Dynamically grow the block zeroing buffer to a maximum of 4MB, and
allow callers to provide their own zeroed buffer.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
lib/ext2fs/alloc.c | 2 +-
lib/ext2fs/ext2fs.h | 3 ++
lib/ext2fs/mkjournal.c | 62 ++++++++++++++++++++++++++++++++++++++----------
3 files changed, 53 insertions(+), 14 deletions(-)
diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index 54535c4..cb778f7 100644
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -203,7 +203,7 @@ errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal,
goto fail;
}
- retval = ext2fs_zero_blocks2(fs, block, 1, NULL, NULL);
+ retval = ext2fs_zero_blocks3(fs, block, 1, NULL, NULL, block_buf);
if (retval)
goto fail;
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 506d43b..f9599a3 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1491,6 +1491,9 @@ extern errcode_t ext2fs_zero_blocks(ext2_filsys fs, blk_t blk, int num,
blk_t *ret_blk, int *ret_count);
extern errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
blk64_t *ret_blk, int *ret_count);
+extern errcode_t ext2fs_zero_blocks3(ext2_filsys fs, blk64_t blk, int num,
+ blk64_t *ret_blk, int *ret_count,
+ const void *block_buf);
extern errcode_t ext2fs_create_journal_superblock(ext2_filsys fs,
__u32 num_blocks, int flags,
char **ret_jsb);
diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index e8f8b30..fdd788b 100644
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -148,12 +148,14 @@ errfree:
* attempt to free the static zeroizing buffer. (This is to keep
* programs that check for memory leaks happy.)
*/
-#define STRIDE_LENGTH (4194304 / fs->blocksize)
-errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
- blk64_t *ret_blk, int *ret_count)
+#define MAX_STRIDE_LENGTH (4194304 / fs->blocksize)
+errcode_t ext2fs_zero_blocks3(ext2_filsys fs, blk64_t blk, int num,
+ blk64_t *ret_blk, int *ret_count,
+ const void *block_buf)
{
int j, count;
- static char *buf;
+ static void *buf;
+ static unsigned stride_length;
errcode_t retval;
/* If fs is null, clean up the static buffer and return */
@@ -164,24 +166,52 @@ errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
}
return 0;
}
+
+ /* Deal with zeroing less than 1 block */
+ if (num <= 0)
+ return 0;
+
+ /* If the user gave us a buffer, write that out */
+ if (block_buf) {
+ retval = io_channel_write_blk64(fs->io, blk, num, block_buf);
+ if (retval) {
+ if (ret_count)
+ *ret_count = num;
+ if (ret_blk)
+ *ret_blk = blk;
+ }
+
+ return retval;
+ }
+
/* Allocate the zeroizing buffer if necessary */
- if (!buf) {
- buf = malloc(fs->blocksize * STRIDE_LENGTH);
- if (!buf)
- return ENOMEM;
- memset(buf, 0, fs->blocksize * STRIDE_LENGTH);
+ if (num > stride_length) {
+ void *p;
+ unsigned new_stride = num;
+
+ if (new_stride > MAX_STRIDE_LENGTH)
+ new_stride = MAX_STRIDE_LENGTH;
+ if (new_stride == stride_length)
+ goto skip_alloc;
+ p = realloc(buf, fs->blocksize * new_stride);
+ if (!p)
+ return EXT2_ET_NO_MEMORY;
+ buf = p;
+ stride_length = new_stride;
+ memset(buf, 0, fs->blocksize * stride_length);
}
+skip_alloc:
/* OK, do the write loop */
j=0;
while (j < num) {
- if (blk % STRIDE_LENGTH) {
- count = STRIDE_LENGTH - (blk % STRIDE_LENGTH);
+ if (blk % stride_length) {
+ count = stride_length - (blk % stride_length);
if (count > (num - j))
count = num - j;
} else {
count = num - j;
- if (count > STRIDE_LENGTH)
- count = STRIDE_LENGTH;
+ if (count > stride_length)
+ count = stride_length;
}
retval = io_channel_write_blk64(fs->io, blk, count, buf);
if (retval) {
@@ -196,6 +226,12 @@ errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
return 0;
}
+errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num,
+ blk64_t *ret_blk, int *ret_count)
+{
+ return ext2fs_zero_blocks3(fs, blk, num, ret_blk, ret_count, NULL);
+}
+
errcode_t ext2fs_zero_blocks(ext2_filsys fs, blk_t blk, int num,
blk_t *ret_blk, int *ret_count)
{
--
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