In __dbuf_hold_impl(), if a buffer is currently syncing and is still
referenced from db_data, a copy is made in case it is dirtied again in
the txg. Previously, the buffer for the copy was simply allocated with
arc_alloc_buf() which doesn't handle compressed or encrypted buffers
(which are a special case of a compressed buffer). The result was
typically an invalid memory access because the newly-allocated buffer
was of the uncompressed size.
This commit fixes the problem by handling the 2 compressed cases,
encrypted and unencrypted, respectively, with arc_alloc_raw_buf() and
arc_alloc_compressed_buf().
Although using the proper allocation functions fixes the invalid memory
access by allocating a buffer of the compressed size, another unrelated
issue made it impossible to properly detect compressed buffers in the
first place. The header's compression flag was set to ZIO_COMPRESS_OFF
in arc_write() when it was possible that an attached buffer was actually
compressed. This commit adds logic to only set ZIO_COMPRESS_OFF in
the non-ZIO_RAW case which wil handle both cases of compressed buffers
(encrypted or unencrypted).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#5742Closes#6797
Tim Chase
71a24c3c52