Re: [Qemu-devel] [PATCH v6 2/8] New -mem-path option - unlink.
On Mon, Jan 13, 2014 at 03:25:13PM +0100, Antonios Motakis wrote:
The unlink option allows the created file to be externally deleted
after QEMU is terminated.
- unlink=on|off - default on, unlink the file after opening it
Signed-off-by: Antonios Motakis a.mota...@virtualopensystems.com
Signed-off-by: Nikolay Nikolaev n.nikol...@virtualopensystems.com
I have doubts about this patch.
In particular we seem to commit to a specific
file naming scheme without ever documenting
its users or adding any tests.
Please document who uses this in the commit log,
document the scheme in docs/ and add a test so we
don't break this without noticing.
---
exec.c | 18 +-
qemu-options.hx | 7 ---
vl.c| 4
3 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/exec.c b/exec.c
index 1c40a0d..30f4019 100644
--- a/exec.c
+++ b/exec.c
@@ -999,7 +999,7 @@ static void *file_ram_alloc(RAMBlock *block,
int flags;
unsigned long hpagesize;
QemuOpts *opts;
-unsigned int mem_prealloc = 0, mem_share = 0;
+unsigned int mem_prealloc = 0, mem_share = 0, mem_unlink = 1;
hpagesize = gethugepagesize(path);
if (!hpagesize) {
@@ -1020,6 +1020,7 @@ static void *file_ram_alloc(RAMBlock *block,
if (opts) {
mem_prealloc = qemu_opt_get_bool(opts, prealloc, 0);
mem_share = qemu_opt_get_bool(opts, share, 0);
+mem_unlink = qemu_opt_get_bool(opts, unlink, 1);
}
/* Make name safe to use with mkstemp by replacing '/' with '_'. */
@@ -1029,18 +1030,25 @@ static void *file_ram_alloc(RAMBlock *block,
*c = '_';
}
-filename = g_strdup_printf(%s/qemu_back_mem.%s.XX, path,
- sanitized_name);
+filename = g_strdup_printf(%s/qemu_back_mem.%s%s, path, sanitized_name,
+ (mem_unlink) ? .XX : );
g_free(sanitized_name);
-fd = mkstemp(filename);
+if (mem_unlink) {
+fd = mkstemp(filename);
+} else {
+fd = open(filename, O_CREAT | O_RDWR | O_EXCL,
+S_IRWXU | S_IRWXG | S_IRWXO);
+}
if (fd 0) {
perror(unable to create guest RAM backing store);
g_free(filename);
return NULL;
}
-unlink(filename);
+if (mem_unlink) {
+unlink(filename);
+}
g_free(filename);
memory = (memory + hpagesize - 1) ~(hpagesize - 1);
diff --git a/qemu-options.hx b/qemu-options.hx
index 60ecc95..a12af97 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -221,14 +221,15 @@ gigabytes respectively.
ETEXI
DEF(mem-path, HAS_ARG, QEMU_OPTION_mempath,
--mem-path [path=]path[,prealloc=on|off][,share=on|off]\n
+-mem-path
[path=]path[,prealloc=on|off][,share=on|off][,unlink=on|off]\n
provide backing storage for guest RAM\n
path= a directory path for the backing store\n
prealloc= preallocate guest memory [default disabled]\n
-share= enable mmap share flag [default disabled]\n,
+share= enable mmap share flag [default disabled]\n
+unlink= enable unlinking the guest RAM files [default
enabled]\n,
QEMU_ARCH_ALL)
STEXI
-@item -mem-path [path=]@var{path}[,prealloc=on|off][,share=on|off]
+@item -mem-path
[path=]@var{path}[,prealloc=on|off][,share=on|off][,unlink=on|off]
@findex -mem-path
Allocate guest RAM from a temporarily created file in @var{path}.
ETEXI
diff --git a/vl.c b/vl.c
index e98abc8..5034bb6 100644
--- a/vl.c
+++ b/vl.c
@@ -546,6 +546,10 @@ static QemuOptsList qemu_mem_path_opts = {
.name = share,
.type = QEMU_OPT_BOOL,
},
+{
+.name = unlink,
+.type = QEMU_OPT_BOOL,
+},
{ /* end of list */ }
},
};
--
1.8.3.2
Re: [Qemu-devel] [PATCH v6 2/8] New -mem-path option - unlink.
