2019-11-21 12:06:40

by Artem Blagodarenko

[permalink] [raw]
Subject: [REF] LUS-6746 debugfs: fake_fill_fs to fragment filesystem

From: Vladimir Saveliev <[email protected]>

New command is added to debugfs: fake_fill_fs <filling in %>

This command finds free blocks on a filesystem and mark as in use
specified fraction of those.

Example: debugfs -w -R 'fake_fill_fs 50' <device>

This can be to used in order to quickly fragment a filesystem which
may useful for block allocation improvement estimation.

Use it carefully, there is no way to recover free space but using
e2fsck.

Change-Id: Ib7ce7794eefac2726fef334810a5832d52a90398
Signed-off-by: Vladimir Saveliev <[email protected]>
Signed-off-by: Artem Blagodarenko <[email protected]>
Cray-bug-id: LUS-6746
---
debugfs/debug_cmds.ct | 2 ++
debugfs/debugfs.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 32 insertions(+)

diff --git a/debugfs/debug_cmds.ct b/debugfs/debug_cmds.ct
index 1ff6c9dc..12557888 100644
--- a/debugfs/debug_cmds.ct
+++ b/debugfs/debug_cmds.ct
@@ -229,5 +229,7 @@ request do_journal_write, "Write a transaction to the journal",
request do_journal_run, "Recover the journal",
journal_run, jr;

+request do_fake_fill_fs, "Make the filesystem to look as if it was full",
+ fake_fill_fs;
end;

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index 9b701455..25731883 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -2209,6 +2209,36 @@ err:
ext2fs_free_mem(&buf);
}

+void do_fake_fill_fs(int argc, char *argv[])
+{
+ __u64 block_count, i;
+ unsigned long v;
+ char *tmp;
+ int f;
+
+ if (common_args_process(argc, argv, 2, 2, argv[0],
+ "filling(%)", CHECK_FS_BITMAPS))
+ return;
+ if (check_fs_read_write(argv[0]))
+ return;
+ v = strtoul(argv[1], &tmp, 0);
+ if (v < 1 || v > 100) {
+ com_err("argv[0]", 0, "filling [1-100]");
+ }
+
+ block_count = ext2fs_blocks_count(current_fs->super);
+ for (i = 1, f = 0; i < block_count; i++) {
+ if (!ext2fs_test_block_bitmap2(current_fs->block_map, i)) {
+ f %= 100;
+ if (f < v)
+ ext2fs_block_alloc_stats2(current_fs, i, +1);
+ f ++;
+ }
+ }
+
+ ext2fs_mark_bb_dirty(current_fs);
+}
+
#ifndef READ_ONLY
void do_set_current_time(int argc, char *argv[],
int sci_idx EXT2FS_ATTR((unused)),
--
2.14.3 (Apple Git-98)