| Message ID | 20180621222143.27266-2-naravamudan@digitalocean.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 06/21 15:21, Nishanth Aravamudan wrote: > laio_init() can fail for a couple of reasons, which will lead to a NULL > pointer dereference in laio_attach_aio_context(). > > To solve this, add a aio_setup_linux_aio() function which is called > early in raw_open_common. If this fails, propagate the error up. The > signature of aio_get_linux_aio() was not modified, because it seems > preferable to return the actual errno from the possible failing > initialization calls. > > Add an assert that aio_get_linux_aio() cannot return NULL. > > Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com> > --- > Changes from v2 -> v3 (thanks to Eric Blake and Kevin Wolf for review): > > Use a boolean false rather than 0 in assignment to use_linux_aio. > Drop ending '.' from error_report() calls. > Fix typo in commit message (propogates -> propagates). > Move aio_setup_linux_aio call to raw_open_common. > > Changes from v1 -> v2 (thanks to Kevin Wolf for review): > > Rather than affect virtio-scsi/blk at all, make all the changes internal > to file-posix.c. Thanks to Kevin Wolf for the suggested change. > > block/file-posix.c | 17 ++++++++++++----- > block/linux-aio.c | 15 ++++++++++----- > include/block/aio.h | 3 +++ > include/block/raw-aio.h | 2 +- > stubs/linux-aio.c | 2 +- > util/async.c | 16 +++++++++++++--- > 6 files changed, 40 insertions(+), 15 deletions(-) > > diff --git a/block/file-posix.c b/block/file-posix.c > index 07bb061fe4..6a1714d4a8 100644 > --- a/block/file-posix.c > +++ b/block/file-posix.c > @@ -545,11 +545,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, > > #ifdef CONFIG_LINUX_AIO > /* Currently Linux does AIO only for files opened with O_DIRECT */ > - if (s->use_linux_aio && !(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 (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; > + } > + ret = aio_setup_linux_aio(bdrv_get_aio_context(bs)); > + if (ret != 0) { > + error_setg(errp, "Unable to setup native AIO context."); > + goto fail; > + } > } > #else > if (s->use_linux_aio) { > diff --git a/block/linux-aio.c b/block/linux-aio.c > index 88b8d55ec7..4d799f85fe 100644 > --- a/block/linux-aio.c > +++ b/block/linux-aio.c > @@ -470,28 +470,33 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context) > qemu_laio_poll_cb); > } > > -LinuxAioState *laio_init(void) > +int laio_init(LinuxAioState **linux_aio) > { > + int rc; > LinuxAioState *s; > > s = g_malloc0(sizeof(*s)); > - if (event_notifier_init(&s->e, false) < 0) { > + rc = event_notifier_init(&s->e, false); > + if (rc < 0) { It would be nice if the error message could distinguish this error... > goto out_free_state; > } > > - if (io_setup(MAX_EVENTS, &s->ctx) != 0) { > + rc = io_setup(MAX_EVENTS, &s->ctx); > + if (rc != 0) { ... from this one. And it also makes sense to propagate the errno back with error_setg_errno. To do this, add an "Error **errp" parameter to the function and you can keep the return type (LinuxAioState *). > goto out_close_efd; > } > > ioq_init(&s->io_q); > > - return s; > + *linux_aio = s; > + return 0; > > out_close_efd: > event_notifier_cleanup(&s->e); > out_free_state: > g_free(s); > - return NULL; > + *linux_aio = NULL; > + return rc; > } > > void laio_cleanup(LinuxAioState *s) > diff --git a/include/block/aio.h b/include/block/aio.h > index ae6f354e6c..8900516ac5 100644 > --- a/include/block/aio.h > +++ b/include/block/aio.h > @@ -381,6 +381,9 @@ GSource *aio_get_g_source(AioContext *ctx); > /* Return the ThreadPool bound to this AioContext */ > struct ThreadPool *aio_get_thread_pool(AioContext *ctx); > > +/* Setup the LinuxAioState bound to this AioContext */ > +int aio_setup_linux_aio(AioContext *ctx); And this will then need "Error **errp" as well. > + > /* Return the LinuxAioState bound to this AioContext */ > struct LinuxAioState *aio_get_linux_aio(AioContext *ctx); > > diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h > index 0e717fd475..81b90e5fc6 100644 > --- a/include/block/raw-aio.h > +++ b/include/block/raw-aio.h > @@ -43,7 +43,7 @@ > /* linux-aio.c - Linux native implementation */ > #ifdef CONFIG_LINUX_AIO > typedef struct LinuxAioState LinuxAioState; > -LinuxAioState *laio_init(void); > +int laio_init(LinuxAioState **linux_aio); > void laio_cleanup(LinuxAioState *s); > int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd, > uint64_t offset, QEMUIOVector *qiov, int type); > diff --git a/stubs/linux-aio.c