On Sat, Apr 15, 2017 at 09:41:18AM -0400, Theodore Ts'o wrote:
> Add an extended option, -E no_optimize_extents, as well as a
> e2fsck.conf profile option, to disable extent tree optimization.
>
> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
> ---
> e2fsck/e2fsck.8.in | 4 ++++
> e2fsck/e2fsck.conf.5.in | 4 ++++
> e2fsck/e2fsck.h | 1 +
> e2fsck/extents.c | 3 +++
> e2fsck/unix.c | 8 ++++++++
> 5 files changed, 20 insertions(+)
>
> diff --git a/e2fsck/e2fsck.8.in b/e2fsck/e2fsck.8.in
> index 915273d8..4ad575f4 100644
> --- a/e2fsck/e2fsck.8.in
> +++ b/e2fsck/e2fsck.8.in
> @@ -226,6 +226,10 @@ option may prevent you from further manual data recovery.
> Do not attempt to discard free blocks and unused inode blocks. This option is
> exactly the opposite of discard option. This is set as default.
> .TP
> +.BI no_optimize_extents
> +Do not offer to optimize the extent tree by eliminating unnecessary
> +width or depth.
> +.TP
> .BI readahead_kb
> Use this many KiB of memory to pre-fetch metadata in the hopes of reducing
> e2fsck runtime. By default, this is set to the size of two block groups' inode
> diff --git a/e2fsck/e2fsck.conf.5.in b/e2fsck/e2fsck.conf.5.in
> index 0bfc76ab..94525baf 100644
> --- a/e2fsck/e2fsck.conf.5.in
> +++ b/e2fsck/e2fsck.conf.5.in
> @@ -205,6 +205,10 @@ of that type are squelched. This can be useful if the console is slow
> (i.e., connected to a serial port) and so a large amount of output could
> end up delaying the boot process for a long time (potentially hours).
> .TP
> +.I no_optimize_extents
> +Do not offer to optimize the extent tree by eliminating unnecessary
> +width or depth.
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
/me wonders if there's a way to detect that we're being run by
initscripts/systemd/whatever on a device that is mounted ro, and skip
the optimization step to avoid the reboot.
OTOH I wonder why the initramfs (if available) doesn't just build in
e2fsck and fsck the root device before mounting the fs...
--D
> +.TP
> .I readahead_mem_pct
> Use this percentage of memory to try to read in metadata blocks ahead of the
> main e2fsck thread. This should reduce run times, depending on the speed of
> diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
> index ecd3b1e1..a4b5fb24 100644
> --- a/e2fsck/e2fsck.h
> +++ b/e2fsck/e2fsck.h
> @@ -169,6 +169,7 @@ struct resource_track {
> #define E2F_OPT_DISCARD 0x2000
> #define E2F_OPT_CONVERT_BMAP 0x4000 /* convert blockmap to extent */
> #define E2F_OPT_FIXES_ONLY 0x8000 /* skip all optimizations */
> +#define E2F_OPT_NOOPT_EXTENTS 0x10000 /* don't optimize extents */
>
> /*
> * E2fsck flags
> diff --git a/e2fsck/extents.c b/e2fsck/extents.c
> index 1df31d71..d9410028 100644
> --- a/e2fsck/extents.c
> +++ b/e2fsck/extents.c
> @@ -518,6 +518,9 @@ errcode_t e2fsck_should_rebuild_extents(e2fsck_t ctx,
> if (eti->force_rebuild)
> goto rebuild;
>
> + if (ctx->options & E2F_OPT_NOOPT_EXTENTS)
> + return 0;
> +
> extents_per_block = (ctx->fs->blocksize -
> sizeof(struct ext3_extent_header)) /
> sizeof(struct ext3_extent);
> diff --git a/e2fsck/unix.c b/e2fsck/unix.c
> index b7322bc6..b6025535 100644
> --- a/e2fsck/unix.c
> +++ b/e2fsck/unix.c
> @@ -709,6 +709,9 @@ static void parse_extended_opts(e2fsck_t ctx, const char *opts)
> } else if (strcmp(token, "nodiscard") == 0) {
> ctx->options &= ~E2F_OPT_DISCARD;
> continue;
> + } else if (strcmp(token, "no_optimize_extents") == 0) {
> + ctx->options |= E2F_OPT_NOOPT_EXTENTS;
> + continue;
> } else if (strcmp(token, "log_filename") == 0) {
> if (!arg)
> extended_usage++;
> @@ -1007,6 +1010,11 @@ static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
> if (c)
> verbose = 1;
>
> + profile_get_boolean(ctx->profile, "options", "no_optimize_extents",
> + 0, 0, &c);
> + if (c)
> + ctx->options |= E2F_OPT_NOOPT_EXTENTS;
> +
> if (ctx->readahead_kb == ~0ULL) {
> profile_get_integer(ctx->profile, "options",
> "readahead_mem_pct", 0, -1, &c);
> --
> 2.11.0.rc0.7.gbe5a750
>