On Tue, Jan 14, 2014 at 12:16 PM, Michael S. Tsirkin m...@redhat.com wrote:
On Mon, Jan 13, 2014 at 03:25:13PM +0100, Antonios Motakis wrote:
The unlink option allows the created file to be externally deleted
after QEMU is terminated.
- unlink=on|off - default on, unlink the file after opening it
Signed-off-by: Antonios Motakis a.mota...@virtualopensystems.com
Signed-off-by: Nikolay Nikolaev n.nikol...@virtualopensystems.com
I have doubts about this patch.
In particular we seem to commit to a specific
file naming scheme without ever documenting
its users or adding any tests.
Please document who uses this in the commit log,
document the scheme in docs/ and add a test so we
don't break this without noticing.
We added this feature based on the comments we received on this mailing
list from reviewers. We do not need it from our point of view, so for us it
is straightforward to remove it.
---
exec.c | 18 +-
qemu-options.hx | 7 ---
vl.c| 4
3 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/exec.c b/exec.c
index 1c40a0d..30f4019 100644
--- a/exec.c
+++ b/exec.c
@@ -999,7 +999,7 @@ static void *file_ram_alloc(RAMBlock *block,
int flags;
unsigned long hpagesize;
QemuOpts *opts;
-unsigned int mem_prealloc = 0, mem_share = 0;
+unsigned int mem_prealloc = 0, mem_share = 0, mem_unlink = 1;
hpagesize = gethugepagesize(path);
if (!hpagesize) {
@@ -1020,6 +1020,7 @@ static void *file_ram_alloc(RAMBlock *block,
if (opts) {
mem_prealloc = qemu_opt_get_bool(opts, prealloc, 0);
mem_share = qemu_opt_get_bool(opts, share, 0);
+mem_unlink = qemu_opt_get_bool(opts, unlink, 1);
}
/* Make name safe to use with mkstemp by replacing '/' with '_'. */
@@ -1029,18 +1030,25 @@ static void *file_ram_alloc(RAMBlock *block,
*c = '_';
}
-filename = g_strdup_printf(%s/qemu_back_mem.%s.XX, path,
- sanitized_name);
+filename = g_strdup_printf(%s/qemu_back_mem.%s%s, path,
sanitized_name,
+ (mem_unlink) ? .XX : );
g_free(sanitized_name);
-fd = mkstemp(filename);
+if (mem_unlink) {
+fd = mkstemp(filename);
+} else {
+fd = open(filename, O_CREAT | O_RDWR | O_EXCL,
+S_IRWXU | S_IRWXG | S_IRWXO);
+}
if (fd 0) {
perror(unable to create guest RAM backing store);
g_free(filename);
return NULL;
}
-unlink(filename);
+if (mem_unlink) {
+unlink(filename);
+}
g_free(filename);
memory = (memory + hpagesize - 1) ~(hpagesize - 1);
diff --git a/qemu-options.hx b/qemu-options.hx
index 60ecc95..a12af97 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -221,14 +221,15 @@ gigabytes respectively.
ETEXI
DEF(mem-path, HAS_ARG, QEMU_OPTION_mempath,
--mem-path [path=]path[,prealloc=on|off][,share=on|off]\n
+-mem-path
[path=]path[,prealloc=on|off][,share=on|off][,unlink=on|off]\n
provide backing storage for guest RAM\n
path= a directory path for the backing store\n
prealloc= preallocate guest memory [default
disabled]\n
-share= enable mmap share flag [default
disabled]\n,
+share= enable mmap share flag [default disabled]\n
+unlink= enable unlinking the guest RAM files
[default enabled]\n,
QEMU_ARCH_ALL)
STEXI
-@item -mem-path [path=]@var{path}[,prealloc=on|off][,share=on|off]
+@item -mem-path
[path=]@var{path}[,prealloc=on|off][,share=on|off][,unlink=on|off]
@findex -mem-path
Allocate guest RAM from a temporarily created file in @var{path}.
