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path: root/drivers/mtd/ubi/build.c
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Diffstat (limited to 'drivers/mtd/ubi/build.c')
-rw-r--r--drivers/mtd/ubi/build.c161
1 files changed, 150 insertions, 11 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 4048db83aef..286ed594e5a 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -41,6 +41,7 @@
#include <linux/miscdevice.h>
#include <linux/log2.h>
#include <linux/kthread.h>
+#include <linux/reboot.h>
#include "ubi.h"
/* Maximum length of the 'mtd=' parameter */
@@ -122,6 +123,94 @@ static struct device_attribute dev_mtd_num =
__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
/**
+ * ubi_volume_notify - send a volume change notification.
+ * @ubi: UBI device description object
+ * @vol: volume description object of the changed volume
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ *
+ * This is a helper function which notifies all subscribers about a volume
+ * change event (creation, removal, re-sizing, re-naming, updating). Returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
+{
+ struct ubi_notification nt;
+
+ ubi_do_get_device_info(ubi, &nt.di);
+ ubi_do_get_volume_info(ubi, vol, &nt.vi);
+ return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
+}
+
+/**
+ * ubi_notify_all - send a notification to all volumes.
+ * @ubi: UBI device description object
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ * @nb: the notifier to call
+ *
+ * This function walks all volumes of UBI device @ubi and sends the @ntype
+ * notification for each volume. If @nb is %NULL, then all registered notifiers
+ * are called, otherwise only the @nb notifier is called. Returns the number of
+ * sent notifications.
+ */
+int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
+{
+ struct ubi_notification nt;
+ int i, count = 0;
+
+ ubi_do_get_device_info(ubi, &nt.di);
+
+ mutex_lock(&ubi->device_mutex);
+ for (i = 0; i < ubi->vtbl_slots; i++) {
+ /*
+ * Since the @ubi->device is locked, and we are not going to
+ * change @ubi->volumes, we do not have to lock
+ * @ubi->volumes_lock.
+ */
+ if (!ubi->volumes[i])
+ continue;
+
+ ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
+ if (nb)
+ nb->notifier_call(nb, ntype, &nt);
+ else
+ blocking_notifier_call_chain(&ubi_notifiers, ntype,
+ &nt);
+ count += 1;
+ }
+ mutex_unlock(&ubi->device_mutex);
+
+ return count;
+}
+
+/**
+ * ubi_enumerate_volumes - send "add" notification for all existing volumes.
+ * @nb: the notifier to call
+ *
+ * This function walks all UBI devices and volumes and sends the
+ * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
+ * registered notifiers are called, otherwise only the @nb notifier is called.
+ * Returns the number of sent notifications.
+ */
+int ubi_enumerate_volumes(struct notifier_block *nb)
+{
+ int i, count = 0;
+
+ /*
+ * Since the @ubi_devices_mutex is locked, and we are not going to
+ * change @ubi_devices, we do not have to lock @ubi_devices_lock.
+ */
+ for (i = 0; i < UBI_MAX_DEVICES; i++) {
+ struct ubi_device *ubi = ubi_devices[i];
+
+ if (!ubi)
+ continue;
+ count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
+ }
+
+ return count;
+}
+
+/**
* ubi_get_device - get UBI device.
* @ubi_num: UBI device number
*
@@ -380,7 +469,7 @@ static void free_user_volumes(struct ubi_device *ubi)
* @ubi: UBI device description object
*
* This function returns zero in case of success and a negative error code in
- * case of failure. Note, this function destroys all volumes if it failes.
+ * case of failure. Note, this function destroys all volumes if it fails.
*/
static int uif_init(struct ubi_device *ubi)
{
@@ -633,6 +722,15 @@ static int io_init(struct ubi_device *ubi)
}
/*
+ * Set maximum amount of physical erroneous eraseblocks to be 10%.
+ * Erroneous PEB are those which have read errors.
+ */
+ ubi->max_erroneous = ubi->peb_count / 10;
+ if (ubi->max_erroneous < 16)
+ ubi->max_erroneous = 16;
+ dbg_msg("max_erroneous %d", ubi->max_erroneous);
+
+ /*
* It may happen that EC and VID headers are situated in one minimal
* I/O unit. In this case we can only accept this UBI image in
* read-only mode.
@@ -726,6 +824,34 @@ static int autoresize(struct ubi_device *ubi, int vol_id)
}
/**
+ * ubi_reboot_notifier - halt UBI transactions immediately prior to a reboot.
+ * @n: reboot notifier object
+ * @state: SYS_RESTART, SYS_HALT, or SYS_POWER_OFF
+ * @cmd: pointer to command string for RESTART2
+ *
+ * This function stops the UBI background thread so that the flash device
+ * remains quiescent when Linux restarts the system. Any queued work will be
+ * discarded, but this function will block until do_work() finishes if an
+ * operation is already in progress.
+ *
+ * This function solves a real-life problem observed on NOR flashes when an
+ * PEB erase operation starts, then the system is rebooted before the erase is
+ * finishes, and the boot loader gets confused and dies. So we prefer to finish
+ * the ongoing operation before rebooting.
+ */
+static int ubi_reboot_notifier(struct notifier_block *n, unsigned long state,
+ void *cmd)
+{
+ struct ubi_device *ubi;
+
+ ubi = container_of(n, struct ubi_device, reboot_notifier);
+ if (ubi->bgt_thread)
+ kthread_stop(ubi->bgt_thread);
+ ubi_sync(ubi->ubi_num);
+ return NOTIFY_DONE;
+}
+
+/**
* ubi_attach_mtd_dev - attach an MTD device.
* @mtd: MTD device description object
* @ubi_num: number to assign to the new UBI device
@@ -806,8 +932,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
mutex_init(&ubi->buf_mutex);
mutex_init(&ubi->ckvol_mutex);
- mutex_init(&ubi->mult_mutex);
- mutex_init(&ubi->volumes_mutex);
+ mutex_init(&ubi->device_mutex);
spin_lock_init(&ubi->volumes_lock);
ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
@@ -825,7 +950,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
if (!ubi->peb_buf2)
goto out_free;
-#ifdef CONFIG_MTD_UBI_DEBUG
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
mutex_init(&ubi->dbg_buf_mutex);
ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
if (!ubi->dbg_peb_buf)
@@ -872,11 +997,23 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
ubi->beb_rsvd_pebs);
ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
+ /*
+ * The below lock makes sure we do not race with 'ubi_thread()' which
+ * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
+ */
+ spin_lock(&ubi->wl_lock);
if (!DBG_DISABLE_BGT)
ubi->thread_enabled = 1;
wake_up_process(ubi->bgt_thread);
+ spin_unlock(&ubi->wl_lock);
+
+ /* Flash device priority is 0 - UBI needs to shut down first */
+ ubi->reboot_notifier.priority = 1;
+ ubi->reboot_notifier.notifier_call = ubi_reboot_notifier;
+ register_reboot_notifier(&ubi->reboot_notifier);
ubi_devices[ubi_num] = ubi;
+ ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
return ubi_num;
out_uif:
@@ -892,7 +1029,7 @@ out_detach:
out_free:
vfree(ubi->peb_buf1);
vfree(ubi->peb_buf2);
-#ifdef CONFIG_MTD_UBI_DEBUG
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
vfree(ubi->dbg_peb_buf);
#endif
kfree(ubi);
@@ -919,13 +1056,13 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
return -EINVAL;
- spin_lock(&ubi_devices_lock);
- ubi = ubi_devices[ubi_num];
- if (!ubi) {
- spin_unlock(&ubi_devices_lock);
+ ubi = ubi_get_device(ubi_num);
+ if (!ubi)
return -EINVAL;
- }
+ spin_lock(&ubi_devices_lock);
+ put_device(&ubi->dev);
+ ubi->ref_count -= 1;
if (ubi->ref_count) {
if (!anyway) {
spin_unlock(&ubi_devices_lock);
@@ -939,12 +1076,14 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
spin_unlock(&ubi_devices_lock);
ubi_assert(ubi_num == ubi->ubi_num);
+ ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
/*
* Before freeing anything, we have to stop the background thread to
* prevent it from doing anything on this device while we are freeing.
*/
+ unregister_reboot_notifier(&ubi->reboot_notifier);
if (ubi->bgt_thread)
kthread_stop(ubi->bgt_thread);
@@ -961,7 +1100,7 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
put_mtd_device(ubi->mtd);
vfree(ubi->peb_buf1);
vfree(ubi->peb_buf2);
-#ifdef CONFIG_MTD_UBI_DEBUG
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
vfree(ubi->dbg_peb_buf);
#endif
ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);