[Qemu-devel] [PULL 00/19] Block patches

[Qemu-devel] [PULL 00/19] Block patches

[Kevin Wolf]

The following changes since commit d3e8f95753114a827f9cd8e819b1d5cc8333f76b:

  w32: Add implementation of gmtime_r, localtime_r (2012-09-23 17:09:30 +0000)

are available in the git repository at:

  git://repo.or.cz/qemu/kevin.git for-anthony

Jeff Cody (18):
      block: correctly set the keep_read_only flag
      block: make bdrv_set_enable_write_cache() modify open_flags
      block: Framework for reopening files safely
      block: move aio initialization into a helper function
      block: move open flag parsing in raw block drivers to helper functions
      block: do not parse BDRV_O_CACHE_WB in block drivers
      block: use BDRV_O_NOCACHE instead of s->aligned_buf in raw-posix.c
      block: purge s->aligned_buf and s->aligned_buf_size from raw-posix.c
      block: raw-posix image file reopen
      block: raw image file reopen
      block: qed image file reopen
      block: qcow2 image file reopen
      block: qcow image file reopen
      block: vmdk image file reopen
      block: vdi image file reopen
      block: vpc image file reopen
      block: convert bdrv_commit() to use bdrv_reopen()
      block: remove keep_read_only flag from BlockDriverState struct

Kevin Shanahan (1):
      blockdev: preserve readonly and snapshot states across media changes

 block.c           |  299 ++++++++++++++++++++++++++++++++++++++++++++---------
 block.h           |   18 +++
 block/iscsi.c     |    4 -
 block/qcow.c      |   10 ++
 block/qcow2.c     |   10 ++
 block/qed.c       |    9 ++
 block/raw-posix.c |  225 ++++++++++++++++++++++++++++++----------
 block/raw-win32.c |   40 ++++----
 block/raw.c       |   10 ++
 block/rbd.c       |    6 -
 block/sheepdog.c  |   14 +--
 block/vdi.c       |    7 ++
 block/vmdk.c      |   35 ++++++
 block/vpc.c       |    7 ++
 block_int.h       |    9 ++-
 blockdev.c        |    2 +
 16 files changed, 563 insertions(+), 142 deletions(-)

[Qemu-devel] [PATCH 01/19] blockdev: preserve readonly and snapshot states across media changes

[Kevin Wolf]

From: Kevin Shanahan <kmshanah@disenchant.net>

If readonly=on is given at device creation time, the ->readonly flag
needs to be set in the block driver state for this device so that
readonly-ness is preserved across media changes (qmp change command).
Similarly, to preserve the snapshot property requires ->open_flags to
be correct.

Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 7c83baa..e5d450f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -527,6 +527,8 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
                      if_name[type], mediastr, unit_id);
     }
     dinfo->bdrv = bdrv_new(dinfo->id);
+    dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0;
+    dinfo->bdrv->read_only = ro;
     dinfo->devaddr = devaddr;
     dinfo->type = type;
     dinfo->bus = bus_id;
-- 
1.7.6.5

[Qemu-devel] [PATCH 02/19] block: correctly set the keep_read_only flag

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

I believe the bs->keep_read_only flag is supposed to reflect
the initial open state of the device. If the device is initially
opened R/O, then commit operations, or reopen operations changing
to R/W, are prohibited.

Currently, the keep_read_only flag is only accurate for the active
layer, and its backing file. Subsequent images end up always having
the keep_read_only flag set.

For instance, what happens now:

[  base  ]  kro = 1, ro = 1
    |
    v
[ snap-1 ]  kro = 1, ro = 1
    |
    v
[ snap-2 ]  kro = 0, ro = 1
    |
    v
[ active ]  kro = 0, ro = 0

What we want:

[  base  ]  kro = 0, ro = 1
    |
    v
[ snap-1 ]  kro = 0, ro = 1
    |
    v
[ snap-2 ]  kro = 0, ro = 1
    |
    v
[ active ]  kro = 0, ro = 0

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c |   14 +++++++-------
 block.h |    1 +
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/block.c b/block.c
index e78039b..4c0e7f5 100644
--- a/block.c
+++ b/block.c
@@ -668,7 +668,7 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
         open_flags |= BDRV_O_RDWR;
     }
 
-    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
+    bs->read_only = !(open_flags & BDRV_O_RDWR);
 
     /* Open the image, either directly or using a protocol */
     if (drv->bdrv_file_open) {
@@ -808,6 +808,12 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         goto unlink_and_fail;
     }
 
+    if (flags & BDRV_O_RDWR) {
+        flags |= BDRV_O_ALLOW_RDWR;
+    }
+
+    bs->keep_read_only = !(flags & BDRV_O_ALLOW_RDWR);
+
     /* Open the image */
     ret = bdrv_open_common(bs, filename, flags, drv);
     if (ret < 0) {
@@ -837,12 +843,6 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
             bdrv_close(bs);
             return ret;
         }
-        if (bs->is_temporary) {
-            bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
-        } else {
-            /* base image inherits from "parent" */
-            bs->backing_hd->keep_read_only = bs->keep_read_only;
-        }
     }
 
     if (!bdrv_key_required(bs)) {
diff --git a/block.h b/block.h
index 2e2be11..4d919c2 100644
--- a/block.h
+++ b/block.h
@@ -80,6 +80,7 @@ typedef struct BlockDevOps {
 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
 #define BDRV_O_INCOMING    0x0800  /* consistency hint for incoming migration */
 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
+#define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
 
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
 
-- 
1.7.6.5

[Qemu-devel] [PATCH 03/19] block: make bdrv_set_enable_write_cache() modify open_flags

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

bdrv_set_enable_write_cache() sets the bs->enable_write_cache flag,
but without the flag recorded in bs->open_flags, then next time
a reopen() is performed the enable_write_cache setting may be
inadvertently lost.

This will set the flag in open_flags, so it is preserved across
reopens.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/block.c b/block.c
index 4c0e7f5..458bcc9 100644
--- a/block.c
+++ b/block.c
@@ -2168,6 +2168,13 @@ int bdrv_enable_write_cache(BlockDriverState *bs)
 void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
 {
     bs->enable_write_cache = wce;
+
+    /* so a reopen() will preserve wce */
+    if (wce) {
+        bs->open_flags |= BDRV_O_CACHE_WB;
+    } else {
+        bs->open_flags &= ~BDRV_O_CACHE_WB;
+    }
 }
 
 int bdrv_is_encrypted(BlockDriverState *bs)
-- 
1.7.6.5

[Qemu-devel] [PATCH 04/19] block: Framework for reopening files safely

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

This is based on Supriya Kannery's bdrv_reopen() patch series.