ETEXI
diff --git a/vl.c b/vl.c
index e98abc8..5034bb6 100644
--- a/vl.c
+++ b/vl.c
@@ -546,6 +546,10 @@ static QemuOptsList qemu_mem_path_opts = {
.name = share,
.type = QEMU_OPT_BOOL,
},
+{
+.name = unlink,
+.type = QEMU_OPT_BOOL,
+},
{ /* end of list */ }
},
};
--
1.8.3.2
[Qemu-devel] [PATCH v6 2/8] New -mem-path option - unlink.
The unlink option allows the created file to be externally deleted
after QEMU is terminated.
- unlink=on|off - default on, unlink the file after opening it
Signed-off-by: Antonios Motakis a.mota...@virtualopensystems.com
Signed-off-by: Nikolay Nikolaev n.nikol...@virtualopensystems.com
---
exec.c | 18 +-
qemu-options.hx | 7 ---
vl.c| 4
3 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/exec.c b/exec.c
index 1c40a0d..30f4019 100644
--- a/exec.c
+++ b/exec.c
@@ -999,7 +999,7 @@ static void *file_ram_alloc(RAMBlock *block,
int flags;
unsigned long hpagesize;
QemuOpts *opts;
-unsigned int mem_prealloc = 0, mem_share = 0;
+unsigned int mem_prealloc = 0, mem_share = 0, mem_unlink = 1;
hpagesize = gethugepagesize(path);
if (!hpagesize) {
@@ -1020,6 +1020,7 @@ static void *file_ram_alloc(RAMBlock *block,
if (opts) {
mem_prealloc = qemu_opt_get_bool(opts, prealloc, 0);
mem_share = qemu_opt_get_bool(opts, share, 0);
+mem_unlink = qemu_opt_get_bool(opts, unlink, 1);
}
/* Make name safe to use with mkstemp by replacing '/' with '_'. */
@@ -1029,18 +1030,25 @@ static void *file_ram_alloc(RAMBlock *block,
*c = '_';
}
-filename = g_strdup_printf(%s/qemu_back_mem.%s.XX, path,
- sanitized_name);
+filename = g_strdup_printf(%s/qemu_back_mem.%s%s, path, sanitized_name,
+ (mem_unlink) ? .XX : );
g_free(sanitized_name);
-fd = mkstemp(filename);
+if (mem_unlink) {
+fd = mkstemp(filename);
+} else {
+fd = open(filename, O_CREAT | O_RDWR | O_EXCL,
+S_IRWXU | S_IRWXG | S_IRWXO);
+}
if (fd 0) {
perror(unable to create guest RAM backing store);
g_free(filename);
return NULL;
}
-unlink(filename);
+if (mem_unlink) {
+unlink(filename);
+}
g_free(filename);
memory = (memory + hpagesize - 1) ~(hpagesize - 1);
diff --git a/qemu-options.hx b/qemu-options.hx
index 60ecc95..a12af97 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -221,14 +221,15 @@ gigabytes respectively.
ETEXI
DEF(mem-path, HAS_ARG, QEMU_OPTION_mempath,
--mem-path [path=]path[,prealloc=on|off][,share=on|off]\n
+-mem-path [path=]path[,prealloc=on|off][,share=on|off][,unlink=on|off]\n
provide backing storage for guest RAM\n
path= a directory path for the backing store\n
prealloc= preallocate guest memory [default disabled]\n
-share= enable mmap share flag [default disabled]\n,
+share= enable mmap share flag [default disabled]\n
+unlink= enable unlinking the guest RAM files [default
enabled]\n,
QEMU_ARCH_ALL)
STEXI
-@item -mem-path [path=]@var{path}[,prealloc=on|off][,share=on|off]
+@item -mem-path
[path=]@var{path}[,prealloc=on|off][,share=on|off][,unlink=on|off]
@findex -mem-path
Allocate guest RAM from a temporarily created file in @var{path}.
ETEXI
diff --git a/vl.c b/vl.c
index e98abc8..5034bb6 100644
--- a/vl.c
+++ b/vl.c
@@ -546,6 +546,10 @@ static QemuOptsList qemu_mem_path_opts = {
.name = share,
.type = QEMU_OPT_BOOL,
},
+{
+.name = unlink,
+.type = QEMU_OPT_BOOL,
+},
{ /* end of list */ }
},
};
--
1.8.3.2
