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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-10-20 00:10:27 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-10-20 00:10:27 -0300
commitd0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch)
tree7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /drivers/mtd/ubi/attach.c
parente914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff)
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'drivers/mtd/ubi/attach.c')
-rw-r--r--drivers/mtd/ubi/attach.c141
1 files changed, 106 insertions, 35 deletions
diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
index c1aaf0336..903becd31 100644
--- a/drivers/mtd/ubi/attach.c
+++ b/drivers/mtd/ubi/attach.c
@@ -175,6 +175,40 @@ static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
}
/**
+ * add_fastmap - add a Fastmap related physical eraseblock.
+ * @ai: attaching information
+ * @pnum: physical eraseblock number the VID header came from
+ * @vid_hdr: the volume identifier header
+ * @ec: erase counter of the physical eraseblock
+ *
+ * This function allocates a 'struct ubi_ainf_peb' object for a Fastamp
+ * physical eraseblock @pnum and adds it to the 'fastmap' list.
+ * Such blocks can be Fastmap super and data blocks from both the most
+ * recent Fastmap we're attaching from or from old Fastmaps which will
+ * be erased.
+ */
+static int add_fastmap(struct ubi_attach_info *ai, int pnum,
+ struct ubi_vid_hdr *vid_hdr, int ec)
+{
+ struct ubi_ainf_peb *aeb;
+
+ aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
+ if (!aeb)
+ return -ENOMEM;
+
+ aeb->pnum = pnum;
+ aeb->vol_id = be32_to_cpu(vidh->vol_id);
+ aeb->sqnum = be64_to_cpu(vidh->sqnum);
+ aeb->ec = ec;
+ list_add(&aeb->u.list, &ai->fastmap);
+
+ dbg_bld("add to fastmap list: PEB %d, vol_id %d, sqnum: %llu", pnum,
+ aeb->vol_id, aeb->sqnum);
+
+ return 0;
+}
+
+/**
* validate_vid_hdr - check volume identifier header.
* @ubi: UBI device description object
* @vid_hdr: the volume identifier header to check
@@ -803,13 +837,26 @@ out_unlock:
return err;
}
+static bool vol_ignored(int vol_id)
+{
+ switch (vol_id) {
+ case UBI_LAYOUT_VOLUME_ID:
+ return true;
+ }
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+ return ubi_is_fm_vol(vol_id);
+#else
+ return false;
+#endif
+}
+
/**
* scan_peb - scan and process UBI headers of a PEB.
* @ubi: UBI device description object
* @ai: attaching information
* @pnum: the physical eraseblock number
- * @vid: The volume ID of the found volume will be stored in this pointer
- * @sqnum: The sqnum of the found volume will be stored in this pointer
+ * @fast: true if we're scanning for a Fastmap
*
* This function reads UBI headers of PEB @pnum, checks them, and adds
* information about this PEB to the corresponding list or RB-tree in the
@@ -817,9 +864,9 @@ out_unlock:
* successfully handled and a negative error code in case of failure.
*/
static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
- int pnum, int *vid, unsigned long long *sqnum)
+ int pnum, bool fast)
{
- long long uninitialized_var(ec);
+ long long ec;
int err, bitflips = 0, vol_id = -1, ec_err = 0;
dbg_bld("scan PEB %d", pnum);
@@ -935,6 +982,20 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
*/
ai->maybe_bad_peb_count += 1;
case UBI_IO_BAD_HDR:
+ /*
+ * If we're facing a bad VID header we have to drop *all*
+ * Fastmap data structures we find. The most recent Fastmap
+ * could be bad and therefore there is a chance that we attach
+ * from an old one. On a fine MTD stack a PEB must not render
+ * bad all of a sudden, but the reality is different.
+ * So, let's be paranoid and help finding the root cause by
+ * falling back to scanning mode instead of attaching with a
+ * bad EBA table and cause data corruption which is hard to
+ * analyze.
