size_sourcedir() uses shockingly bad code to try and estimate the size
of the files and directories in a subtree.
- Its use of snprintf(), strcat(), and sscanf() with arbitrarily small
on-stack buffers manages to overflow the stack a few times when given
long file names.
$ BIG=$(perl -e 'print "a" x 200')
$ mkdir -p /tmp/$BIG/$BIG/$BIG/$BIG/$BIG
$ mkfs.btrfs /tmp/img -r /tmp/$BIG/$BIG/$BIG/$BIG/$BIG
*** stack smashing detected ***: mkfs.btrfs terminated
- It passes raw paths to system() allowing interpreting file names as
shell control characters.
$ mkfs.btrfs /tmp/img -r /tmp/spacey\ dir/
du: cannot access `/tmp/spacey': No such file or directory
du: cannot access `dir/': No such file or directory
- It redirects du output to "temp_file" in the current directory,
allowing overwriting of files through symlinks.
$ echo hi > target
$ ln -s target temp_file
$ mkfs.btrfs /tmp/img -r /tmp/somedir/
$ cat target
3 /tmp/somedir/
This fixes the worst problems while maintaining -r functionality by
tearing out the system() code and using ftw() to walk the source tree
and sum up st.st_size.
Signed-off-by: Zach Brown <zab@redhat.com>
gcc optimizes out the memcpy calls at -O2 and -Os.
Replacing memcpy with memmove does't work - gcc treats memmove
the same way it treats memcpy.
This patch brings in {get|put}_unaligned_le{16|32|64} (using the
packed struct method), and uses them in the failing get/set calls.
On architectures where unaligned accesses are cheap, these unaligned
macros should be optimized out by the compiler.
Signed-off-by: Ben Peddell <klightspeed@killerwolves.net>
The kernel uses unsigned long long for u64, but PPC64 uses unsigned
long by default. This results in compilation warnings such as:
print-tree.c:333: warning: format '%llu' expects type 'long long
unsigned int', but argument 4 has type 'u64'
To fix this, the macro __KERNEL__ needs to be defined before including
the file <asm/types.h>. This can be done by defining the macro in
"kerncompat.h" and making it the first included file in the relevant
header files; this fixes the compiler warnings on PPC64.
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Wade Cline <clinew@linux.vnet.ibm.com>
Check_mount() should also work with multi device filesystems.
This patch adds checks that allow to detect if a file is a device
file used by a mounted single or multi device btrfs or if it is a
regular file used by a loopback device that is part of a mounted
single or multi device btrfs.
The single device checks also work for non-btrfs filesystems.
This might be helpful to prevent users from running btrfs programs
(e.g. mkfs.btrfs) accidentally on a filesystem used somewhere else.
Signed-off-by: Andi Drebes <lists-receive@programmierforen.de>
This commit introduces a new kind of back reference for btrfs metadata.
Once a filesystem has been mounted with this commit, IT WILL NO LONGER
BE MOUNTABLE BY OLDER KERNELS.
The new back ref provides information about pointer's key, level and in which
tree the pointer lives. This information allow us to find the pointer by
searching the tree. The shortcoming of the new back ref is that it only works
for pointers in tree blocks referenced by their owner trees.
This is mostly a problem for snapshots, where resolving one of these fuzzy back
references would be O(number_of_snapshots) and quite slow. The solution used
here is to use the fuzzy back references in the common case where a given tree
block is only referenced by one root, and use the full back references when
multiple roots have a reference
Zach Brown
Ben Peddell
Wade Cline
Andi Drebes
Chris Mason
Shen Feng
Yan