The default value should be OK for SLC NAND flashes, NOR flashes and
other flashes which have eraseblock life-cycle 100000 or more.
However, in case of MLC NAND flashes which typically have eraseblock
- life-cycle less then 10000, the threshold should be lessened (e.g.,
+ life-cycle less than 10000, the threshold should be lessened (e.g.,
to 128 or 256, although it does not have to be power of 2).
config MTD_UBI_BEB_RESERVE
#include <linux/miscdevice.h>
#include <linux/log2.h>
#include <linux/kthread.h>
-#include <linux/reboot.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include "ubi.h"
/* Maximum length of the 'mtd=' parameter */
#define MTD_PARAM_LEN_MAX 64
+#ifdef CONFIG_MTD_UBI_MODULE
+#define ubi_is_module() 1
+#else
+#define ubi_is_module() 0
+#endif
+
/**
* struct mtd_dev_param - MTD device parameter description data structure.
* @name: MTD character device node path, MTD device name, or MTD device number
return 0;
}
-/**
- * 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
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;
* 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);
p->vid_hdr_offs);
mutex_unlock(&ubi_devices_mutex);
if (err < 0) {
- put_mtd_device(mtd);
ubi_err("cannot attach mtd%d", mtd->index);
- goto out_detach;
+ put_mtd_device(mtd);
+
+ /*
+ * Originally UBI stopped initializing on any error.
+ * However, later on it was found out that this
+ * behavior is not very good when UBI is compiled into
+ * the kernel and the MTD devices to attach are passed
+ * through the command line. Indeed, UBI failure
+ * stopped whole boot sequence.
+ *
+ * To fix this, we changed the behavior for the
+ * non-module case, but preserved the old behavior for
+ * the module case, just for compatibility. This is a
+ * little inconsistent, though.
+ */
+ if (ubi_is_module())
+ goto out_detach;
}
}
* device, e.g., make @ubi->min_io_size = 512 in the example above?
*
* A: because when writing a sub-page, MTD still writes a full 2K page but the
- * bytes which are no relevant to the sub-page are 0xFF. So, basically, writing
- * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we
- * prefer to use sub-pages only for EV and VID headers.
+ * bytes which are not relevant to the sub-page are 0xFF. So, basically,
+ * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page.
+ * Thus, we prefer to use sub-pages only for EC and VID headers.
*
* As it was noted above, the VID header may start at a non-aligned offset.
* For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
*
* This function changes the contents of a logical eraseblock atomically. @buf
* has to contain new logical eraseblock data, and @len - the length of the
- * data, which has to be aligned. The length may be shorter then the logical
+ * data, which has to be aligned. The length may be shorter than the logical
* eraseblock size, ant the logical eraseblock may be appended to more times
* later on. This function guarantees that in case of an unclean reboot the old
* contents is preserved. Returns zero in case of success and a negative error
*
* This function un-maps logical eraseblock @lnum and schedules the
* corresponding physical eraseblock for erasure, so that it will eventually be
- * physically erased in background. This operation is much faster then the
+ * physically erased in background. This operation is much faster than the
* erase operation.
*
* Unlike erase, the un-map operation does not guarantee that the logical
*
* The main and obvious use-case of this function is when the contents of a
* logical eraseblock has to be re-written. Then it is much more efficient to
- * first un-map it, then write new data, rather then first erase it, then write
+ * first un-map it, then write new data, rather than first erase it, then write
* new data. Note, once new data has been written to the logical eraseblock,
* UBI guarantees that the old contents has gone forever. In other words, if an
* unclean reboot happens after the logical eraseblock has been un-mapped and
* case of success this function returns a positive value, in case of failure, a
* negative error code is returned. The success return codes use the following
* bits:
- * o bit 0 is cleared: the first PEB (described by @seb) is newer then the
+ * o bit 0 is cleared: the first PEB (described by @seb) is newer than the
* second PEB (described by @pnum and @vid_hdr);
* o bit 0 is set: the second PEB is newer;
* o bit 1 is cleared: no bit-flips were detected in the newer LEB;
if (cmp_res & 1) {
/*
- * This logical eraseblock is newer then the one
+ * This logical eraseblock is newer than the one
* found earlier.
*/
err = validate_vid_hdr(vid_hdr, sv, pnum);
* @bgt_thread: background thread description object
* @thread_enabled: if the background thread is enabled
* @bgt_name: background thread name
- * @reboot_notifier: notifier to terminate background thread before rebooting
*
* @flash_size: underlying MTD device size (in bytes)
* @peb_count: count of physical eraseblocks on the MTD device
struct task_struct *bgt_thread;
int thread_enabled;
char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
- struct notifier_block reboot_notifier;
/* I/O sub-system's stuff */
long long flash_size;
* 0 contains more recent information.
*
* So the plan is to first check LEB 0. Then
- * a. if LEB 0 is OK, it must be containing the most resent data; then
+ * a. if LEB 0 is OK, it must be containing the most recent data; then
* we compare it with LEB 1, and if they are different, we copy LEB
* 0 to LEB 1;
* b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1
goto out_free;
/*
- * Get sure that the scanning information is consistent to the
+ * Make sure that the scanning information is consistent to the
* information stored in the volume table.
*/
err = check_scanning_info(ubi, si);
* @max: highest possible erase counter
*
* This function looks for a wear leveling entry with erase counter closest to
- * @max and less then @max.
+ * @max and less than @max.
*/
static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int max)
{
projects / firefly-linux-kernel-4.4.55.git / commitdiff