[PATCH v2 1/2] block: report errno when flock fcntl fails

[David Edmondson <david.edmondson@oracle.com>]

When a call to fcntl(2) for the purpose of manipulating file locks
fails, report the error returned by fcntl.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
---
 block/file-posix.c         | 20 +++++-----
 tests/qemu-iotests/153.out | 76 +++++++++++++++++++-------------------
 tests/qemu-iotests/182.out |  2 +-
 3 files changed, 49 insertions(+), 49 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 9804681d5c..f866fc9742 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -836,7 +836,7 @@ static int raw_apply_lock_bytes(BDRVRawState *s, int fd,
         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);
+                error_setg_errno(errp, -ret, "Failed to lock byte %d", off);
                 return ret;
             } else if (s) {
                 s->locked_perm |= bit;
@@ -844,7 +844,7 @@ static int raw_apply_lock_bytes(BDRVRawState *s, int fd,
         } 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);
+                error_setg_errno(errp, -ret, "Failed to unlock byte %d", off);
                 return ret;
             } else if (s) {
                 s->locked_perm &= ~bit;
@@ -857,7 +857,7 @@ static int raw_apply_lock_bytes(BDRVRawState *s, int fd,
         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);
+                error_setg_errno(errp, -ret, "Failed to lock byte %d", off);
                 return ret;
             } else if (s) {
                 s->locked_shared_perm |= bit;
@@ -866,7 +866,7 @@ static int raw_apply_lock_bytes(BDRVRawState *s, int fd,
                    !(shared_perm_lock_bits & bit)) {
             ret = qemu_unlock_fd(fd, off, 1);
             if (ret) {
-                error_setg(errp, "Failed to unlock byte %d", off);
+                error_setg_errno(errp, -ret, "Failed to unlock byte %d", off);
                 return ret;
             } else if (s) {
                 s->locked_shared_perm &= ~bit;
@@ -890,9 +890,9 @@ static int raw_check_lock_bytes(int fd, uint64_t perm, uint64_t shared_perm,
             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);
+                error_setg_errno(errp, -ret,
+                                 "Failed to get \"%s\" lock",
+                                 perm_name);
                 g_free(perm_name);
                 return ret;
             }
@@ -905,9 +905,9 @@ static int raw_check_lock_bytes(int fd, uint64_t perm, uint64_t shared_perm,
             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);
+                error_setg_errno(errp, -ret,
+                                 "Failed to get shared \"%s\" lock",
+                                 perm_name);
                 g_free(perm_name);
                 return ret;
             }
diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
index fcaa71aeee..c1f8494a63 100644
--- a/tests/qemu-iotests/153.out
+++ b/tests/qemu-iotests/153.out
@@ -11,11 +11,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/t
 == Launching QEMU, opts: '' ==
 
 == Launching another QEMU, opts: '' ==
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: Failed to get "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Launching another QEMU, opts: 'read-only=on' ==
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,read-only=on: Failed to get shared "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,read-only=on: Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Launching another QEMU, opts: 'read-only=on,force-share=on' ==
@@ -23,77 +23,77 @@ Is another process using the image [TEST_DIR/t.qcow2]?
 == Running utility commands  ==
 
 _qemu_io_wrapper -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r  TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
 _qemu_img_wrapper info TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper check TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper compare TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper map TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper amend -o size=32M TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper commit TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper resize TEST_DIR/t.qcow2 32M
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper rebase TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base -F qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper convert TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.convert
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper dd if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 count=1
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper bench -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper bench -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper create -f qcow2 TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base -F qcow2
-qemu-img: TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-img: TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 file format: IMGFMT
 backing file format: IMGFMT
@@ -132,7 +132,7 @@ qemu-img: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper rebase -U TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base -F qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l -U TEST_DIR/t.qcow2
@@ -158,7 +158,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/t
 == Launching QEMU, opts: 'read-only=on' ==
 
 == Launching another QEMU, opts: '' ==
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: Failed to get "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Launching another QEMU, opts: 'read-only=on' ==
@@ -168,13 +168,13 @@ Is another process using the image [TEST_DIR/t.qcow2]?
 == Running utility commands  ==
 
 _qemu_io_wrapper -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
@@ -189,19 +189,19 @@ _qemu_img_wrapper compare TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 _qemu_img_wrapper map TEST_DIR/t.qcow2
 
 _qemu_img_wrapper amend -o size=32M TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper commit TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper resize TEST_DIR/t.qcow2 32M
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper rebase TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base -F qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l TEST_DIR/t.qcow2
@@ -213,11 +213,11 @@ _qemu_img_wrapper dd if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 coun
 _qemu_img_wrapper bench -c 1 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper bench -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper create -f qcow2 TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base -F qcow2
-qemu-img: TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-img: TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 file format: IMGFMT
 backing file format: IMGFMT
@@ -256,7 +256,7 @@ qemu-img: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper rebase -U TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base -F qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l -U TEST_DIR/t.qcow2
@@ -377,17 +377,17 @@ qemu-img: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used wit
 Round done
 
 == Two devices with the same image (read-only=off - read-only=off) ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Two devices with the same image (read-only=off - read-only=on) ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=on: Failed to get shared "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=on: Failed to get shared "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Two devices with the same image (read-only=off - read-only=on,force-share=on) ==
 
 == Two devices with the same image (read-only=on - read-only=off) ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Two devices with the same image (read-only=on - read-only=on) ==
@@ -408,13 +408,13 @@ Formatting 'TEST_DIR/t.IMGFMT.c', fmt=IMGFMT size=33554432 backing_file=TEST_DIR
 == Two devices sharing the same file in backing chain ==
 
 == Backing image also as an active device ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Backing image also as an active device (ro) ==
 
 == Symbolic link ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Active commit to intermediate layer should work when base in use ==
@@ -429,7 +429,7 @@ Adding drive
 {"return": "OKrn"}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 Creating overlay with qemu-img when the guest is running should be allowed
 
@@ -450,7 +450,7 @@ _qemu_img_wrapper info TEST_DIR/t.qcow2
 {"return": ""}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 Closing the other
 { 'execute': 'human-monitor-command', 'arguments': { 'command-line': 'drive_del d1' } }
diff --git a/tests/qemu-iotests/182.out b/tests/qemu-iotests/182.out
index ce23340670..63b7ecb325 100644
--- a/tests/qemu-iotests/182.out
+++ b/tests/qemu-iotests/182.out
@@ -3,7 +3,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432
 Starting QEMU
 
 Starting a second QEMU using the same image should fail
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,id=drive0,file.locking=on: Failed to get "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,id=drive0,file.locking=on: Failed to get "write" lock: Resource temporarily unavailable
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 === Testing reopen ===
-- 
2.29.2