This provides a transactional method to reopen multiple
images files safely.

Image files are queue for reopen via bdrv_reopen_queue(), and the
reopen occurs when bdrv_reopen_multiple() is called.  Changes are
staged in bdrv_reopen_prepare() and in the equivalent driver level
functions.  If any of the staged images fails a prepare, then all
of the images left untouched, and the staged changes for each image
abandoned.

Block drivers are passed a reopen state structure, that contains:
    * BDS to reopen
    * flags for the reopen
    * opaque pointer for any driver-specific data that needs to be
      persistent from _prepare to _commit/_abort
    * reopen queue pointer, if the driver needs to queue additional
      BDS for a reopen

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c     |  232 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 block.h     |   17 +++++
 block_int.h |    8 ++
 3 files changed, 257 insertions(+), 0 deletions(-)

diff --git a/block.c b/block.c
index 458bcc9..c7c1a3b 100644
--- a/block.c
+++ b/block.c
@@ -863,6 +863,238 @@ unlink_and_fail:
     return ret;
 }
 
+typedef struct BlockReopenQueueEntry {
+     bool prepared;
+     BDRVReopenState state;
+     QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry;
+} BlockReopenQueueEntry;
+
+/*
+ * Adds a BlockDriverState to a simple queue for an atomic, transactional
+ * reopen of multiple devices.
+ *
+ * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
+ * already performed, or alternatively may be NULL a new BlockReopenQueue will
+ * be created and initialized. This newly created BlockReopenQueue should be
+ * passed back in for subsequent calls that are intended to be of the same
+ * atomic 'set'.
+ *
+ * bs is the BlockDriverState to add to the reopen queue.
+ *
+ * flags contains the open flags for the associated bs
+ *
+ * returns a pointer to bs_queue, which is either the newly allocated
+ * bs_queue, or the existing bs_queue being used.
+ *
+ */
+BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
+                                    BlockDriverState *bs, int flags)
+{
+    assert(bs != NULL);
+
+    BlockReopenQueueEntry *bs_entry;
+    if (bs_queue == NULL) {
+        bs_queue = g_new0(BlockReopenQueue, 1);
+        QSIMPLEQ_INIT(bs_queue);
+    }
+
+    if (bs->file) {
+        bdrv_reopen_queue(bs_queue, bs->file, flags);
+    }
+
+    bs_entry = g_new0(BlockReopenQueueEntry, 1);
+    QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry);
+
+    bs_entry->state.bs = bs;
+    bs_entry->state.flags = flags;
+
+    return bs_queue;
+}
+
+/*
+ * Reopen multiple BlockDriverStates atomically & transactionally.
+ *
+ * The queue passed in (bs_queue) must have been built up previous
+ * via bdrv_reopen_queue().
+ *
+ * Reopens all BDS specified in the queue, with the appropriate
+ * flags.  All devices are prepared for reopen, and failure of any
+ * device will cause all device changes to be abandonded, and intermediate
+ * data cleaned up.
+ *
+ * If all devices prepare successfully, then the changes are committed
+ * to all devices.
+ *
+ */
+int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
+{
+    int ret = -1;
+    BlockReopenQueueEntry *bs_entry, *next;
+    Error *local_err = NULL;
+
+    assert(bs_queue != NULL);
+
+    bdrv_drain_all();
+
+    QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
+        if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
+            error_propagate(errp, local_err);
+            goto cleanup;
+        }
+        bs_entry->prepared = true;
+    }
+
+    /* If we reach this point, we have success and just need to apply the
+     * changes
+     */
+    QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
+        bdrv_reopen_commit(&bs_entry->state);
+    }
+
+    ret = 0;
+
+cleanup:
+    QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
+        if (ret && bs_entry->prepared) {
+            bdrv_reopen_abort(&bs_entry->state);
+        }
+        g_free(bs_entry);
+    }
+    g_free(bs_queue);
+    return ret;
+}
+
+
+/* Reopen a single BlockDriverState with the specified flags. */
+int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
+{
+    int ret = -1;
+    Error *local_err = NULL;
+    BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, bdrv_flags);
+
+    ret = bdrv_reopen_multiple(queue, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+    }
+    return ret;
+}
+
+
+/*
+ * Prepares a BlockDriverState for reopen. All changes are staged in the
+ * 'opaque' field of the BDRVReopenState, which is used and allocated by
+ * the block driver layer .bdrv_reopen_prepare()
+ *
+ * bs is the BlockDriverState to reopen
+ * flags are the new open flags
+ * queue is the reopen queue
+ *
+ * Returns 0 on success, non-zero on error.  On error errp will be set
+ * as well.
+ *
+ * On failure, bdrv_reopen_abort() will be called to clean up any data.
+ * It is the responsibility of the caller to then call the abort() or
+ * commit() for any other BDS that have been left in a prepare() state
+ *
+ */
+int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
+                        Error **errp)
+{
+    int ret = -1;
+    Error *local_err = NULL;
+    BlockDriver *drv;
+
+    assert(reopen_state != NULL);
+    assert(reopen_state->bs->drv != NULL);
+    drv = reopen_state->bs->drv;
+
+    /* if we are to stay read-only, do not allow permission change
+     * to r/w */
+    if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) &&
+        reopen_state->flags & BDRV_O_RDWR) {
+        error_set(errp, QERR_DEVICE_IS_READ_ONLY,
+                  reopen_state->bs->device_name);
+        goto error;
+    }
+
+
+    ret = bdrv_flush(reopen_state->bs);
+    if (ret) {
+        error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive",
+                  strerror(-ret));
+        goto error;
+    }
+
+    if (drv->bdrv_reopen_prepare) {
+        ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
+        if (ret) {
+            if (local_err != NULL) {
+                error_propagate(errp, local_err);
+            } else {
+                error_set(errp, QERR_OPEN_FILE_FAILED,
+                          reopen_state->bs->filename);
+            }
+            goto error;
+        }
+    } else {
+        /* It is currently mandatory to have a bdrv_reopen_prepare()
+         * handler for each supported drv. */
+        error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
+                  drv->format_name, reopen_state->bs->device_name,
+                 "reopening of file");
+        ret = -1;
+        goto error;
+    }
+
+    ret = 0;
+
+error:
+    return ret;
+}
+
+/*
+ * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
+ * makes them final by swapping the staging BlockDriverState contents into
+ * the active BlockDriverState contents.
+ */
+void bdrv_reopen_commit(BDRVReopenState *reopen_state)
+{
+    BlockDriver *drv;
+
+    assert(reopen_state != NULL);
+    drv = reopen_state->bs->drv;
+    assert(drv != NULL);
+
+    /* If there are any driver level actions to take */
+    if (drv->bdrv_reopen_commit) {
+        drv->bdrv_reopen_commit(reopen_state);
+    }
+
+    /* set BDS specific flags now */
+    reopen_state->bs->open_flags         = reopen_state->flags;
+    reopen_state->bs->enable_write_cache = !!(reopen_state->flags &
+                                              BDRV_O_CACHE_WB);
+    reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
+}
+
+/*
+ * Abort the reopen, and delete and free the staged changes in
+ * reopen_state
+ */
+void bdrv_reopen_abort(BDRVReopenState *reopen_state)
+{
+    BlockDriver *drv;
+
+    assert(reopen_state != NULL);
+    drv = reopen_state->bs->drv;
+    assert(drv != NULL);
+
+    if (drv->bdrv_reopen_abort) {
+        drv->bdrv_reopen_abort(reopen_state);
+    }
+}
+
+
 void bdrv_close(BlockDriverState *bs)
 {
     bdrv_flush(bs);
diff --git a/block.h b/block.h
index 4d919c2..b1095d8 100644
--- a/block.h
+++ b/block.h
@@ -97,6 +97,15 @@ typedef enum {
     BDRV_ACTION_REPORT, BDRV_ACTION_IGNORE, BDRV_ACTION_STOP
 } BlockQMPEventAction;
 
+typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
+
+typedef struct BDRVReopenState {
+    BlockDriverState *bs;
+    int flags;
+    void *opaque;
+} BDRVReopenState;
+
+
 void bdrv_iostatus_enable(BlockDriverState *bs);
 void bdrv_iostatus_reset(BlockDriverState *bs);
 void bdrv_iostatus_disable(BlockDriverState *bs);
@@ -131,6 +140,14 @@ int bdrv_parse_cache_flags(const char *mode, int *flags);
 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags);
 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
               BlockDriver *drv);
+BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
+                                    BlockDriverState *bs, int flags);
+int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
+int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
+int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
+                        BlockReopenQueue *queue, Error **errp);
+void bdrv_reopen_commit(BDRVReopenState *reopen_state);
+void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 void bdrv_close(BlockDriverState *bs);
 int bdrv_attach_dev(BlockDriverState *bs, void *dev);
 void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);
diff --git a/block_int.h b/block_int.h
index 4452f6f..22b3d93 100644
--- a/block_int.h
+++ b/block_int.h
@@ -139,6 +139,13 @@ struct BlockDriver {
     int instance_size;
     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
     int (*bdrv_probe_device)(const char *filename);
+
+    /* For handling image reopen for split or non-split files */
+    int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
+                               BlockReopenQueue *queue, Error **errp);
+    void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
+    void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
+
     int (*bdrv_open)(BlockDriverState *bs, int flags);
     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
@@ -336,6 +343,7 @@ struct BlockDriverState {
 
     /* long-running background operation */
     BlockJob *job;
+
 };
 
 int get_tmp_filename(char *filename, int size);
-- 
1.7.6.5

[Qemu-devel] [PATCH 05/19] block: move aio initialization into a helper function

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

Move AIO initialization for raw-posix block driver into a helper function.

In addition to just code motion, the aio_ctx pointer is checked for NULL,
prior to calling laio_init(), to make sure laio_init() is only run once.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw-posix.c |   53 +++++++++++++++++++++++++++++++++++------------------
 1 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 6be20b1..5981d04 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -185,6 +185,38 @@ static int raw_normalize_devicepath(const char **filename)
 }
 #endif
 
+#ifdef CONFIG_LINUX_AIO
+static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)
+{
+    int ret = -1;
+    assert(aio_ctx != NULL);
+    assert(use_aio != NULL);
+    /*
+     * Currently Linux do AIO only for files opened with O_DIRECT
+     * specified so check NOCACHE flag too
+     */
+    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
+                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
+
+        /* if non-NULL, laio_init() has already been run */
+        if (*aio_ctx == NULL) {
+            *aio_ctx = laio_init();
+            if (!*aio_ctx) {
+                goto error;
+            }
+        }
+        *use_aio = 1;
+    } else {
+        *use_aio = 0;
+    }
+
+    ret = 0;
+
+error:
+    return ret;
+}
+#endif
+
 static int raw_open_common(BlockDriverState *bs, const char *filename,
                            int bdrv_flags, int open_flags)
 {
@@ -240,25 +272,10 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
     }
 
 #ifdef CONFIG_LINUX_AIO
-    /*
-     * Currently Linux do AIO only for files opened with O_DIRECT
-     * specified so check NOCACHE flag too
-     */
-    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
-                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
-
-        s->aio_ctx = laio_init();
-        if (!s->aio_ctx) {
-            goto out_free_buf;
-        }
-        s->use_aio = 1;
-    } else
-#endif
-    {
-#ifdef CONFIG_LINUX_AIO
-        s->use_aio = 0;
-#endif
+    if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) {
+        goto out_close;
     }
+#endif
 
 #ifdef CONFIG_XFS
     if (platform_test_xfs_fd(s->fd)) {
-- 
1.7.6.5

[Qemu-devel] [PATCH 06/19] block: move open flag parsing in raw block drivers to helper functions

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

Code motion, to move parsing of open flags into a helper function.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw-posix.c |   38 ++++++++++++++++++++++++--------------
 block/raw-win32.c |   43 +++++++++++++++++++++++--------------------
 2 files changed, 47 insertions(+), 34 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 5981d04..155205f 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -185,6 +185,28 @@ static int raw_normalize_devicepath(const char **filename)
 }
 #endif
 
