| Message ID | 20170222225637.21858-2-benedikt.morbach@googlemail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, Feb 22, 2017 at 11:56:37PM +0100, Benedikt Morbach wrote: > testcase: > # ro subvol /src/parent > # rw subvol /src/foo > clone /src/parent/file /src/foo/file > subvol snapshot -r /src/foo /src/foo.snap > > # generates a "clone parent/file -> foo.snap/file" send command > send -p /src/parent /src/foo.snap > > # target fs: > # dest/ > # |--- parent/... > # mounted with -o subvol=dest, such that "parent" is at <target>/parent > receive <target> > > result: > ERROR: cannot open dest/parent/file: No such file or directory > > expected: > "dest/" get's stripped from the clone source path to get the actual > path in the target fs, if reachable from the mount point/chroot. > > This is exactly what process_snapshot does, which gets called on > _every_ incremental receive and I'm quite certain is correct in > doing so > > Signed-off-by: Benedikt Morbach <benedikt.morbach@googlemail.com> 1-2 applied, thanks. > --- > > Hi, > > I first tried fixing this ages ago with [1], which was met with some scepticism. > While that patch wasn't 100% correct I believe this is, and as mentioned it does > exacly the same thing as process_snapshot because that has the exact same problem. > > An fstest to reproduce this will be following shortly I'll add an adapted version of the test script to progs as I'd like to be able to test any changes to receive from there. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/cmds-receive.c b/cmds-receive.c index 790218c..01345a4 100644 --- a/cmds-receive.c +++ b/cmds-receive.c @@ -782,7 +782,24 @@ static int process_clone(const char *path, u64 offset, u64 len, r->subvol_parent_name); } }*/ - subvol_path = strdup(si->path); + + /* strip the subvolume that we are receiving to from the start of subvol_path */ + if (rctx->full_root_path) { + size_t root_len = strlen(rctx->full_root_path); + size_t sub_len = strlen(si->path); + + if (sub_len > root_len && + strstr(si->path, rctx->full_root_path) == si->path && + si->path[root_len] == '/') { + subvol_path = strdup(si->path + root_len + 1); + } else { + error("clone: source subvol path %s unreachable from %s", + si->path, rctx->full_root_path); + goto out; + } + } else { + subvol_path = strdup(si->path); + } } ret = path_cat_out(full_clone_path, subvol_path, clone_path);
testcase: # ro subvol /src/parent # rw subvol /src/foo clone /src/parent/file /src/foo/file subvol snapshot -r /src/foo /src/foo.snap # generates a "clone parent/file -> foo.snap/file" send command send -p /src/parent /src/foo.snap # target fs: # dest/ # |--- parent/... # mounted with -o subvol=dest, such that "parent" is at <target>/parent receive <target> result: ERROR: cannot open dest/parent/file: No such file or directory expected: "dest/" get's stripped from the clone source path to get the actual path in the target fs, if reachable from the mount point/chroot. This is exactly what process_snapshot does, which gets called on _every_ incremental receive and I'm quite certain is correct in doing so Signed-off-by: Benedikt Morbach <benedikt.morbach@googlemail.com> --- Hi, I first tried fixing this ages ago with [1], which was met with some scepticism. While that patch wasn't 100% correct I believe this is, and as mentioned it does exacly the same thing as process_snapshot because that has the exact same problem. An fstest to reproduce this will be following shortly [1] https://patchwork.kernel.org/patch/9177155/ cmds-receive.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)