| Message ID | 95fe2a778152f50d942dcb17872927247195d0b1.1294150511.git.quintela@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Jan 4, 2011 at 2:33 PM, Juan Quintela <quintela@redhat.com> wrote: > Linux allows to invalidate block devices. This is needed for the incoming > migration part. > > Signed-off-by: Juan Quintela <quintela@redhat.com> > --- > block.h | 2 ++ > block/raw-posix.c | 24 ++++++++++++++++++++++++ > blockdev.c | 9 +++++---- > 3 files changed, 31 insertions(+), 4 deletions(-) > > diff --git a/block.h b/block.h > index f923add..5ac96a5 100644 > --- a/block.h > +++ b/block.h > @@ -34,6 +34,8 @@ typedef struct QEMUSnapshotInfo { > #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */ > #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */ > #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */ > +#define BDRV_O_INVALIDATE 0x0400 /* invalidate buffer cache for this device. > + re-read things from server */ > > #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH) > > diff --git a/block/raw-posix.c b/block/raw-posix.c > index 6b72470..9439cf1 100644 > --- a/block/raw-posix.c > +++ b/block/raw-posix.c > @@ -51,6 +51,7 @@ > #include <sys/param.h> > #include <linux/cdrom.h> > #include <linux/fd.h> > +#include <linux/fs.h> > #endif > #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) > #include <signal.h> > @@ -168,6 +169,29 @@ static int raw_open_common(BlockDriverState *bs, const char *filename, > s->fd = fd; > s->aligned_buf = NULL; > > +#ifdef __linux__ > + if ((bdrv_flags & BDRV_O_INVALIDATE)) { > + struct stat buf; > + int res; > + > + res = fstat(fd, &buf); > + > + if (res < 0) { > + return -errno; > + } > + > + if (S_ISBLK(buf.st_mode)) { > + printf("we are in a block device: %s\n", filename); Leftover debugging?
Blue Swirl <blauwirbel@gmail.com> wrote: > On Tue, Jan 4, 2011 at 2:33 PM, Juan Quintela <quintela@redhat.com> wrote: >> Linux allows to invalidate block devices. This is needed for the incoming >> migration part. >> >> Signed-off-by: Juan Quintela <quintela@redhat.com> >> --- >> block.h | 2 ++ >> block/raw-posix.c | 24 ++++++++++++++++++++++++ >> blockdev.c | 9 +++++---- >> 3 files changed, 31 insertions(+), 4 deletions(-) >> >> diff --git a/block.h b/block.h >> index f923add..5ac96a5 100644 >> --- a/block.h >> +++ b/block.h >> @@ -34,6 +34,8 @@ typedef struct QEMUSnapshotInfo { >> #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */ >> #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */ >> #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */ >> +#define BDRV_O_INVALIDATE 0x0400 /* invalidate buffer cache for this device. >> + re-read things from server */ >> >> #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH) >> >> diff --git a/block/raw-posix.c b/block/raw-posix.c >> index 6b72470..9439cf1 100644 >> --- a/block/raw-posix.c >> +++ b/block/raw-posix.c >> @@ -51,6 +51,7 @@ >> #include <sys/param.h> >> #include <linux/cdrom.h> >> #include <linux/fd.h> >> +#include <linux/fs.h> >> #endif >> #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) >> #include <signal.h> >> @@ -168,6 +169,29 @@ static int raw_open_common(BlockDriverState *bs, const char *filename, >> s->fd = fd; >> s->aligned_buf = NULL; >> >> +#ifdef __linux__ >> + if ((bdrv_flags & BDRV_O_INVALIDATE)) { >> + struct stat buf; >> + int res; >> + >> + res = fstat(fd, &buf); >> + >> + if (res < 0) { >> + return -errno; >> + } >> + >> + if (S_ISBLK(buf.st_mode)) { >> + printf("we are in a block device: %s\n", filename); > > Leftover debugging? ouch, yes. thanks for the spotting. Later, Juan.
On Tue, Jan 04, 2011 at 03:33:30PM +0100, Juan Quintela wrote: > Linux allows to invalidate block devices. This is needed for the incoming > migration part. It's not. The only thing that makes migration on block devices safe is using O_DIRECT, aka cache=none.
diff --git a/block.h b/block.h index f923add..5ac96a5 100644 --- a/block.h +++ b/block.h @@ -34,6 +34,8 @@ typedef struct QEMUSnapshotInfo { #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */ #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */ #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */ +#define BDRV_O_INVALIDATE 0x0400 /* invalidate buffer cache for this device. + re-read things from server */ #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH) diff --git a/block/raw-posix.c b/block/raw-posix.c index 6b72470..9439cf1 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -51,6 +51,7 @@ #include <sys/param.h> #include <linux/cdrom.h> #include <linux/fd.h> +#include <linux/fs.h> #endif #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) #include <signal.h> @@ -168,6 +169,29 @@ static int raw_open_common(BlockDriverState *bs, const char *filename, s->fd = fd; s->aligned_buf = NULL; +#ifdef __linux__ + if ((bdrv_flags & BDRV_O_INVALIDATE)) { + struct stat buf; + int res; + + res = fstat(fd, &buf); + + if (res < 0) { + return -errno; + } + + if (S_ISBLK(buf.st_mode)) { + printf("we are in a block device: %s\n", filename); + res = ioctl(fd, BLKFLSBUF, 0); + if (res < 0) { + fprintf(stderr, "qemu: buffer invalidation of %s" + " failed with error %d\n", filename, errno); + return -errno; + } + } + } +#endif /* __linux__ */ + if ((bdrv_flags & BDRV_O_NOCACHE)) { /* * Allocate a buffer for read/modify/write cycles. Chose the size diff --git a/blockdev.c b/blockdev.c index 3f3df7a..94920b8 100644 --- a/blockdev.c +++ b/blockdev.c @@ -137,9 +137,10 @@ static int parse_block_error_action(const char *buf, int is_read) } } -static int drive_open(DriveInfo *dinfo) +static int drive_open(DriveInfo *dinfo, int extra_flags) { - int res = bdrv_open(dinfo->bdrv, dinfo->file, dinfo->bdrv_flags, dinfo->drv); + int res = bdrv_open(dinfo->bdrv, dinfo->file, + dinfo->bdrv_flags | extra_flags, dinfo->drv); if (res < 0) { fprintf(stderr, "qemu: could not open disk image %s: %s\n", @@ -156,7 +157,7 @@ int drives_reinit(void) if (dinfo->opened && !bdrv_is_read_only(dinfo->bdrv)) { int res; bdrv_close(dinfo->bdrv); - res = drive_open(dinfo); + res = drive_open(dinfo, BDRV_O_INVALIDATE); if (res) { fprintf(stderr, "qemu: re-open of %s failed wth error %d\n", dinfo->file, res); @@ -522,7 +523,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi, int *fatal_error) dinfo->drv = drv; dinfo->opened = 1; - if (drive_open(dinfo) < 0) { + if (drive_open(dinfo, 0) < 0) { goto error; }
Linux allows to invalidate block devices. This is needed for the incoming migration part. Signed-off-by: Juan Quintela <quintela@redhat.com> --- block.h | 2 ++ block/raw-posix.c | 24 ++++++++++++++++++++++++ blockdev.c | 9 +++++---- 3 files changed, 31 insertions(+), 4 deletions(-)