+static void raw_parse_flags(int bdrv_flags, int *open_flags)
+{
+    assert(open_flags != NULL);
+
+    *open_flags |= O_BINARY;
+    *open_flags &= ~O_ACCMODE;
+    if (bdrv_flags & BDRV_O_RDWR) {
+        *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;
+    }
+    if (!(bdrv_flags & BDRV_O_CACHE_WB)) {
+        *open_flags |= O_DSYNC;
+    }
+}
+
 #ifdef CONFIG_LINUX_AIO
 static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)
 {
@@ -228,20 +250,8 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
         return ret;
     }
 
-    s->open_flags = open_flags | O_BINARY;
-    s->open_flags &= ~O_ACCMODE;
-    if (bdrv_flags & BDRV_O_RDWR) {
-        s->open_flags |= O_RDWR;
-    } else {
-        s->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))
-        s->open_flags |= O_DIRECT;
-    if (!(bdrv_flags & BDRV_O_CACHE_WB))
-        s->open_flags |= O_DSYNC;
+    s->open_flags = open_flags;
+    raw_parse_flags(bdrv_flags, &s->open_flags);
 
     s->fd = -1;
     fd = qemu_open(filename, s->open_flags, 0644);
diff --git a/block/raw-win32.c b/block/raw-win32.c
index c56bf83..335c06a 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -77,6 +77,26 @@ static int set_sparse(int fd)
 				 NULL, 0, NULL, 0, &returned, NULL);
 }
 
+static void raw_parse_flags(int flags, int *access_flags, DWORD *overlapped)
+{
+    assert(access_flags != NULL);
+    assert(overlapped != NULL);
+
+    if (flags & BDRV_O_RDWR) {
+        *access_flags = GENERIC_READ | GENERIC_WRITE;
+    } else {
+        *access_flags = GENERIC_READ;
+    }
+
+    *overlapped = FILE_ATTRIBUTE_NORMAL;
+    if (flags & BDRV_O_NOCACHE) {
+        *overlapped |= FILE_FLAG_NO_BUFFERING;
+    }
+    if (!(flags & BDRV_O_CACHE_WB)) {
+        *overlapped |= FILE_FLAG_WRITE_THROUGH;
+    }
+}
+
 static int raw_open(BlockDriverState *bs, const char *filename, int flags)
 {
     BDRVRawState *s = bs->opaque;
@@ -85,17 +105,8 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags)
 
     s->type = FTYPE_FILE;
 
-    if (flags & BDRV_O_RDWR) {
-        access_flags = GENERIC_READ | GENERIC_WRITE;
-    } else {
-        access_flags = GENERIC_READ;
-    }
+    raw_parse_flags(flags, &access_flags, &overlapped);
 
-    overlapped = FILE_ATTRIBUTE_NORMAL;
-    if (flags & BDRV_O_NOCACHE)
-        overlapped |= FILE_FLAG_NO_BUFFERING;
-    if (!(flags & BDRV_O_CACHE_WB))
-        overlapped |= FILE_FLAG_WRITE_THROUGH;
     s->hfile = CreateFile(filename, access_flags,
                           FILE_SHARE_READ, NULL,
                           OPEN_EXISTING, overlapped, NULL);
@@ -374,18 +385,10 @@ static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
     }
     s->type = find_device_type(bs, filename);
 
-    if (flags & BDRV_O_RDWR) {
-        access_flags = GENERIC_READ | GENERIC_WRITE;
-    } else {
-        access_flags = GENERIC_READ;
-    }
+    raw_parse_flags(flags, &access_flags, &overlapped);
+
     create_flags = OPEN_EXISTING;
 
-    overlapped = FILE_ATTRIBUTE_NORMAL;
-    if (flags & BDRV_O_NOCACHE)
-        overlapped |= FILE_FLAG_NO_BUFFERING;
-    if (!(flags & BDRV_O_CACHE_WB))
-        overlapped |= FILE_FLAG_WRITE_THROUGH;
     s->hfile = CreateFile(filename, access_flags,
                           FILE_SHARE_READ, NULL,
                           create_flags, overlapped, NULL);
-- 
1.7.6.5

[Qemu-devel] [PATCH 07/19] block: do not parse BDRV_O_CACHE_WB in block drivers

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

Block drivers should ignore BDRV_O_CACHE_WB in .bdrv_open flags,
and in the bs->open_flags.

This patch removes the code, leaving the behaviour behind as if
BDRV_O_CACHE_WB was set.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/iscsi.c     |    4 ----
 block/raw-posix.c |    3 ---
 block/raw-win32.c |    3 ---
 block/rbd.c       |    6 ------
 block/sheepdog.c  |   14 ++++++--------
 5 files changed, 6 insertions(+), 24 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 0b96165..70cf700 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -268,10 +268,6 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
     acb->task->xfer_dir = SCSI_XFER_WRITE;
     acb->task->cdb_size = 16;
     acb->task->cdb[0] = 0x8a;
-    if (!(bs->open_flags & BDRV_O_CACHE_WB)) {
-        /* set FUA on writes when cache mode is write through */
-        acb->task->cdb[1] |= 0x04;
-    }
     lba = sector_qemu2lun(sector_num, iscsilun);
     *(uint32_t *)&acb->task->cdb[2]  = htonl(lba >> 32);
     *(uint32_t *)&acb->task->cdb[6]  = htonl(lba & 0xffffffff);
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 155205f..288e7ff 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -202,9 +202,6 @@ static void raw_parse_flags(int bdrv_flags, int *open_flags)
     if ((bdrv_flags & BDRV_O_NOCACHE)) {
         *open_flags |= O_DIRECT;
     }
-    if (!(bdrv_flags & BDRV_O_CACHE_WB)) {
-        *open_flags |= O_DSYNC;
-    }
 }
 
