ubi: fastmap: Check each mapping only once

Maintain a bitmap to keep track of which LEB->PEB mapping
was checked already.
That way we have to read back VID headers only once.

Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 74425af840d646af7458d0e571704c58eb06a18c..d2a726654ff1182e961f22ff365dc461996b7204 100644 (file)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -526,6 +526,7 @@ void ubi_free_internal_volumes(struct ubi_device *ubi)
        for (i = ubi->vtbl_slots;
             i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
                ubi_eba_replace_table(ubi->volumes[i], NULL);
+               ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
                kfree(ubi->volumes[i]);
        }
 }

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 593a4f9d97e3d5f0100d3065d45b9d6707f72549..1ceab201a27b5414a274e27c96c4b2e8de0cac4f 100644 (file)
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -517,6 +517,9 @@ static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnu
        if (!ubi->fast_attach)
                return 0;
 
+       if (!vol->checkmap || test_bit(lnum, vol->checkmap))
+               return 0;
+
        vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
        if (!vidb)
                return -ENOMEM;
@@ -551,6 +554,7 @@ static int check_mapping(struct ubi_device *ubi, struct ubi_volume *vol, int lnu
                goto out_free;
        }
 
+       set_bit(lnum, vol->checkmap);
        err = 0;
 
 out_free:

diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index 91705962ba7353c04e5a61fc2915e5a51a730e33..462526a105371e26e2059f280f21801a57af22c3 100644 (file)
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -1100,6 +1100,26 @@ free_fm_sb:
        goto out;
 }
 
+int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
+{
+       struct ubi_device *ubi = vol->ubi;
+
+       if (!ubi->fast_attach)
+               return 0;
+
+       vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
+                               GFP_KERNEL);
+       if (!vol->checkmap)
+               return -ENOMEM;
+
+       return 0;
+}
+
+void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
+{
+       kfree(vol->checkmap);
+}
+
 /**
  * ubi_write_fastmap - writes a fastmap.
  * @ubi: UBI device object

diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 5fe62653995ea308d2953c707c177857b5e7911f..f5ba97c46160ac18ba73e46d7277b64ebddbf41e 100644 (file)
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -334,6 +334,9 @@ struct ubi_eba_leb_desc {
  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
  * @direct_writes: %1 if direct writes are enabled for this volume
  *
+ * @checkmap: bitmap to remember which PEB->LEB mappings got checked,
+ *            protected by UBI LEB lock tree.
+ *
  * The @corrupted field indicates that the volume's contents is corrupted.
  * Since UBI protects only static volumes, this field is not relevant to
  * dynamic volumes - it is user's responsibility to assure their data
@@ -377,6 +380,10 @@ struct ubi_volume {
        unsigned int updating:1;
        unsigned int changing_leb:1;
        unsigned int direct_writes:1;
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+       unsigned long *checkmap;
+#endif
 };
 
 /**
@@ -965,8 +972,12 @@ size_t ubi_calc_fm_size(struct ubi_device *ubi);
 int ubi_update_fastmap(struct ubi_device *ubi);
 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
                     struct ubi_attach_info *scan_ai);
+int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count);
+void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol);
 #else
 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
+int static inline ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count) { return 0; }
+static inline void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol) {}
 #endif
 
 /* block.c */

diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 3fd8d7ff7a02ff7bc63a36418ab6734a9f0650de..0be516780e929daa3ff31c9d73c30bbd38493da4 100644 (file)
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -139,6 +139,7 @@ static void vol_release(struct device *dev)
        struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
 
        ubi_eba_replace_table(vol, NULL);
+       ubi_fastmap_destroy_checkmap(vol);
        kfree(vol);
 }
 

diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 263743e7b7413644905f6ccae51c19b60d9ff88f..94d7a865b135a926501ab87e050fd3f325841488 100644 (file)
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -534,7 +534,7 @@ static int init_volumes(struct ubi_device *ubi,
                        const struct ubi_attach_info *ai,
                        const struct ubi_vtbl_record *vtbl)
 {
-       int i, reserved_pebs = 0;
+       int i, err, reserved_pebs = 0;
        struct ubi_ainf_volume *av;
        struct ubi_volume *vol;
 
@@ -620,6 +620,16 @@ static int init_volumes(struct ubi_device *ubi,
                        (long long)(vol->used_ebs - 1) * vol->usable_leb_size;
                vol->used_bytes += av->last_data_size;
                vol->last_eb_bytes = av->last_data_size;
+
+               /*
+                * We use ubi->peb_count and not vol->reserved_pebs because
+                * we want to keep the code simple. Otherwise we'd have to
+                * resize/check the bitmap upon volume resize too.
+                * Allocating a few bytes more does not hurt.
+                */
+               err = ubi_fastmap_init_checkmap(vol, ubi->peb_count);
+               if (err)
+                       return err;
        }
 
        /* And add the layout volume */
@@ -645,6 +655,9 @@ static int init_volumes(struct ubi_device *ubi,
        reserved_pebs += vol->reserved_pebs;
        ubi->vol_count += 1;
        vol->ubi = ubi;
+       err = ubi_fastmap_init_checkmap(vol, UBI_LAYOUT_VOLUME_EBS);
+       if (err)
+               return err;
 
        if (reserved_pebs > ubi->avail_pebs) {
                ubi_err(ubi, "not enough PEBs, required %d, available %d",
@@ -849,6 +862,7 @@ int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai)
 out_free:
        vfree(ubi->vtbl);
        for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
+               ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
                kfree(ubi->volumes[i]);
                ubi->volumes[i] = NULL;
        }