diff options
| author | Richard Weinberger <richard@nod.at> | 2011-11-02 13:17:27 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-11-11 09:43:35 -0800 |
| commit | 02e66bee63c63c2bec1947553e6c5b58b3f0c67d (patch) | |
| tree | d8f3e5dc1f1f718d52c1c949dfcdc77e891afab3 /arch | |
| parent | 9ae9f13480be10697214ed82f4a0f32681309822 (diff) | |
| download | lwn-02e66bee63c63c2bec1947553e6c5b58b3f0c67d.tar.gz lwn-02e66bee63c63c2bec1947553e6c5b58b3f0c67d.zip | |
um: fix ubd cow size
commit 8535639810e578960233ad39def3ac2157b0c3ec upstream.
ubd_file_size() cannot use ubd_dev->cow.file because at this time
ubd_dev->cow.file is not initialized.
Therefore, ubd_file_size() will always report a wrong disk size when
COW files are used.
Reading from /dev/ubd* would crash the kernel.
We have to read the correct disk size from the COW file's backing
file.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 620f5b70957d..0491e40d6968 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -513,8 +513,37 @@ __uml_exitcall(kill_io_thread); static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) { char *file; + int fd; + int err; + + __u32 version; + __u32 align; + char *backing_file; + time_t mtime; + unsigned long long size; + int sector_size; + int bitmap_offset; + + if (ubd_dev->file && ubd_dev->cow.file) { + file = ubd_dev->cow.file; + + goto out; + } - file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; + fd = os_open_file(ubd_dev->file, global_openflags, 0); + if (fd < 0) + return fd; + + err = read_cow_header(file_reader, &fd, &version, &backing_file, \ + &mtime, &size, §or_size, &align, &bitmap_offset); + os_close_file(fd); + + if(err == -EINVAL) + file = ubd_dev->file; + else + file = backing_file; + +out: return os_file_size(file, size_out); } |