b/stubs/linux-aio.c > index ed47bd443c..88ab927e35 100644 > --- a/stubs/linux-aio.c > +++ b/stubs/linux-aio.c > @@ -21,7 +21,7 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context) > abort(); > } > > -LinuxAioState *laio_init(void) > +int laio_init(LinuxAioState **linux_aio) > { > abort(); > } > diff --git a/util/async.c b/util/async.c > index 03f62787f2..ae88c931d0 100644 > --- a/util/async.c > +++ b/util/async.c > @@ -323,12 +323,22 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx) > } > > #ifdef CONFIG_LINUX_AIO > -LinuxAioState *aio_get_linux_aio(AioContext *ctx) > +int aio_setup_linux_aio(AioContext *ctx) > { > + int rc; > + rc = 0; > if (!ctx->linux_aio) { > - ctx->linux_aio = laio_init(); > - laio_attach_aio_context(ctx->linux_aio, ctx); > + rc = laio_init(&ctx->linux_aio); > + if (rc == 0) { > + laio_attach_aio_context(ctx->linux_aio, ctx); > + } > } > + return rc; > +} > + > +LinuxAioState *aio_get_linux_aio(AioContext *ctx) > +{ > + assert(ctx->linux_aio); > return ctx->linux_aio; > } > #endif > -- > 2.17.1 > Fam
On 22.06.2018 [10:21:19 +0800], Fam Zheng wrote: > On Thu, 06/21 15:21, Nishanth Aravamudan wrote: > > laio_init() can fail for a couple of reasons, which will lead to a NULL > > pointer dereference in laio_attach_aio_context(). > > > > To solve this, add a aio_setup_linux_aio() function which is called > > early in raw_open_common. If this fails, propagate the error up. The > > signature of aio_get_linux_aio() was not modified, because it seems > > preferable to return the actual errno from the possible failing > > initialization calls. > > > > Add an assert that aio_get_linux_aio() cannot return NULL. > > > > Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com> > > --- > > Changes from v2 -> v3 (thanks to Eric Blake and Kevin Wolf for review): > > > > Use a boolean false rather than 0 in assignment to use_linux_aio. > > Drop ending '.' from error_report() calls. > > Fix typo in commit message (propogates -> propagates). > > Move aio_setup_linux_aio call to raw_open_common. > > > > Changes from v1 -> v2 (thanks to Kevin Wolf for review): > > > > Rather than affect virtio-scsi/blk at all, make all the changes internal > > to file-posix.c. Thanks to Kevin Wolf for the suggested change. > > > > block/file-posix.c | 17 ++++++++++++----- > > block/linux-aio.c | 15 ++++++++++----- > > include/block/aio.h | 3 +++ > > include/block/raw-aio.h | 2 +- > > stubs/linux-aio.c | 2 +- > > util/async.c | 16 +++++++++++++--- > > 6 files changed, 40 insertions(+), 15 deletions(-) > > > > diff --git a/block/file-posix.c b/block/file-posix.c > > index 07bb061fe4..6a1714d4a8 100644 > > --- a/block/file-posix.c > > +++ b/block/file-posix.c > > @@ -545,11 +545,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, > > > > #ifdef CONFIG_LINUX_AIO > > /* Currently Linux does AIO only for files opened with O_DIRECT */ > > - if (s->use_linux_aio && !(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 (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; > > + } > > + ret = aio_setup_linux_aio(bdrv_get_aio_context(bs)); > > + if (ret != 0) { > > + error_setg(errp, "Unable to setup native AIO context."); > > + goto fail; > > + } > > } > > #else > > if (s->use_linux_aio) { > > diff --git a/block/linux-aio.c b/block/linux-aio.c > > index 88b8d55ec7..4d799f85fe 100644 > > --- a/block/linux-aio.c > > +++ b/block/linux-aio.c > > @@ -470,28 +470,33 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context) > > qemu_laio_poll_cb); > > } > > > > -LinuxAioState *laio_init(void) > > +int laio_init(LinuxAioState **linux_aio) > > { > > + int rc; > > LinuxAioState *s; > > > > s = g_malloc0(sizeof(*s)); > > - if (event_notifier_init(&s->e, false) < 0) { > > + rc = event_notifier_init(&s->e, false); > > + if (rc < 0) { > > It would be nice if the error message could distinguish this error... > > > goto out_free_state; > > } > > > > - if (io_setup(MAX_EVENTS, &s->ctx) != 0) { > > + rc = io_setup(MAX_EVENTS, &s->ctx); > > + if (rc != 0) { > > ... from this one. And it also makes sense to propagate the errno back with > error_setg_errno. > > To do this, add an "Error **errp" parameter to the function and you > can keep the return type (LinuxAioState *). Thank you for this suggestion! I will send out a v4 with this and your other feedback integrated. -Nish
