libext2fs: factor out I/O buffer allocation
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>
diff --git a/lib/ext2fs/ext2_io.h b/lib/ext2fs/ext2_io.h
index 95b8de3..1894fb8 100644
--- a/lib/ext2fs/ext2_io.h
+++ b/lib/ext2fs/ext2_io.h
@@ -122,6 +122,8 @@
extern errcode_t io_channel_discard(io_channel channel,
unsigned long long block,
unsigned long long count);
+extern errcode_t io_channel_alloc_buf(io_channel channel,
+ int count, void *ptr);
/* unix_io.c */
extern io_manager unix_io_manager;
diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c
index 6c524ff..77fc447 100644
--- a/lib/ext2fs/inode.c
+++ b/lib/ext2fs/inode.c
@@ -157,8 +157,8 @@
(fs->blocksize / scan->inode_size - 1)) *
scan->inode_size / fs->blocksize;
}
- retval = ext2fs_get_memalign(scan->inode_buffer_blocks * fs->blocksize,
- fs->blocksize, &scan->inode_buffer);
+ retval = io_channel_alloc_buf(fs->io, scan->inode_buffer_blocks,
+ &scan->inode_buffer);
scan->done_group = 0;
scan->done_group_data = 0;
scan->bad_block_ptr = 0;
diff --git a/lib/ext2fs/io_manager.c b/lib/ext2fs/io_manager.c
index 25df59e..34e4859 100644
--- a/lib/ext2fs/io_manager.c
+++ b/lib/ext2fs/io_manager.c
@@ -111,3 +111,20 @@
return EXT2_ET_UNIMPLEMENTED;
}
+
+errcode_t io_channel_alloc_buf(io_channel io, int count, void *ptr)
+{
+ size_t size;
+
+ if (count == 0)
+ size = io->block_size;
+ else if (count > 0)
+ size = io->block_size * count;
+ else
+ size = -count;
+
+ if (io->align)
+ return ext2fs_get_memalign(size, io->align, ptr);
+ else
+ return ext2fs_get_mem(size, ptr);
+}
diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index 220d954..482e4ab 100644
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -144,7 +144,7 @@
goto cleanup;
fs->image_io = fs->io;
fs->io->app_data = fs;
- retval = ext2fs_get_memalign(SUPERBLOCK_SIZE, 512, &fs->super);
+ retval = io_channel_alloc_buf(fs->io, -SUPERBLOCK_SIZE, &fs->super);
if (retval)
goto cleanup;
if (flags & EXT2_FLAG_IMAGE_FILE) {
diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
index 81e09c0..53f6ec4 100644
--- a/lib/ext2fs/rw_bitmaps.c
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -53,8 +53,7 @@
inode_nbytes = block_nbytes = 0;
if (do_block) {
block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
- retval = ext2fs_get_memalign(fs->blocksize, fs->blocksize,
- &block_buf);
+ retval = io_channel_alloc_buf(fs->io, 0, &block_buf);
if (retval)
goto errout;
memset(block_buf, 0xff, fs->blocksize);
@@ -62,8 +61,7 @@
if (do_inode) {
inode_nbytes = (size_t)
((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
- retval = ext2fs_get_memalign(fs->blocksize, fs->blocksize,
- &inode_buf);
+ retval = io_channel_alloc_buf(fs->io, 0, &inode_buf);
if (retval)
goto errout;
memset(inode_buf, 0xff, fs->blocksize);
@@ -186,13 +184,7 @@
retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
if (retval)
goto cleanup;
- if (do_image)
- retval = ext2fs_get_mem(fs->blocksize, &block_bitmap);
- else
- retval = ext2fs_get_memalign(fs->blocksize,
- fs->blocksize,
- &block_bitmap);
-
+ retval = io_channel_alloc_buf(fs->io, 0, &block_bitmap);
if (retval)
goto cleanup;
} else
@@ -205,7 +197,7 @@
retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
if (retval)
goto cleanup;
- retval = ext2fs_get_mem(fs->blocksize, &inode_bitmap);
+ retval = io_channel_alloc_buf(fs->io, 0, &inode_bitmap);
if (retval)
goto cleanup;
} else
diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index 8319eba..2ce0563 100644
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -316,17 +316,14 @@
cache->in_use = 0;
if (cache->buf)
ext2fs_free_mem(&cache->buf);
- retval = ext2fs_get_memalign(channel->block_size,
- channel->align, &cache->buf);
+ retval = io_channel_alloc_buf(channel, 0, &cache->buf);
if (retval)
return retval;
}
if (channel->align) {
if (data->bounce)
ext2fs_free_mem(&data->bounce);
- retval = ext2fs_get_memalign(channel->block_size,
- channel->align,
- &data->bounce);
+ retval = io_channel_alloc_buf(channel, 0, &data->bounce);
}
return retval;
}