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4fdb688c70
When not using the NO_HOLES feature we were not marking the destination's
file range as written after cloning an inline extent into it. This can
lead to a data loss if the current destination file size is smaller than
the source file's size.
Example:
$ mkfs.btrfs -f -O ^no-holes /dev/sdc
$ mount /mnt/sdc /mnt
$ echo "hello world" > /mnt/foo
$ cp --reflink=always /mnt/foo /mnt/bar
$ rm -f /mnt/foo
$ umount /mnt
$ mount /mnt/sdc /mnt
$ cat /mnt/bar
$
$ stat -c %s /mnt/bar
0
# -> the file is empty, since we deleted foo, the data lost is forever
Fix that by calling btrfs_inode_set_file_extent_range() after cloning an
inline extent.
A test case for fstests will follow soon.
Link: https://lore.kernel.org/linux-btrfs/20200404193846.GA432065@latitude/
Reported-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Fixes: 9ddc959e80 ("btrfs: use the file extent tree infrastructure")
Tested-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.