Plumb a new call into the IO manager to support translating
ext2fs_zero_blocks calls into the equivalent FALLOC_FL_ZERO_RANGE
fallocate flag primitive when possible. This patch provides _only_
support for file-based images.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add a readahead method for prefetching ranges of disk blocks. This is
useful for inode table scanning, and other large contiguous ranges of
blocks, and may also prove useful for random block prefetch, since it
will allow reordering of the IO without waiting synchronously for the
reads to complete.
It is currently using the posix_fadvise(POSIX_FADV_WILLNEED)
interface, as this proved most efficient during our testing.
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Create a new function, io_channel_alloc_buf() which allocates I/O
buffers with appropriate alignment if we are using direct I/O. The
original code was sometimes using a larger alignment factor than
necessary, and would always request an aligned memory buffer even when
it was not necessary since the block device was not opened with
O_DIRECT.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The DEFS line in MCONFIG had gotten so long that it exceeded 4k, and
this was starting to cause some tools heartburn. It also made "make
V=1" almost useless, since trying to following the individual commands
run by make was lost in the noise of all of the defines.
So fix this by putting the configure-generated defines in lib/config.h
and the directory pathnames to lib/dirpaths.h.
In addition, clean up some vestigal defines in configure.in and in the
Makefiles to further shorten the cc command lines.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In order to provide generic "discard" function for all e2fsprogs tools
add a discard function prototype into struct_io_manager. Specific
function for specific io managers can be crated that way.
This commit also creates unix_discard function which uses BLKDISCARD
ioctl to discard data blocks on the block device and bind it into
unit_io_manager structure to be available for all e2fsprogs tools.
Note that BLKDISCARD is still Linux specific ioctl, however other
unix systems may provide similar functionality. So far the
unix_discard() remains linux specific hence is embedded in #ifdef
__linux__ macro.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Provide a C language wrapper function for io_channel_read_blk64() and
io_channel_write_blk64() instead of using a C preprocessor macro, with
an fallback to the old 32-bit functions if an application-provided I/O
channel manager doesn't supply 64-bit method functions and the block
numbers can fit in 32-bit integer.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
example, /tmp/test.img?offset=1024. Multiple options can separated using
the & character, although at the moment the only option implemented is
the offset option in the unix_io layer.
Darrick J. Wong