 #ifdef CONFIG_LINUX_AIO
diff --git a/block/raw-win32.c b/block/raw-win32.c
index 335c06a..78c8306 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -92,9 +92,6 @@ static void raw_parse_flags(int flags, int *access_flags, DWORD *overlapped)
     if (flags & BDRV_O_NOCACHE) {
         *overlapped |= FILE_FLAG_NO_BUFFERING;
     }
-    if (!(flags & BDRV_O_CACHE_WB)) {
-        *overlapped |= FILE_FLAG_WRITE_THROUGH;
-    }
 }
 
 static int raw_open(BlockDriverState *bs, const char *filename, int flags)
diff --git a/block/rbd.c b/block/rbd.c
index 5a0f79f..015a9db 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -487,12 +487,6 @@ static int qemu_rbd_open(BlockDriverState *bs, const char *filename, int flags)
         rados_conf_set(s->cluster, "rbd_cache", "false");
     } else {
         rados_conf_set(s->cluster, "rbd_cache", "true");
-        if (!(flags & BDRV_O_CACHE_WB)) {
-            r = rados_conf_set(s->cluster, "rbd_cache_max_dirty", "0");
-            if (r < 0) {
-                rados_conf_set(s->cluster, "rbd_cache", "false");
-            }
-        }
     }
 
     if (strstr(conf, "conf=") == NULL) {
diff --git a/block/sheepdog.c b/block/sheepdog.c
index e0753ee..4742f8a 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -1114,14 +1114,12 @@ static int sd_open(BlockDriverState *bs, const char *filename, int flags)
         goto out;
     }
 
-    if (flags & BDRV_O_CACHE_WB) {
-        s->cache_enabled = 1;
-        s->flush_fd = connect_to_sdog(s->addr, s->port);
-        if (s->flush_fd < 0) {
-            error_report("failed to connect");
-            ret = s->flush_fd;
-            goto out;
-        }
+    s->cache_enabled = 1;
+    s->flush_fd = connect_to_sdog(s->addr, s->port);
+    if (s->flush_fd < 0) {
+        error_report("failed to connect");
+        ret = s->flush_fd;
+        goto out;
     }
 
     if (snapid || tag[0] != '\0') {
-- 
1.7.6.5

[Qemu-devel] [PATCH 08/19] block: use BDRV_O_NOCACHE instead of s->aligned_buf in raw-posix.c

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

Rather than check for a non-NULL aligned_buf to determine if
raw_aio_submit needs to check for alignment, check for the presence
of BDRV_O_NOCACHE in the bs->open_flags.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw-posix.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 288e7ff..1e727eb 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -354,7 +354,7 @@ static BlockDriverAIOCB *raw_aio_submit(BlockDriverState *bs,
      * boundary.  Check if this is the case or tell the low-level
      * driver that it needs to copy the buffer.
      */
-    if (s->aligned_buf) {
+    if ((bs->open_flags & BDRV_O_NOCACHE)) {
         if (!qiov_is_aligned(bs, qiov)) {
             type |= QEMU_AIO_MISALIGNED;
 #ifdef CONFIG_LINUX_AIO
-- 
1.7.6.5

[Qemu-devel] [PATCH 09/19] block: purge s->aligned_buf and s->aligned_buf_size from raw-posix.c

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

The aligned_buf pointer and aligned_buf size are no longer used in
raw_posix.c, so remove all references to them.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw-posix.c |   21 +--------------------
 1 files changed, 1 insertions(+), 20 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 1e727eb..0ffb3d0 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -133,8 +133,6 @@ typedef struct BDRVRawState {
     int use_aio;
     void *aio_ctx;
 #endif
-    uint8_t *aligned_buf;
-    unsigned aligned_buf_size;
 #ifdef CONFIG_XFS
     bool is_xfs : 1;
 #endif
@@ -259,23 +257,10 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
         return ret;
     }
     s->fd = fd;
-    s->aligned_buf = NULL;
-
-    if ((bdrv_flags & BDRV_O_NOCACHE)) {
-        /*
-         * Allocate a buffer for read/modify/write cycles.  Chose the size
-         * pessimistically as we don't know the block size yet.
-         */
-        s->aligned_buf_size = 32 * MAX_BLOCKSIZE;
-        s->aligned_buf = qemu_memalign(MAX_BLOCKSIZE, s->aligned_buf_size);
-        if (s->aligned_buf == NULL) {
-            goto out_close;
-        }
-    }
 
     /* We're falling back to POSIX AIO in some cases so init always */
     if (paio_init() < 0) {
-        goto out_free_buf;
+        goto out_close;
     }
 
 #ifdef CONFIG_LINUX_AIO
@@ -292,8 +277,6 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
 
     return 0;
 
-out_free_buf:
-    qemu_vfree(s->aligned_buf);
 out_close:
     qemu_close(fd);
     return -errno;
@@ -402,8 +385,6 @@ static void raw_close(BlockDriverState *bs)
     if (s->fd >= 0) {
         qemu_close(s->fd);
         s->fd = -1;
-        if (s->aligned_buf != NULL)
-            qemu_vfree(s->aligned_buf);
     }
 }
 
-- 
1.7.6.5

[Qemu-devel] [PATCH 10/19] block: raw-posix image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

This is derived from the Supriya Kannery's reopen patches.

This contains the raw-posix driver changes for the bdrv_reopen_*
functions.  All changes are staged into a temporary scratch buffer
during the prepare() stage, and copied over to the live structure
during commit().  Upon abort(), all changes are abandoned, and the
live structures are unmodified.

The _prepare() will create an extra fd - either by means of a dup,
if possible, or opening a new fd if not (for instance, access
control changes).  Upon _commit(), the original fd is closed and
the new fd is used.  Upon _abort(), the duplicate/new fd is closed.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw-posix.c |  114 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 114 insertions(+), 0 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 0ffb3d0..28d439f 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -138,6 +138,14 @@ typedef struct BDRVRawState {
 #endif
 } BDRVRawState;
 
+typedef struct BDRVRawReopenState {
+    int fd;
+    int open_flags;
+#ifdef CONFIG_LINUX_AIO
+    int use_aio;
+#endif
+} BDRVRawReopenState;
+
 static int fd_open(BlockDriverState *bs);
 static int64_t raw_getlength(BlockDriverState *bs);
 
@@ -290,6 +298,109 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags)
     return raw_open_common(bs, filename, flags, 0);
 }
 