+ */
+ if (fast)
+ ai->force_full_scan = 1;
+
if (ec_err)
/*
* Both headers are corrupted. There is a possibility
@@ -991,21 +1052,15 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
}
vol_id = be32_to_cpu(vidh->vol_id);
- if (vid)
- *vid = vol_id;
- if (sqnum)
- *sqnum = be64_to_cpu(vidh->sqnum);
- if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
+ if (vol_id > UBI_MAX_VOLUMES && !vol_ignored(vol_id)) {
int lnum = be32_to_cpu(vidh->lnum);
/* Unsupported internal volume */
switch (vidh->compat) {
case UBI_COMPAT_DELETE:
- if (vol_id != UBI_FM_SB_VOLUME_ID
- && vol_id != UBI_FM_DATA_VOLUME_ID) {
- ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",
- vol_id, lnum);
- }
+ ubi_msg(ubi, "\"delete\" compatible internal volume %d:%d found, will remove it",
+ vol_id, lnum);
+
err = add_to_list(ai, pnum, vol_id, lnum,
ec, 1, &ai->erase);
if (err)
@@ -1037,7 +1092,12 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
if (ec_err)
ubi_warn(ubi, "valid VID header but corrupted EC header at PEB %d",
pnum);
- err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
+
+ if (ubi_is_fm_vol(vol_id))
+ err = add_fastmap(ai, pnum, vidh, ec);
+ else
+ err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
+
if (err)
return err;
@@ -1186,6 +1246,10 @@ static void destroy_ai(struct ubi_attach_info *ai)
list_del(&aeb->u.list);
kmem_cache_free(ai->aeb_slab_cache, aeb);
}
+ list_for_each_entry_safe(aeb, aeb_tmp, &ai->fastmap, u.list) {
+ list_del(&aeb->u.list);
+ kmem_cache_free(ai->aeb_slab_cache, aeb);
+ }
/* Destroy the volume RB-tree */
rb = ai->volumes.rb_node;
@@ -1245,7 +1309,7 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
cond_resched();
dbg_gen("process PEB %d", pnum);
- err = scan_peb(ubi, ai, pnum, NULL, NULL);
+ err = scan_peb(ubi, ai, pnum, false);
if (err < 0)
goto out_vidh;
}
@@ -1311,6 +1375,7 @@ static struct ubi_attach_info *alloc_ai(void)
INIT_LIST_HEAD(&ai->free);
INIT_LIST_HEAD(&ai->erase);
INIT_LIST_HEAD(&ai->alien);
+ INIT_LIST_HEAD(&ai->fastmap);
ai->volumes = RB_ROOT;
ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
sizeof(struct ubi_ainf_peb),
@@ -1326,7 +1391,7 @@ static struct ubi_attach_info *alloc_ai(void)
#ifdef CONFIG_MTD_UBI_FASTMAP
/**
- * scan_fastmap - try to find a fastmap and attach from it.
+ * scan_fast - try to find a fastmap and attach from it.
* @ubi: UBI device description object
* @ai: attach info object
*
@@ -1337,52 +1402,58 @@ static struct ubi_attach_info *alloc_ai(void)
*/
static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
{
- int err, pnum, fm_anchor = -1;
- unsigned long long max_sqnum = 0;
+ int err, pnum;
+ struct ubi_attach_info *scan_ai;
err = -ENOMEM;
+ scan_ai = alloc_ai();
+ if (!scan_ai)
+ goto out;
+
ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
if (!ech)
- goto out;
+ goto out_ai;
vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
if (!vidh)
goto out_ech;
for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
- int vol_id = -1;
- unsigned long long sqnum = -1;
cond_resched();
dbg_gen("process PEB %d", pnum);
- err = scan_peb(ubi, *ai, pnum, &vol_id, &sqnum);
+ err = scan_peb(ubi, scan_ai, pnum, true);
if (err < 0)
goto out_vidh;
-
- if (vol_id == UBI_FM_SB_VOLUME_ID && sqnum > max_sqnum) {
- max_sqnum = sqnum;
- fm_anchor = pnum;
- }
}
ubi_free_vid_hdr(ubi, vidh);
kfree(ech);
- if (fm_anchor < 0)
- return UBI_NO_FASTMAP;
+ if (scan_ai->force_full_scan)
+ err = UBI_NO_FASTMAP;
+ else
+ err = ubi_scan_fastmap(ubi, *ai, scan_ai);
- destroy_ai(*ai);
- *ai = alloc_ai();
- if (!*ai)
- return -ENOMEM;
+ if (err) {
+ /*
+ * Didn't attach via fastmap, do a full scan but reuse what
+ * we've aready scanned.
+ */
+ destroy_ai(*ai);
+ *ai = scan_ai;
+ } else
+ destroy_ai(scan_ai);
- return ubi_scan_fastmap(ubi, *ai, fm_anchor);
+ return err;
out_vidh:
ubi_free_vid_hdr(ubi, vidh);
out_ech:
kfree(ech);
+out_ai:
+ destroy_ai(scan_ai);
out:
return err;
}