Re: [PATCH v2] btrfs-progs: btrfs: implement 'start-sync' and 'wait-sync' commands
On Tuesday, 02 November, 2010, you (Sage Weil) wrote:
On Tue, 2 Nov 2010, Goffredo Baroncelli wrote:
Like the command btrfs subvol snapshot, I think that it is better to add
a
modifier instead of a new command.
btrfs filesystem sync [--async]
Sorry if I noticed this too late. But I don't see a valid reason to add
another command. From a UI point of view the meaning of the command is the
same, change only slight the behavior.
Even tough I have to admint that sync --async sound strange. May be
flush is
better ?
+ { do_wait_sync, 2,
+ filesystem wait-sync, path transid\n
+ Wait for the transaction transid on the filesystem at
path to commit.
+ },
If I understood correctly this command may be used to wait the execution
of
several commands: snapshot, subvolume removal, sync...
I can suggest a more general name like:
# btrfs filesystem wait-transaction path transid.
(which may be shortened as btrfs filesystem wait ...).
How about start-transaction and wait-transaction? Or start-commit and
wait-commit? ('transaction' is a heavily overloaded term.) IMO both
would be less weird than sync --async.
IMHO, commit is when a transaction start; the transaction is what pushes the
data on the disk. So I prefer wait/start-transaction.
But I prefer that an english people says the last word.
BTW which guarantees provide the commands start-wait-transaction ? What happen
if a powerloss happens before wait-* but after a start*.
Goffredo
Another suggestion: instead of checking if the transid is 0, leave the
transid optional. If transid is omitted, then the function waits all
the
running transaction.
Definitely.
Finally I suggest to put a little note about the command behvior when a
transaction is started after the command execution: is there a risk of DOS
?
Okay. There's no DOS risk (at least no more so than with while true ; do
sync ; done). It'll return immediately if transid has committed. If
transid is 0, it'll find the most recent committing or committed transid
and wait for that. If nothing is currently committing, it'll return
immediately.
sage
Anyway great work.
Goffredo
{ do_resize, 2,
filesystem resize, [+/-]newsize[gkm]|max filesystem\n
Resize the file system. If 'max' is passed, the filesystem\n
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 8031c58..736437d 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -526,6 +526,55 @@ int do_fssync(int argc, char **argv)
return 0;
}
+int do_start_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid;
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(StartSync '%s'\n, path);
+ res = ioctl(fd, BTRFS_IOC_START_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to fs-syncing '%s'\n, path);
+ return 16;
+ } else {
+ printf(transid %llu\n, (unsigned long long)transid);
+ }
+
+ return 0;
+}
+
+int do_wait_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid = atoll(argv[2]);
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(WaitSync '%s' transid %llu\n, path, (unsigned long
long)transid);
+ res = ioctl(fd, BTRFS_IOC_WAIT_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to wait-sync on '%s' transid
%llu: %s\n, path,
+ (unsigned long long)transid, strerror(errno));
+ return 16;
+ }
+
+ return 0;
+}
+
int do_scan(int argc, char **argv)
{
int i, fd;
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 7bde191..84c489f 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -19,6 +19,8 @@ int do_clone(int nargs, char **argv);
int do_delete_subvolume(int nargs, char **argv);
int do_create_subvol(int nargs, char **argv);
int do_fssync(int nargs, char **argv);
+int do_start_sync(int nargs, char **argv);
+int do_wait_sync(int nargs, char **argv);
int do_defrag(int argc, char **argv);
int do_show_filesystem(int nargs, char **argv);
int do_add_volume(int nargs, char **args);
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 26ef982..e87b5fe 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -19,6 +19,10 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBfilesystem sync\fP\fI path \fP
.PP
+\fBbtrfs\fP \fBfilesystem start-sync\fP\fI path \fP
+.PP
+\fBbtrfs\fP \fBfilesystem wait-sync\fP\fI path transid\fP
+.PP
\fBbtrfs\fP \fBfilesystem resize\fP\fI [+/\-]size[gkm]|max
Re: [PATCH v2] btrfs-progs: btrfs: implement 'start-sync' and 'wait-sync' commands
On Tue, Nov 02, 2010 at 07:58:27PM +0100, Goffredo Baroncelli wrote:
On Monday, 01 November, 2010, Sage Weil wrote:
The 'start-sync' command initiates a sync, but does not wait for it to
complete. A transaction is printed that can be fed to 'wait-sync', which
will wait for it to commit.
'wait-sync' can also be used in combination with 'async-snapshot' to wait
for an async snapshot creation to commit.
