT_SIZE_HINT,
.type = QEMU_OPT_SIZE,
.help = "Extent size hint for the image file, 0 to disable"
},
{ /* 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_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_delete_file = raw_co_delete_file,
.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_get_specific_stats = raw_get_specific_stats,
.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;
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, errp);
if (ret < 0) {
#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)
{
BDRVRawState *s = bs->opaque;
int ret;
ret = fd_open(bs);
if (ret < 0) {
raw_account_discard(s, bytes, ret);
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 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 = bdrv_co_create_opts_simple,
.create_opts = &bdrv_create_opts_simple,
.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_get_specific_stats = hdev_get_specific_stats,
.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 = bdrv_co_create_opts_simple,
.create_opts = &bdrv_create_opts_simple,
.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;
int ret;
s->type = FTYPE_CD;
ret = raw_open_common(bs, options, flags, 0, true, errp);
if (ret) {
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 = bdrv_co_create_opts_simple,
.create_opts = &bdrv_create_opts_simple,
.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);
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