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authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2010-07-30 14:59:50 +0300
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2010-08-02 07:21:19 +0300
commit64d4b4c90a876401e503c3a3260e9d0ed066f271 (patch)
tree4da6a688f44cdec560792a29e24031a00a0696ef /drivers
parent7cdb996ee4d04b5bb2cd544b14e8eb91cfd7fe64 (diff)
downloadkernel-64d4b4c90a876401e503c3a3260e9d0ed066f271.tar.gz
UBI: do not warn unnecessarily
Currently, when UBI attaches an MTD device and cannot reserve all 1% (by default) of PEBs for bad eraseblocks handling, it prints a warning. However, Matthew L. Creech <mlcreech@gmail.com> is not very happy to see this warning, because he did reserve enough of PEB at the beginning, but with time some PEBs became bad. The warning is not necessary in this case. This patch makes UBI print the warning o if this is a new image o of this is used image and the amount of reserved PEBs is only 10% (or less) of the size of the reserved PEB pool. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mtd/ubi/build.c3
-rw-r--r--drivers/mtd/ubi/eba.c42
2 files changed, 41 insertions, 4 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 13b05cb33b08..78ae89488a4f 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -593,6 +593,7 @@ static int attach_by_scanning(struct ubi_device *ubi)
ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
ubi->max_ec = si->max_ec;
ubi->mean_ec = si->mean_ec;
+ ubi_msg("max. sequence number: %llu", si->max_sqnum);
err = ubi_read_volume_table(ubi, si);
if (err)
@@ -981,7 +982,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
ubi_msg("number of PEBs reserved for bad PEB handling: %d",
ubi->beb_rsvd_pebs);
ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
- ubi_msg("image sequence number: %d", ubi->image_seq);
+ ubi_msg("image sequence number: %d", ubi->image_seq);
/*
* The below lock makes sure we do not race with 'ubi_thread()' which
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index b582671ca3a0..fe74749e0dae 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -1166,6 +1166,44 @@ out_unlock_leb:
}
/**
+ * print_rsvd_warning - warn about not having enough reserved PEBs.
+ * @ubi: UBI device description object
+ *
+ * This is a helper function for 'ubi_eba_init_scan()' which is called when UBI
+ * cannot reserve enough PEBs for bad block handling. This function makes a
+ * decision whether we have to print a warning or not. The algorithm is as
+ * follows:
+ * o if this is a new UBI image, then just print the warning
+ * o if this is an UBI image which has already been used for some time, print
+ * a warning only if we can reserve less than 10% of the expected amount of
+ * the reserved PEB.
+ *
+ * The idea is that when UBI is used, PEBs become bad, and the reserved pool
+ * of PEBs becomes smaller, which is normal and we do not want to scare users
+ * with a warning every time they attach the MTD device. This was an issue
+ * reported by real users.
+ */
+static void print_rsvd_warning(struct ubi_device *ubi,
+ struct ubi_scan_info *si)
+{
+ /*
+ * The 1 << 18 (256KiB) number is picked randomly, just a reasonably
+ * large number to distinguish between newly flashed and used images.
+ */
+ if (si->max_sqnum > (1 << 18)) {
+ int min = ubi->beb_rsvd_level / 10;
+
+ if (!min)
+ min = 1;
+ if (ubi->beb_rsvd_pebs > min)
+ return;
+ }
+
+ ubi_warn("cannot reserve enough PEBs for bad PEB handling, reserved %d,"
+ " need %d", ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+}
+
+/**
* ubi_eba_init_scan - initialize the EBA sub-system using scanning information.
* @ubi: UBI device description object
* @si: scanning information
@@ -1237,9 +1275,7 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
if (ubi->avail_pebs < ubi->beb_rsvd_level) {
/* No enough free physical eraseblocks */
ubi->beb_rsvd_pebs = ubi->avail_pebs;
- ubi_warn("cannot reserve enough PEBs for bad PEB "
- "handling, reserved %d, need %d",
- ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+ print_rsvd_warning(ubi, si);
} else
ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;