Updates the man page too.
Signed-off-by: Sage Weil s...@newdream.net
---
btrfs.c|9 +
btrfs_cmds.c | 49 +
btrfs_cmds.h |2 ++
man/btrfs.8.in | 14 ++
4 files changed, 74 insertions(+), 0 deletions(-)
diff --git a/btrfs.c b/btrfs.c
index 46314cf..c871f4a 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -77,6 +77,15 @@ static struct Command commands[] = {
filesystem sync, path\n
Force a sync on the filesystem path.
},
+ { do_start_sync, 1,
+ filesystem start-sync, path\n
+ Start a sync on the filesystem path, and print the
resulting\n
+ transaction id.
+ },
Like the command btrfs subvol snapshot, I think that it is better to add a
modifier instead of a new command.
btrfs filesystem sync [--async]
Sorry if I noticed this too late. But I don't see a valid reason to add
another command. From a UI point of view the meaning of the command is the
same, change only slight the behavior.
Even tough I have to admint that sync --async sound strange. May be flush
is
better ?
How about btrfs filesystem sync --background?
Hugo.
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PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
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Re: [PATCH v2] btrfs-progs: btrfs: implement 'start-sync' and 'wait-sync' commands
On Monday, 01 November, 2010, Sage Weil wrote:
The 'start-sync' command initiates a sync, but does not wait for it to
complete. A transaction is printed that can be fed to 'wait-sync', which
will wait for it to commit.
'wait-sync' can also be used in combination with 'async-snapshot' to wait
for an async snapshot creation to commit.
Updates the man page too.
Signed-off-by: Sage Weil s...@newdream.net
---
btrfs.c|9 +
btrfs_cmds.c | 49 +
btrfs_cmds.h |2 ++
man/btrfs.8.in | 14 ++
4 files changed, 74 insertions(+), 0 deletions(-)
diff --git a/btrfs.c b/btrfs.c
index 46314cf..c871f4a 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -77,6 +77,15 @@ static struct Command commands[] = {
filesystem sync, path\n
Force a sync on the filesystem path.
},
+ { do_start_sync, 1,
+ filesystem start-sync, path\n
+ Start a sync on the filesystem path, and print the
resulting\n
+ transaction id.
+ },
Like the command btrfs subvol snapshot, I think that it is better to add a
modifier instead of a new command.
btrfs filesystem sync [--async]
Sorry if I noticed this too late. But I don't see a valid reason to add
another command. From a UI point of view the meaning of the command is the
same, change only slight the behavior.
Even tough I have to admint that sync --async sound strange. May be flush is
better ?
+ { do_wait_sync, 2,
+ filesystem wait-sync, path transid\n
+ Wait for the transaction transid on the filesystem at
path to commit.
+ },
If I understood correctly this command may be used to wait the execution of
several commands: snapshot, subvolume removal, sync...
I can suggest a more general name like:
# btrfs filesystem wait-transaction path transid.
(which may be shortened as btrfs filesystem wait ...).
Another suggestion: instead of checking if the transid is 0, leave the
transid optional. If transid is omitted, then the function waits all the
running transaction.
Finally I suggest to put a little note about the command behvior when a
transaction is started after the command execution: is there a risk of DOS ?
Anyway great work.
Goffredo
{ do_resize, 2,
filesystem resize, [+/-]newsize[gkm]|max filesystem\n
Resize the file system. If 'max' is passed, the filesystem\n
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 8031c58..736437d 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -526,6 +526,55 @@ int do_fssync(int argc, char **argv)
return 0;
}
+int do_start_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid;
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(StartSync '%s'\n, path);
+ res = ioctl(fd, BTRFS_IOC_START_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to fs-syncing '%s'\n, path);
+ return 16;
+ } else {
+ printf(transid %llu\n, (unsigned long long)transid);
+ }
+
+ return 0;
+}
+
+int do_wait_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid = atoll(argv[2]);
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(WaitSync '%s' transid %llu\n, path, (unsigned long
long)transid);
+ res = ioctl(fd, BTRFS_IOC_WAIT_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to wait-sync on '%s' transid
%llu: %s\n, path,
+ (unsigned long long)transid, strerror(errno));
+ return 16;
+ }
+
+ return 0;
+}
+
int do_scan(int argc, char **argv)
{
int i, fd;
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 7bde191..84c489f 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -19,6 +19,8 @@ int do_clone(int nargs, char **argv);
int do_delete_subvolume(int nargs, char **argv);
int do_create_subvol(int nargs, char **argv);
int do_fssync(int nargs, char **argv);
+int do_start_sync(int nargs, char **argv);
+int do_wait_sync(int nargs, char **argv);
int do_defrag(int argc, char **argv);
int do_show_filesystem(int nargs, char **argv);
int do_add_volume(int nargs, char **args);
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 26ef982..e87b5fe 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -19,6 +19,10 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBfilesystem sync\fP\fI path \fP
.PP
+\fBbtrfs\fP \fBfilesystem start-sync\fP\fI path \fP
+.PP
+\fBbtrfs\fP \fBfilesystem wait-sync\fP\fI path transid\fP
+.PP
\fBbtrfs\fP \fBfilesystem
Re: [PATCH v2] btrfs-progs: btrfs: implement 'start-sync' and 'wait-sync' commands
On Tue, 2 Nov 2010, Goffredo Baroncelli wrote:
Like the command btrfs subvol snapshot, I think that it is better to add a
modifier instead of a new command.
