From 47a21881507f1bba1cf2fbabb0f8efce57ee7fb9 Mon Sep 17 00:00:00 2001

From: Max Reitz <mreitz@redhat.com>

Date: Wed, 3 Apr 2019 17:13:11 +0100

Subject: [PATCH 04/11] file-posix: Drop s->lock_fd

RH-Author: Max Reitz <mreitz@redhat.com>

Message-id: <20190403171315.20841-5-mreitz@redhat.com>

Patchwork-id: 85403

O-Subject: [RHEL-8.1 qemu-kvm PATCH 4/8] file-posix: Drop s->lock_fd

Bugzilla: 1694148

RH-Acked-by: John Snow <jsnow@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>

From: Fam Zheng <famz@redhat.com>

The lock_fd field is not strictly necessary because transferring locked

bytes from old fd to the new one shouldn't fail anyway. This spares the

user one fd per image.

Signed-off-by: Fam Zheng <famz@redhat.com>

Reviewed-by: Max Reitz <mreitz@redhat.com>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit f2e3af29b70624659a50903bd075e1663b64c9da)

Signed-off-by: Max Reitz <mreitz@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 block/file-posix.c | 37 +++++++++++++------------------------

 1 file changed, 13 insertions(+), 24 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c

index 2a05193..97e7ff2 100644

--- a/block/file-posix.c

+++ b/block/file-posix.c

@@ -142,7 +142,6 @@ do { \

 typedef struct BDRVRawState {

     int fd;

-    int lock_fd;

     bool use_lock;

     int type;

     int open_flags;

@@ -153,7 +152,7 @@ typedef struct BDRVRawState {

     uint64_t shared_perm;

     /* The perms bits whose corresponding bytes are already locked in

-     * s->lock_fd. */

+     * s->fd. */

     uint64_t locked_perm;

     uint64_t locked_shared_perm;

@@ -545,18 +544,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,

     }

     s->fd = fd;

-    s->lock_fd = -1;

-    if (s->use_lock) {

-        fd = qemu_open(filename, s->open_flags);

-        if (fd < 0) {

-            ret = -errno;

-            error_setg_errno(errp, errno, "Could not open '%s' for locking",

-                             filename);

-            qemu_close(s->fd);

-            goto fail;

-        }

-        s->lock_fd = fd;

-    }

     s->perm = 0;

     s->shared_perm = BLK_PERM_ALL;

@@ -811,15 +798,13 @@ static int raw_handle_perm_lock(BlockDriverState *bs,

         return 0;

     }

-    assert(s->lock_fd > 0);

-

     switch (op) {

     case RAW_PL_PREPARE:

-        ret = raw_apply_lock_bytes(s, s->lock_fd, s->perm | new_perm,

+        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->lock_fd, new_perm, new_shared, errp);

+            ret = raw_check_lock_bytes(s->fd, new_perm, new_shared, errp);

             if (!ret) {

                 return 0;

             }

@@ -830,7 +815,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs,

         op = RAW_PL_ABORT;

         /* fall through to unlock bytes. */

     case RAW_PL_ABORT:

-        raw_apply_lock_bytes(s, s->lock_fd, s->perm, ~s->shared_perm,

+        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

@@ -840,7 +825,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs,

         }

         break;

     case RAW_PL_COMMIT:

-        raw_apply_lock_bytes(s, s->lock_fd, new_perm, ~new_shared,

+        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

@@ -938,9 +923,17 @@ static void raw_reopen_commit(BDRVReopenState *state)

 {

     BDRVRawReopenState *rs = state->opaque;

     BDRVRawState *s = state->bs->opaque;

+    Error *local_err = NULL;

     s->open_flags = rs->open_flags;

+    /* Copy locks to the new fd before closing the old one. */

+    raw_apply_lock_bytes(NULL, rs->fd, s->locked_perm,

+                         ~s->locked_shared_perm, false, &local_err);

+    if (local_err) {

+        /* shouldn't fail in a sane host, but report it just in case. */

+        error_report_err(local_err);

+    }

     qemu_close(s->fd);

     s->fd = rs->fd;

@@ -1903,10 +1896,6 @@ static void raw_close(BlockDriverState *bs)

         qemu_close(s->fd);

         s->fd = -1;

     }

-    if (s->lock_fd >= 0) {

-        qemu_close(s->lock_fd);

-        s->lock_fd = -1;

-    }

 }

 /**

-- 

1.8.3.1