+static int raw_reopen_prepare(BDRVReopenState *state,
+                              BlockReopenQueue *queue, Error **errp)
+{
+    BDRVRawState *s;
+    BDRVRawReopenState *raw_s;
+    int ret = 0;
+
+    assert(state != NULL);
+    assert(state->bs != NULL);
+
+    s = state->bs->opaque;
+
+    state->opaque = g_malloc0(sizeof(BDRVRawReopenState));
+    raw_s = state->opaque;
+
+#ifdef CONFIG_LINUX_AIO
+    raw_s->use_aio = s->use_aio;
+
+    /* we can use s->aio_ctx instead of a copy, because the use_aio flag is
+     * valid in the 'false' condition even if aio_ctx is set, and raw_set_aio()
+     * won't override aio_ctx if aio_ctx is non-NULL */
+    if (raw_set_aio(&s->aio_ctx, &raw_s->use_aio, state->flags)) {
+        return -1;
+    }
+#endif
+
+    raw_parse_flags(state->flags, &raw_s->open_flags);
+
+    raw_s->fd = -1;
+
+    int fcntl_flags = O_APPEND | O_ASYNC | O_NONBLOCK;
+#ifdef O_NOATIME
+    fcntl_flags |= O_NOATIME;
+#endif
+
+    if ((raw_s->open_flags & ~fcntl_flags) == (s->open_flags & ~fcntl_flags)) {
+        /* dup the original fd */
+        /* TODO: use qemu fcntl wrapper */
+#ifdef F_DUPFD_CLOEXEC
+        raw_s->fd = fcntl(s->fd, F_DUPFD_CLOEXEC, 0);
+#else
+        raw_s->fd = dup(s->fd);
+        if (raw_s->fd != -1) {
+            qemu_set_cloexec(raw_s->fd);
+        }
+#endif
+        if (raw_s->fd >= 0) {
+            ret = fcntl_setfl(raw_s->fd, raw_s->open_flags);
+            if (ret) {
+                qemu_close(raw_s->fd);
+                raw_s->fd = -1;
+            }
+        }
+    }
+
+    /* If we cannot use fcntl, or fcntl failed, fall back to qemu_open() */
+    if (raw_s->fd == -1) {
+        assert(!(raw_s->open_flags & O_CREAT));
+        raw_s->fd = qemu_open(state->bs->filename, raw_s->open_flags);
+        if (raw_s->fd == -1) {
+            ret = -1;
+        }
+    }
+    return ret;
+}
+
+
+static void raw_reopen_commit(BDRVReopenState *state)
+{
+    BDRVRawReopenState *raw_s = state->opaque;
+    BDRVRawState *s = state->bs->opaque;
+
+    s->open_flags = raw_s->open_flags;
+
+    qemu_close(s->fd);
+    s->fd = raw_s->fd;
+#ifdef CONFIG_LINUX_AIO
+    s->use_aio = raw_s->use_aio;
+#endif
+
+    g_free(state->opaque);
+    state->opaque = NULL;
+}
+
+
+static void raw_reopen_abort(BDRVReopenState *state)
+{
+    BDRVRawReopenState *raw_s = state->opaque;
+
+     /* nothing to do if NULL, we didn't get far enough */
+    if (raw_s == NULL) {
+        return;
+    }
+
+    if (raw_s->fd >= 0) {
+        qemu_close(raw_s->fd);
+        raw_s->fd = -1;
+    }
+    g_free(state->opaque);
+    state->opaque = NULL;
+}
+
+
 /* XXX: use host sector size if necessary with:
 #ifdef DIOCGSECTORSIZE
         {
@@ -740,6 +851,9 @@ static BlockDriver bdrv_file = {
     .instance_size = sizeof(BDRVRawState),
     .bdrv_probe = NULL, /* no probe for protocols */
     .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_create = raw_create,
     .bdrv_co_discard = raw_co_discard,
-- 
1.7.6.5

[Qemu-devel] [PATCH 11/19] block: raw image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

These are the stubs for the file reopen drivers for the raw format.

There is currently nothing that needs to be done by the raw driver
in reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/block/raw.c b/block/raw.c
index ff34ea4..253e949 100644
--- a/block/raw.c
+++ b/block/raw.c
@@ -9,6 +9,14 @@ static int raw_open(BlockDriverState *bs, int flags)
     return 0;
 }
 
+/* We have nothing to do for raw reopen, stubs just return
+ * success */
+static int raw_reopen_prepare(BDRVReopenState *state,
+                              BlockReopenQueue *queue,  Error **errp)
+{
+    return 0;
+}
+
 static int coroutine_fn raw_co_readv(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, QEMUIOVector *qiov)
 {
@@ -115,6 +123,8 @@ static BlockDriver bdrv_raw = {
     .bdrv_open          = raw_open,
     .bdrv_close         = raw_close,
 
+    .bdrv_reopen_prepare  = raw_reopen_prepare,
+
     .bdrv_co_readv          = raw_co_readv,
     .bdrv_co_writev         = raw_co_writev,
     .bdrv_co_is_allocated   = raw_co_is_allocated,
-- 
1.7.6.5

[Qemu-devel] [PATCH 12/19] block: qed image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

These are the stubs for the file reopen drivers for the qed format.

There is currently nothing that needs to be done by the qed driver
in reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qed.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/block/qed.c b/block/qed.c
index 21cb239..6c182ca 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -505,6 +505,14 @@ out:
     return ret;
 }
 
+/* We have nothing to do for QED reopen, stubs just return
+ * success */
+static int bdrv_qed_reopen_prepare(BDRVReopenState *state,
+                                   BlockReopenQueue *queue, Error **errp)
+{
+    return 0;
+}
+
 static void bdrv_qed_close(BlockDriverState *bs)
 {
     BDRVQEDState *s = bs->opaque;
@@ -1564,6 +1572,7 @@ static BlockDriver bdrv_qed = {
     .bdrv_rebind              = bdrv_qed_rebind,
     .bdrv_open                = bdrv_qed_open,
     .bdrv_close               = bdrv_qed_close,
+    .bdrv_reopen_prepare      = bdrv_qed_reopen_prepare,
     .bdrv_create              = bdrv_qed_create,
     .bdrv_co_is_allocated     = bdrv_qed_co_is_allocated,
     .bdrv_make_empty          = bdrv_qed_make_empty,
-- 
1.7.6.5

[Qemu-devel] [PATCH 13/19] block: qcow2 image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

These are the stubs for the file reopen drivers for the qcow2 format.