diff --git a/block/file-posix.c b/block/file-posix.c index 07bb061fe4..6a1714d4a8 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -545,11 +545,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, #ifdef CONFIG_LINUX_AIO /* Currently Linux does AIO only for files opened with O_DIRECT */ - if (s->use_linux_aio && !(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 (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; + } + ret = aio_setup_linux_aio(bdrv_get_aio_context(bs)); + if (ret != 0) { + error_setg(errp, "Unable to setup native AIO context."); + goto fail; + } } #else if (s->use_linux_aio) { diff --git a/block/linux-aio.c b/block/linux-aio.c index 88b8d55ec7..4d799f85fe 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -470,28 +470,33 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context) qemu_laio_poll_cb); } -LinuxAioState *laio_init(void) +int laio_init(LinuxAioState **linux_aio) { + int rc; LinuxAioState *s; s = g_malloc0(sizeof(*s)); - if (event_notifier_init(&s->e, false) < 0) { + rc = event_notifier_init(&s->e, false); + if (rc < 0) { goto out_free_state; } - if (io_setup(MAX_EVENTS, &s->ctx) != 0) { + rc = io_setup(MAX_EVENTS, &s->ctx); + if (rc != 0) { goto out_close_efd; } ioq_init(&s->io_q); - return s; + *linux_aio = s; + return 0; out_close_efd: event_notifier_cleanup(&s->e); out_free_state: g_free(s); - return NULL; + *linux_aio = NULL; + return rc; } void laio_cleanup(LinuxAioState *s) diff --git a/include/block/aio.h b/include/block/aio.h index ae6f354e6c..8900516ac5 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -381,6 +381,9 @@ GSource *aio_get_g_source(AioContext *ctx); /* Return the ThreadPool bound to this AioContext */ struct ThreadPool *aio_get_thread_pool(AioContext *ctx); +/* Setup the LinuxAioState bound to this AioContext */ +int aio_setup_linux_aio(AioContext *ctx); + /* Return the LinuxAioState bound to this AioContext */ struct LinuxAioState *aio_get_linux_aio(AioContext *ctx); diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h index 0e717fd475..81b90e5fc6 100644 --- a/include/block/raw-aio.h +++ b/include/block/raw-aio.h @@ -43,7 +43,7 @@ /* linux-aio.c - Linux native implementation */ #ifdef CONFIG_LINUX_AIO typedef struct LinuxAioState LinuxAioState; -LinuxAioState *laio_init(void); +int laio_init(LinuxAioState **linux_aio); void laio_cleanup(LinuxAioState *s); int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd, uint64_t offset, QEMUIOVector *qiov, int type); diff --git a/stubs/linux-aio.c b/stubs/linux-aio.c index ed47bd443c..88ab927e35 100644 --- a/stubs/linux-aio.c +++ b/stubs/linux-aio.c @@ -21,7 +21,7 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context) abort(); } -LinuxAioState *laio_init(void) +int laio_init(LinuxAioState **linux_aio) { abort(); } diff --git a/util/async.c b/util/async.c index 03f62787f2..ae88c931d0 100644 --- a/util/async.c +++ b/util/async.c @@ -323,12 +323,22 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx) } #ifdef CONFIG_LINUX_AIO -LinuxAioState *aio_get_linux_aio(AioContext *ctx) +int aio_setup_linux_aio(AioContext *ctx) { + int rc; + rc = 0; if (!ctx->linux_aio) { - ctx->linux_aio = laio_init(); - laio_attach_aio_context(ctx->linux_aio, ctx); + rc = laio_init(&ctx->linux_aio); + if (rc == 0) { + laio_attach_aio_context(ctx->linux_aio, ctx); + } } + return rc; +} + +LinuxAioState *aio_get_linux_aio(AioContext *ctx) +{ + assert(ctx->linux_aio); return ctx->linux_aio; } #endif
laio_init() can fail for a couple of reasons, which will lead to a NULL pointer dereference in laio_attach_aio_context(). To solve this, add a aio_setup_linux_aio() function which is called early in raw_open_common. If this fails, propagate the error up. The signature of aio_get_linux_aio() was not modified, because it seems preferable to return the actual errno from the possible failing initialization calls. Add an assert that aio_get_linux_aio() cannot return NULL. Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com> --- Changes from v2 -> v3 (thanks to Eric Blake and Kevin Wolf for review): Use a boolean false rather than 0 in assignment to use_linux_aio. Drop ending '.' from error_report() calls. Fix typo in commit message (propogates -> propagates). Move aio_setup_linux_aio call to raw_open_common. Changes from v1 -> v2 (thanks to Kevin Wolf for review): Rather than affect virtio-scsi/blk at all, make all the changes internal to file-posix.c. Thanks to Kevin Wolf for the suggested change. block/file-posix.c | 17 ++++++++++++----- block/linux-aio.c | 15 ++++++++++----- include/block/aio.h | 3 +++ include/block/raw-aio.h | 2 +- stubs/linux-aio.c | 2 +- util/async.c | 16 +++++++++++++--- 6 files changed, 40 insertions(+), 15 deletions(-)