marko10_000
/
btrfs-progs
forked from Mirrors/btrfs-progs
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

btrfs-progs: disk-io: Fix read_extent_data() error handler for missing device 

When device is missing, read_extent_data() (function exported from old
btrfs check code) has the following problems:

1) Modifies @len parameter if device is missing
   If device returned in @multi is missing, @len can be larger than
   @max_len (originl length).

   This could confuse caller and underflow in the read loop.

2) Still returns 0 for missing device
   It only handles read error, missing device is not handled and 0 is
   returned.

3) Wrong check for device->fd
   In fact, 0 is also a valid fd.
   Although not possible under most cases, but still needs fix.

Fix them all.

Fixes: 1bad2f2f2d ("Btrfs-progs: fsck: add an option to check data csums")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
master
Qu Wenruo 2018-03-30 15:35:26 +08:00 committed by David Sterba
parent 3f42d56fcb
commit 64f3dc0136
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
disk-io.c
View File

@ -396,10 +396,12 @@ int read_extent_data(struct btrfs_fs_info *fs_info, char *data, u64 logical,
}
device = multi->stripes[0].dev;
if (device->fd <= 0)
goto err;
if (*len > max_len)
*len = max_len;
if (device->fd < 0) {
ret = -EIO;
goto err;
}
ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
if (ret != *len)