btrfs filesystem sync [--async]
Sorry if I noticed this too late. But I don't see a valid reason to add
another command. From a UI point of view the meaning of the command is the
same, change only slight the behavior.
Even tough I have to admint that sync --async sound strange. May be flush
is
better ?
+ { do_wait_sync, 2,
+ filesystem wait-sync, path transid\n
+ Wait for the transaction transid on the filesystem at
path to commit.
+ },
If I understood correctly this command may be used to wait the execution of
several commands: snapshot, subvolume removal, sync...
I can suggest a more general name like:
# btrfs filesystem wait-transaction path transid.
(which may be shortened as btrfs filesystem wait ...).
How about start-transaction and wait-transaction? Or start-commit and
wait-commit? ('transaction' is a heavily overloaded term.) IMO both
would be less weird than sync --async.
Another suggestion: instead of checking if the transid is 0, leave the
transid optional. If transid is omitted, then the function waits all the
running transaction.
Definitely.
Finally I suggest to put a little note about the command behvior when a
transaction is started after the command execution: is there a risk of DOS ?
Okay. There's no DOS risk (at least no more so than with while true ; do
sync ; done). It'll return immediately if transid has committed. If
transid is 0, it'll find the most recent committing or committed transid
and wait for that. If nothing is currently committing, it'll return
immediately.
sage
Anyway great work.
Goffredo
{ do_resize, 2,
filesystem resize, [+/-]newsize[gkm]|max filesystem\n
Resize the file system. If 'max' is passed, the filesystem\n
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 8031c58..736437d 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -526,6 +526,55 @@ int do_fssync(int argc, char **argv)
return 0;
}
+int do_start_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid;
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(StartSync '%s'\n, path);
+ res = ioctl(fd, BTRFS_IOC_START_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to fs-syncing '%s'\n, path);
+ return 16;
+ } else {
+ printf(transid %llu\n, (unsigned long long)transid);
+ }
+
+ return 0;
+}
+
+int do_wait_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid = atoll(argv[2]);
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(WaitSync '%s' transid %llu\n, path, (unsigned long
long)transid);
+ res = ioctl(fd, BTRFS_IOC_WAIT_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to wait-sync on '%s' transid
%llu: %s\n, path,
+ (unsigned long long)transid, strerror(errno));
+ return 16;
+ }
+
+ return 0;
+}
+
int do_scan(int argc, char **argv)
{
int i, fd;
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 7bde191..84c489f 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -19,6 +19,8 @@ int do_clone(int nargs, char **argv);
int do_delete_subvolume(int nargs, char **argv);
int do_create_subvol(int nargs, char **argv);
int do_fssync(int nargs, char **argv);
+int do_start_sync(int nargs, char **argv);
+int do_wait_sync(int nargs, char **argv);
int do_defrag(int argc, char **argv);
int do_show_filesystem(int nargs, char **argv);
int do_add_volume(int nargs, char **args);
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 26ef982..e87b5fe 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -19,6 +19,10 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBfilesystem sync\fP\fI path \fP
.PP
+\fBbtrfs\fP \fBfilesystem start-sync\fP\fI path \fP
+.PP
+\fBbtrfs\fP \fBfilesystem wait-sync\fP\fI path transid\fP
+.PP
\fBbtrfs\fP \fBfilesystem resize\fP\fI [+/\-]size[gkm]|max
filesystem\fP
.PP
\fBbtrfs\fP \fBdevice scan\fP\fI [device [device..]]\fP
@@ -115,6 +119,16 @@ all the block devices.
Force a sync for the filesystem identified by \fIpath\fR.
