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@xxxxxxxxxx>
---
lib/ext2fs/ext2_io.h | 2 ++
lib/ext2fs/unix_io.c | 31 +++++++++++++++++++++++++++++++
2 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/lib/ext2fs/ext2_io.h b/lib/ext2fs/ext2_io.h
index ccc9c8b..c8ec8e5 100644
--- a/lib/ext2fs/ext2_io.h
+++ b/lib/ext2fs/ext2_io.h
@@ -83,6 +83,8 @@ struct struct_io_manager {
int count, void *data);
errcode_t (*write_blk64)(io_channel channel, unsigned long long block,
int count, const void *data);
+ errcode_t (*discard)(io_channel channel, unsigned long long block,
+ unsigned long long count, unsigned int blocksize);
long reserved[16];
};
diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index 1df1fdd..991de50 100644
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -115,6 +115,8 @@ static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
int count, void *data);
static errcode_t unix_write_blk64(io_channel channel, unsigned long long block,
int count, const void *data);
+static errcode_t unix_discard(io_channel channel, unsigned long long block,
+ unsigned long long count, unsigned int blocksize);
static struct struct_io_manager struct_unix_manager = {
EXT2_ET_MAGIC_IO_MANAGER,
@@ -130,6 +132,7 @@ static struct struct_io_manager struct_unix_manager = {
unix_get_stats,
unix_read_blk64,
unix_write_blk64,
+ unix_discard,
};
io_manager unix_io_manager = &struct_unix_manager;
@@ -834,3 +837,31 @@ static errcode_t unix_set_option(io_channel channel, const char *option,
}
return EXT2_ET_INVALID_ARGUMENT;
}
+
+#ifdef __linux__
+
+#ifndef BLKDISCARD
+#define BLKDISCARD _IO(0x12,119)
+#endif
+
+static errcode_t unix_discard(io_channel channel, unsigned long long block,
+ unsigned long long count, unsigned int blocksize)
+{
+ struct unix_private_data *data;
+ __uint64_t range[2];
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct unix_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ range[0] = (__uint64_t)(block);
+ range[1] = (__uint64_t)(count);
+ range[0] *= (__uint64_t)(blocksize);
+ range[1] *= (__uint64_t)(blocksize);
+
+ return ioctl(data->dev, BLKDISCARD, &range);
+}
+
+#else
+#define unix_discard(channel, block, count, blocksize) EXT2_ET_UNIMPLEMENTED
+#endif
--
1.7.2.3
--
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