From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH 2/2] state: storage: direct: skip writing meta data if this makes data fit
Date: Tue, 26 Sep 2017 22:58:43 +0200 [thread overview]
Message-ID: <20170926205843.5910-3-u.kleine-koenig@pengutronix.de> (raw)
In-Reply-To: <20170926205843.5910-1-u.kleine-koenig@pengutronix.de>
When a direct bucket is read it handles missing meta data just fine for
compatibility reasons. This allows to skip writing meta data if that
makes the data small enough to fit in the bucket to be written.
The motivation for this change is that the storage format in
pre-mainline state didn't use meta data and some machines still have to
stick to this format. For these the stride size exactly fits the data
size such that there is no place for additional meta data and so the
data is written in the old format.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
common/state/backend_bucket_direct.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/common/state/backend_bucket_direct.c b/common/state/backend_bucket_direct.c
index 4465ed0e4115..8bf9a945643c 100644
--- a/common/state/backend_bucket_direct.c
+++ b/common/state/backend_bucket_direct.c
@@ -102,8 +102,14 @@ static int state_backend_bucket_direct_write(struct state_backend_storage_bucket
get_bucket_direct(bucket);
int ret;
struct state_backend_storage_bucket_direct_meta meta;
+ int write_meta = 1;
- if (len > direct->max_size - sizeof(meta))
+ if (len > direct->max_size - sizeof(meta)) {
+ dev_info(direct->dev, "skip writing metadata because of size constraints\n");
+ write_meta = 0;
+ }
+
+ if (len > direct->max_size)
return -E2BIG;
ret = lseek(direct->fd, direct->offset, SEEK_SET);
@@ -112,12 +118,15 @@ static int state_backend_bucket_direct_write(struct state_backend_storage_bucket
return ret;
}
- meta.magic = direct_magic;
- meta.written_length = len;
- ret = write_full(direct->fd, &meta, sizeof(meta));
- if (ret < 0) {
- dev_err(direct->dev, "Failed to write metadata to file, %d\n", ret);
- return ret;
+ if (write_meta) {
+ meta.magic = direct_magic;
+ meta.written_length = len;
+ ret = write_full(direct->fd, &meta, sizeof(meta));
+ if (ret < 0) {
+ dev_err(direct->dev,
+ "Failed to write metadata to file, %d\n", ret);
+ return ret;
+ }
}
ret = write_full(direct->fd, buf, len);
--
2.11.0
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
prev parent reply other threads:[~2017-09-26 20:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-26 20:58 [PATCH 0/2] state: add support for pre-mainline state format Uwe Kleine-König
2017-09-26 20:58 ` [PATCH 1/2] state: new backend format "rawcompat" Uwe Kleine-König
2017-09-26 20:58 ` Uwe Kleine-König [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170926205843.5910-3-u.kleine-koenig@pengutronix.de \
--to=u.kleine-koenig@pengutronix.de \
--cc=barebox@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox