Re: [Libguestfs] [PATCH] New API: btrfs_replace_start

Hi, On Wednesday 10 June 2015 17:54:18 Pino Tsao wrote: > Signed-off-by: Pino Tsao <caoj.fnst(a)cn.fujitsu.com&gt; > --- > daemon/btrfs.c | 40 +++++++++++++++++++++++++++++++++++++++ > generator/actions.ml | 19 +++++++++++++++++++ > tests/btrfs/test-btrfs-devices.sh | 8 ++++++++ > 3 files changed, 67 insertions(+) > > diff --git a/daemon/btrfs.c b/daemon/btrfs.c > index 39392f7..acc300d 100644 > --- a/daemon/btrfs.c > +++ b/daemon/btrfs.c > @@ -2083,3 +2083,43 @@ do_btrfs_image (char *const *sources, const char *image, > > return 0; > } > + > +int > +do_btrfs_replace_start (const char *srcdev, const char *targetdev, > + const char* mntpoint, int force) > +{ > + const size_t MAX_ARGS = 64; > + const char *argv[MAX_ARGS]; > + size_t i = 0; > + CLEANUP_FREE char *err = NULL; > + CLEANUP_FREE char *path_buf = NULL; > + int r; > + > + path_buf = sysroot_path (mntpoint); > + if (path_buf == NULL) { > + reply_with_perror ("malloc"); > + return -1; > + } > + > + ADD_ARG (argv, i, str_btrfs); > + ADD_ARG (argv, i, "replace"); > + ADD_ARG (argv, i, "start"); > + ADD_ARG (argv, i, srcdev); > + ADD_ARG (argv, i, targetdev); > + ADD_ARG (argv, i, path_buf); > + ADD_ARG (argv, i, "-B"); I get that -B turns the operation from a background one to synchronous, so why does this API have a _start suffix?

> + > + if ((optargs_bitmask & GUESTFS_BTRFS_REPLACE_START_FORCE_BITMASK) && force) > + ADD_ARG (argv, i, "-f"); Shouldn't -f be always passed, instead of having to choose it?

> + > + ADD_ARG (argv, i, NULL); > + > + r = commandv (NULL, &err, argv); > + if (r == -1) { > + reply_with_error ("%s: %s", mntpoint, err); > + return -1; > + } > + > + return 0; > +} > + > diff --git a/generator/actions.ml b/generator/actions.ml > index 1a89869..4443600 100644 > --- a/generator/actions.ml > +++ b/generator/actions.ml > @@ -12579,6 +12579,25 @@ numbered C<partnum> on device C<device>. > > It returns C<primary>, C<logical>, or C<extended>." }; > > + { defaults with > + name = "btrfs_replace_start"; added = (1, 29, 46); > + style = RErr, [Device "srcdev"; Device "targetdev"; Pathname "mntpoint"], [OBool "force"]; > + proc_nr = Some 455; > + optional = Some "btrfs"; camel_name = "BTRFSReplaceStart"; > + test_excuse = "It is better to have 3+ test disk to do the test, so put the test in 'tests/btrfs' directory"; > + shortdesc = "replace a btrfs managed device with another device"; > + longdesc = "\ > +Replace device of a btrfs filesystem. On a live filesystem, duplicate the data > +to the target device which is currently stored on the source device. > +After completion of the operation, the source device is wiped out and > +removed from the filesystem. > + > +The <targetdev> needs to be same size or larger than the <srcdev>. Devices > +which are currently mounted are never allowed to be used as the <targetdev> > + > +Option 'force=true' means using and overwriting <targetdev> even if > +it looks like containing a valid btrfs filesystem." }; > + > ] > > (* Non-API meta-commands available only in guestfish. > diff --git a/tests/btrfs/test-btrfs-devices.sh b/tests/btrfs/test-btrfs-devices.sh > index 3935c60..463b0a8 100755 > --- a/tests/btrfs/test-btrfs-devices.sh > +++ b/tests/btrfs/test-btrfs-devices.sh > @@ -66,6 +66,8 @@ btrfs-device-add "/dev/sdc1 /dev/sdd1" / > btrfs-device-delete "/dev/sdb1" / > btrfs-device-add "/dev/sdb1" / > btrfs-device-delete "/dev/sdc1 /dev/sdd1" / > +btrfs-replace-start "/dev/sda1" "/dev/sdd1" / force:true > +btrfs-replace-start "/dev/sdd1" "/dev/sda1" / force:true > > mkdir /data2 > tar-in $srcdir/../data/filesanddirs-10M.tar.xz /data2 compress:xz > @@ -74,6 +76,8 @@ btrfs-device-add "/dev/sdc1 /dev/sdd1" / > btrfs-device-delete "/dev/sdb1" / > btrfs-device-add "/dev/sdb1" / > btrfs-device-delete "/dev/sdc1 /dev/sdd1" / > +btrfs-replace-start "/dev/sda1" "/dev/sdd1" / force:true > +btrfs-replace-start "/dev/sdd1" "/dev/sda1" / force:true > > mkdir /data3 > tar-in $srcdir/../data/filesanddirs-10M.tar.xz /data3 compress:xz > @@ -82,6 +86,8 @@ btrfs-device-add "/dev/sdc1 /dev/sdd1" / > btrfs-device-delete "/dev/sdb1" / > btrfs-device-add "/dev/sdb1" / > btrfs-device-delete "/dev/sdc1 /dev/sdd1" / > +btrfs-replace-start "/dev/sda1" "/dev/sdd1" / force:true > +btrfs-replace-start "/dev/sdd1" "/dev/sda1" / force:true > > mkdir /data4 > tar-in $srcdir/../data/filesanddirs-10M.tar.xz /data4 compress:xz > @@ -90,6 +96,8 @@ btrfs-device-add "/dev/sdc1 /dev/sdd1" / > btrfs-device-delete "/dev/sdb1" / > btrfs-device-add "/dev/sdb1" / > btrfs-device-delete "/dev/sdc1 /dev/sdd1" / > +btrfs-replace-start "/dev/sda1" "/dev/sdd1" / force:true > +btrfs-replace-start "/dev/sdd1" "/dev/sda1" / force:true What are these tests supposed to check? Other than calling btrfs-replace-start and checking it does not fail, how can the result of this operation be actually checked?

Thanks,