There is currently nothing that needs to be done by the qcow2 driver
in reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 8f183f1..aa5e603 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -52,6 +52,7 @@ typedef struct {
     uint32_t magic;
     uint32_t len;
 } QCowExtension;
+
 #define  QCOW2_EXT_MAGIC_END 0
 #define  QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
 #define  QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
@@ -558,6 +559,14 @@ static int qcow2_set_key(BlockDriverState *bs, const char *key)
     return 0;
 }
 
+/* We have nothing to do for QCOW2 reopen, stubs just return
+ * success */
+static int qcow2_reopen_prepare(BDRVReopenState *state,
+                                BlockReopenQueue *queue, Error **errp)
+{
+    return 0;
+}
+
 static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs,
         int64_t sector_num, int nb_sectors, int *pnum)
 {
@@ -1679,6 +1688,7 @@ static BlockDriver bdrv_qcow2 = {
     .bdrv_probe         = qcow2_probe,
     .bdrv_open          = qcow2_open,
     .bdrv_close         = qcow2_close,
+    .bdrv_reopen_prepare  = qcow2_reopen_prepare,
     .bdrv_create        = qcow2_create,
     .bdrv_co_is_allocated = qcow2_co_is_allocated,
     .bdrv_set_key       = qcow2_set_key,
-- 
1.7.6.5

[Qemu-devel] [PATCH 14/19] block: qcow image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

These are the stubs for the file reopen drivers for the qcow format.

There is currently nothing that needs to be done by the qcow driver
in reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/block/qcow.c b/block/qcow.c
index 7b5ab87..b239c82 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -197,6 +197,15 @@ static int qcow_open(BlockDriverState *bs, int flags)
     return ret;
 }
 
+
+/* We have nothing to do for QCOW reopen, stubs just return
+ * success */
+static int qcow_reopen_prepare(BDRVReopenState *state,
+                               BlockReopenQueue *queue, Error **errp)
+{
+    return 0;
+}
+
 static int qcow_set_key(BlockDriverState *bs, const char *key)
 {
     BDRVQcowState *s = bs->opaque;
@@ -868,6 +877,7 @@ static BlockDriver bdrv_qcow = {
     .bdrv_probe		= qcow_probe,
     .bdrv_open		= qcow_open,
     .bdrv_close		= qcow_close,
+    .bdrv_reopen_prepare = qcow_reopen_prepare,
     .bdrv_create	= qcow_create,
 
     .bdrv_co_readv          = qcow_co_readv,
-- 
1.7.6.5

[Qemu-devel] [PATCH 15/19] block: vmdk image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

This patch supports reopen for VMDK image files.  VMDK extents are added
to the existing reopen queue, so that the transactional model of reopen
is maintained with multiple image files.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vmdk.c |   35 +++++++++++++++++++++++++++++++++++
 1 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index bba4c61..f2e861b 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -300,6 +300,40 @@ static int vmdk_is_cid_valid(BlockDriverState *bs)
     return 1;
 }
 
+/* Queue extents, if any, for reopen() */
+static int vmdk_reopen_prepare(BDRVReopenState *state,
+                               BlockReopenQueue *queue, Error **errp)
+{
+    BDRVVmdkState *s;
+    int ret = -1;
+    int i;
+    VmdkExtent *e;
+
+    assert(state != NULL);
+    assert(state->bs != NULL);
+
+    if (queue == NULL) {
+        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
+                 "No reopen queue for VMDK extents");
+        goto exit;
+    }
+
+    s = state->bs->opaque;
+
+    assert(s != NULL);
+
+    for (i = 0; i < s->num_extents; i++) {
+        e = &s->extents[i];
+        if (e->file != state->bs->file) {
+            bdrv_reopen_queue(queue, e->file, state->flags);
+        }
+    }
+    ret = 0;
+
+exit:
+    return ret;
+}
+
 static int vmdk_parent_open(BlockDriverState *bs)
 {
     char *p_name;
@@ -1646,6 +1680,7 @@ static BlockDriver bdrv_vmdk = {
     .instance_size  = sizeof(BDRVVmdkState),
     .bdrv_probe     = vmdk_probe,
     .bdrv_open      = vmdk_open,
+    .bdrv_reopen_prepare = vmdk_reopen_prepare,
     .bdrv_read      = vmdk_co_read,
     .bdrv_write     = vmdk_co_write,
     .bdrv_close     = vmdk_close,
-- 
1.7.6.5

[Qemu-devel] [PATCH 16/19] block: vdi image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

There is currently nothing that needs to be done for VDI reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vdi.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/block/vdi.c b/block/vdi.c
index 550cf58..f35b12e 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -454,6 +454,12 @@ static int vdi_open(BlockDriverState *bs, int flags)
     return -1;
 }
 
+static int vdi_reopen_prepare(BDRVReopenState *state,
+                              BlockReopenQueue *queue, Error **errp)
+{
+    return 0;
+}
+
 static int coroutine_fn vdi_co_is_allocated(BlockDriverState *bs,
         int64_t sector_num, int nb_sectors, int *pnum)
 {
@@ -761,6 +767,7 @@ static BlockDriver bdrv_vdi = {
     .bdrv_probe = vdi_probe,
     .bdrv_open = vdi_open,
     .bdrv_close = vdi_close,
+    .bdrv_reopen_prepare = vdi_reopen_prepare,
     .bdrv_create = vdi_create,
     .bdrv_co_is_allocated = vdi_co_is_allocated,
     .bdrv_make_empty = vdi_make_empty,
-- 
1.7.6.5

[Qemu-devel] [PATCH 17/19] block: vpc image file reopen

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

There is currently nothing that needs to be done for VPC image
file reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vpc.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/block/vpc.c b/block/vpc.c
index c0b82c4..b6bf52f 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -265,6 +265,12 @@ static int vpc_open(BlockDriverState *bs, int flags)
     return err;
 }
 
+static int vpc_reopen_prepare(BDRVReopenState *state,
+                              BlockReopenQueue *queue, Error **errp)
+{
+    return 0;
+}
+
 /*
  * Returns the absolute byte offset of the given sector in the image file.
  * If the sector is not allocated, -1 is returned instead.
@@ -783,6 +789,7 @@ static BlockDriver bdrv_vpc = {
     .bdrv_probe     = vpc_probe,
     .bdrv_open      = vpc_open,
     .bdrv_close     = vpc_close,
+    .bdrv_reopen_prepare = vpc_reopen_prepare,
     .bdrv_create    = vpc_create,
 
     .bdrv_read              = vpc_co_read,
-- 
1.7.6.5

[Qemu-devel] [PATCH 18/19] block: convert bdrv_commit() to use bdrv_reopen()