.TP
+\fBfilesystem start-sync\fR\fI path \fR
+Start a sync operation for the filesystem identified by \fIpath\fR. A
transaction id
+is printed that can be waited on using the \fBfilesystem wait-sync\fR
command.
+.TP
+
+\fBfilesystem
[PATCH v2] btrfs-progs: btrfs: implement 'start-sync' and 'wait-sync' commands
The 'start-sync' command initiates a sync, but does not wait for it to
complete. A transaction is printed that can be fed to 'wait-sync', which
will wait for it to commit.
'wait-sync' can also be used in combination with 'async-snapshot' to wait
for an async snapshot creation to commit.
Updates the man page too.
Signed-off-by: Sage Weil s...@newdream.net
---
btrfs.c|9 +
btrfs_cmds.c | 49 +
btrfs_cmds.h |2 ++
man/btrfs.8.in | 14 ++
4 files changed, 74 insertions(+), 0 deletions(-)
diff --git a/btrfs.c b/btrfs.c
index 46314cf..c871f4a 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -77,6 +77,15 @@ static struct Command commands[] = {
filesystem sync, path\n
Force a sync on the filesystem path.
},
+ { do_start_sync, 1,
+ filesystem start-sync, path\n
+ Start a sync on the filesystem path, and print the
resulting\n
+ transaction id.
+ },
+ { do_wait_sync, 2,
+ filesystem wait-sync, path transid\n
+ Wait for the transaction transid on the filesystem at path
to commit.
+ },
{ do_resize, 2,
filesystem resize, [+/-]newsize[gkm]|max filesystem\n
Resize the file system. If 'max' is passed, the filesystem\n
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 8031c58..736437d 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -526,6 +526,55 @@ int do_fssync(int argc, char **argv)
return 0;
}
+int do_start_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid;
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(StartSync '%s'\n, path);
+ res = ioctl(fd, BTRFS_IOC_START_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to fs-syncing '%s'\n, path);
+ return 16;
+ } else {
+ printf(transid %llu\n, (unsigned long long)transid);
+ }
+
+ return 0;
+}
+
+int do_wait_sync(int argc, char **argv)
+{
+ int fd, res;
+ char*path = argv[1];
+ __u64 transid = atoll(argv[2]);
+
+ fd = open_file_or_dir(path);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access to '%s'\n, path);
+ return 12;
+ }
+
+ printf(WaitSync '%s' transid %llu\n, path, (unsigned long
long)transid);
+ res = ioctl(fd, BTRFS_IOC_WAIT_SYNC, transid);
+ close(fd);
+ if( res 0 ){
+ fprintf(stderr, ERROR: unable to wait-sync on '%s' transid
%llu: %s\n, path,
+ (unsigned long long)transid, strerror(errno));
+ return 16;
+ }
+
+ return 0;
+}
+
int do_scan(int argc, char **argv)
{
int i, fd;
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 7bde191..84c489f 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -19,6 +19,8 @@ int do_clone(int nargs, char **argv);
int do_delete_subvolume(int nargs, char **argv);
int do_create_subvol(int nargs, char **argv);
int do_fssync(int nargs, char **argv);
+int do_start_sync(int nargs, char **argv);
+int do_wait_sync(int nargs, char **argv);
int do_defrag(int argc, char **argv);
int do_show_filesystem(int nargs, char **argv);
int do_add_volume(int nargs, char **args);
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 26ef982..e87b5fe 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -19,6 +19,10 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBfilesystem sync\fP\fI path \fP
.PP
+\fBbtrfs\fP \fBfilesystem start-sync\fP\fI path \fP
+.PP
+\fBbtrfs\fP \fBfilesystem wait-sync\fP\fI path transid\fP
+.PP
\fBbtrfs\fP \fBfilesystem resize\fP\fI [+/\-]size[gkm]|max filesystem\fP
.PP
\fBbtrfs\fP \fBdevice scan\fP\fI [device [device..]]\fP
@@ -115,6 +119,16 @@ all the block devices.
Force a sync for the filesystem identified by \fIpath\fR.
.TP
+\fBfilesystem start-sync\fR\fI path \fR
+Start a sync operation for the filesystem identified by \fIpath\fR. A
transaction id
+is printed that can be waited on using the \fBfilesystem wait-sync\fR command.
+.TP
+
+\fBfilesystem wait-sync\fR\fI path transid\fR
+Wait for a the transaction \fItransid\fR to commit to disk. If
\fItransid\fR is zero,
+wait for any currently committing transaction to commit.
+.TP
+
.\
.\ Some wording are extracted by the resize2fs man page
.\
--
1.7.0
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