diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2020-04-25 11:41:24 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-04-25 11:46:07 -0400 |
| commit | 86d6153417ddaccbe3d1f4466a374716006581f4 (patch) | |
| tree | 275e41734eccc1a85c3d8118986d85186d1cdeb5 | |
| parent | 2f6fd5da81a78aa45d750d8248b25171b8ad9dcd (diff) | |
| download | e2fsprogs-86d6153417ddaccbe3d1f4466a374716006581f4.tar.gz | |
libext2fs: batch calls to ext2fs_zero_blocks2()
When allocating blocks for an indirect block mapped file, accumulate
blocks to be zero'ed and then call ext2fs_zero_blocks2() to zero them
in large chunks instead of block by block.
This significantly speeds up mkfs.ext3 since we don't send a large
number of ZERO_RANGE requests to the kernel, and while the kernel does
batch write requests, it is not batching ZERO_RANGE requests. It's
more efficient to batch in userspace in any case, since it avoids
unnecessary system calls.
Reported-by: Mario Schuknecht <mario.schuknecht@dresearch-fe.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | lib/ext2fs/fallocate.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/lib/ext2fs/fallocate.c b/lib/ext2fs/fallocate.c index 31e47f8de..5cde7d5c2 100644 --- a/lib/ext2fs/fallocate.c +++ b/lib/ext2fs/fallocate.c @@ -805,7 +805,8 @@ errcode_t ext2fs_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino, blk64_t start, blk64_t len) { struct ext2_inode inode_buf; - blk64_t blk, x; + blk64_t blk, x, zero_blk, last = 0; + int zero_len = 0; errcode_t err; if (((flags & EXT2_FALLOCATE_FORCE_INIT) && @@ -841,15 +842,32 @@ errcode_t ext2fs_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino, if (x) continue; - err = ext2fs_bmap2(fs, ino, inode, NULL, - BMAP_ALLOC | BMAP_UNINIT | BMAP_ZERO, blk, - 0, &x); + err = ext2fs_bmap2(fs, ino, inode, NULL, BMAP_ALLOC, + blk, 0, &x); if (err) - return err; + goto errout; + if ((zero_len && (x != last+1)) || + (zero_len >= 65536)) { + err = ext2fs_zero_blocks2(fs, zero_blk, zero_len, + NULL, NULL); + zero_len = 0; + if (err) + goto errout; + } + if (zero_len == 0) { + zero_blk = x; + zero_len = 1; + } else { + zero_len++; + } + last = x; } out: if (inode == &inode_buf) ext2fs_write_inode(fs, ino, inode); +errout: + if (zero_len) + ext2fs_zero_blocks2(fs, zero_blk, zero_len, NULL, NULL); return err; } |