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

Currently, bdrv_commit() reopens images r/w itself, via risky
_delete() and _open() calls. Use the new safe method for drive reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c |   48 +++++-------------------------------------------
 1 files changed, 5 insertions(+), 43 deletions(-)

diff --git a/block.c b/block.c
index c7c1a3b..84544d2 100644
--- a/block.c
+++ b/block.c
@@ -1501,13 +1501,11 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
 int bdrv_commit(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
-    BlockDriver *backing_drv;
     int64_t sector, total_sectors;
     int n, ro, open_flags;
-    int ret = 0, rw_ret = 0;
+    int ret = 0;
     uint8_t *buf;
     char filename[1024];
-    BlockDriverState *bs_rw, *bs_ro;
 
     if (!drv)
         return -ENOMEDIUM;
@@ -1516,42 +1514,18 @@ int bdrv_commit(BlockDriverState *bs)
         return -ENOTSUP;
     }
 
-    if (bs->backing_hd->keep_read_only) {
-        return -EACCES;
-    }
-
     if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
         return -EBUSY;
     }
 
-    backing_drv = bs->backing_hd->drv;
     ro = bs->backing_hd->read_only;
     strncpy(filename, bs->backing_hd->filename, sizeof(filename));
     open_flags =  bs->backing_hd->open_flags;
 
     if (ro) {
-        /* re-open as RW */
-        bdrv_delete(bs->backing_hd);
-        bs->backing_hd = NULL;
-        bs_rw = bdrv_new("");
-        rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
-            backing_drv);
-        if (rw_ret < 0) {
-            bdrv_delete(bs_rw);
-            /* try to re-open read-only */
-            bs_ro = bdrv_new("");
-            ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
-                backing_drv);
-            if (ret < 0) {
-                bdrv_delete(bs_ro);
-                /* drive not functional anymore */
-                bs->drv = NULL;
-                return ret;
-            }
-            bs->backing_hd = bs_ro;
-            return rw_ret;
+        if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) {
+            return -EACCES;
         }
-        bs->backing_hd = bs_rw;
     }
 
     total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
@@ -1588,20 +1562,8 @@ ro_cleanup:
     g_free(buf);
 
     if (ro) {
-        /* re-open as RO */
-        bdrv_delete(bs->backing_hd);
-        bs->backing_hd = NULL;
-        bs_ro = bdrv_new("");
-        ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
-            backing_drv);
-        if (ret < 0) {
-            bdrv_delete(bs_ro);
-            /* drive not functional anymore */
-            bs->drv = NULL;
-            return ret;
-        }
-        bs->backing_hd = bs_ro;
-        bs->backing_hd->keep_read_only = 0;
+        /* ignoring error return here */
+        bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
     }
 
     return ret;
-- 
1.7.6.5

[Qemu-devel] [PATCH 19/19] block: remove keep_read_only flag from BlockDriverState struct

[Kevin Wolf]

From: Jeff Cody <jcody@redhat.com>

The keep_read_only flag is no longer used, in favor of the bdrv
flag BDRV_O_ALLOW_RDWR.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c     |    2 --
 block_int.h |    1 -
 2 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index 84544d2..751ebdc 100644
--- a/block.c
+++ b/block.c
@@ -812,8 +812,6 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         flags |= BDRV_O_ALLOW_RDWR;
     }
 
-    bs->keep_read_only = !(flags & BDRV_O_ALLOW_RDWR);
-
     /* Open the image */
     ret = bdrv_open_common(bs, filename, flags, drv);
     if (ret < 0) {
diff --git a/block_int.h b/block_int.h
index 22b3d93..ac4245c 100644
--- a/block_int.h
+++ b/block_int.h
@@ -275,7 +275,6 @@ struct BlockDriverState {
     int64_t total_sectors; /* if we are reading a disk image, give its
                               size in sectors */
     int read_only; /* if true, the media is read only */
-    int keep_read_only; /* if true, the media was requested to stay read only */
     int open_flags; /* flags used to open the file, re-used for re-open */
     int encrypted; /* if true, the media is encrypted */
     int valid_key; /* if true, a valid encryption key has been set */
-- 
1.7.6.5

Re: [Qemu-devel] [PULL 00/19] Block patches

[Anthony Liguori]

Kevin Wolf <kwolf@redhat.com> writes:

> The following changes since commit d3e8f95753114a827f9cd8e819b1d5cc8333f76b:
>
>   w32: Add implementation of gmtime_r, localtime_r (2012-09-23 17:09:30 +0000)
>
> are available in the git repository at:
>
>   git://repo.or.cz/qemu/kevin.git for-anthony

Pulled. Thanks.

Regards,

Anthony Liguori

>
> Jeff Cody (18):
>       block: correctly set the keep_read_only flag
>       block: make bdrv_set_enable_write_cache() modify open_flags
>       block: Framework for reopening files safely
>       block: move aio initialization into a helper function
>       block: move open flag parsing in raw block drivers to helper functions
>       block: do not parse BDRV_O_CACHE_WB in block drivers
>       block: use BDRV_O_NOCACHE instead of s->aligned_buf in raw-posix.c
>       block: purge s->aligned_buf and s->aligned_buf_size from raw-posix.c
>       block: raw-posix image file reopen
>       block: raw image file reopen
>       block: qed image file reopen
>       block: qcow2 image file reopen
>       block: qcow image file reopen
>       block: vmdk image file reopen
>       block: vdi image file reopen
>       block: vpc image file reopen
>       block: convert bdrv_commit() to use bdrv_reopen()
>       block: remove keep_read_only flag from BlockDriverState struct
>
> Kevin Shanahan (1):
>       blockdev: preserve readonly and snapshot states across media changes
>
>  block.c           |  299 ++++++++++++++++++++++++++++++++++++++++++++---------
>  block.h           |   18 +++
>  block/iscsi.c     |    4 -
>  block/qcow.c      |   10 ++
>  block/qcow2.c     |   10 ++
>  block/qed.c       |    9 ++
>  block/raw-posix.c |  225 ++++++++++++++++++++++++++++++----------
>  block/raw-win32.c |   40 ++++----
>  block/raw.c       |   10 ++
>  block/rbd.c       |    6 -
>  block/sheepdog.c  |   14 +--
>  block/vdi.c       |    7 ++
>  block/vmdk.c      |   35 ++++++
>  block/vpc.c       |    7 ++
>  block_int.h       |    9 ++-
>  blockdev.c        |    2 +
>  16 files changed, 563 insertions(+), 142 deletions(-)