Patchwork 3/3 ubi notification API (was Re: [PATCH] [UBI] [1/3] ubi notifications API)

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Submitter dmitry pervushin
Date May 31, 2009, 2:32 p.m.
Message ID <1243780379.4067.35.camel@hp.diimka.lan>
Download mbox | patch
Permalink /patch/27892/
State New
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Comments

dmitry pervushin - May 31, 2009, 2:32 p.m.
On Sun, 2009-05-31 at 16:52 +0300, Artem Bityutskiy wrote: 
> On Fri, 2009-05-29 at 23:27 +0400, dmitry pervushin wrote:
> > > I've also created an "experimental" branch in the ubi-2.6.git
> > > tree for your convenience:
> > > 
> > > http://git.infradead.org/ubi-2.6.git?a=shortlog;h=refs/heads/experimental
> > > git://git.infradead.org/ubi-2.6.git experimental
> > Sorry for late response; I reviewed your changes, and although
> > prohibiting of using ubi api from within notifiers does not look very
> > amazing to me... but it seems that it is the only robust way. The 3rd
> > patch from the serie is inlined below (tested on the stmp378x board as
> > well as on nandsim)
> > 
> > The standalone gluebi support that uses UBI notifications.
> > 
> > Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com>
> 
> Just applied this to
> git://git.infradead.org/ubi-2.6.git experimental
> 
> and got:
> 
Oh, shame on me. I attached the patch with the same name from the wrong
directory; below is the correct one.

Signed-off-by: dmitry pervushin <dpervushin@embeddedalley.com>

---
 drivers/mtd/ubi/Kconfig  |    2 
 drivers/mtd/ubi/Makefile |    2 
 drivers/mtd/ubi/gluebi.c |  191 ++++++++++++++++++++++++++++++++++++-----------
 3 files changed, 152 insertions(+), 43 deletions(-)

Patch

Index: experimental/drivers/mtd/ubi/Kconfig
===================================================================
--- experimental.orig/drivers/mtd/ubi/Kconfig
+++ experimental/drivers/mtd/ubi/Kconfig
@@ -49,7 +49,7 @@  config MTD_UBI_BEB_RESERVE
 	  reserved. Leave the default value if unsure.
 
 config MTD_UBI_GLUEBI
-	bool "Emulate MTD devices"
+	tristate "Emulate MTD devices"
 	default n
 	depends on MTD_UBI
 	help
Index: experimental/drivers/mtd/ubi/Makefile
===================================================================
--- experimental.orig/drivers/mtd/ubi/Makefile
+++ experimental/drivers/mtd/ubi/Makefile
@@ -4,4 +4,4 @@  ubi-y += vtbl.o vmt.o upd.o build.o cdev
 ubi-y += misc.o
 
 ubi-$(CONFIG_MTD_UBI_DEBUG) += debug.o
-ubi-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o
+obj-$(CONFIG_MTD_UBI_GLUEBI) += gluebi.o
Index: experimental/drivers/mtd/ubi/gluebi.c
===================================================================
--- experimental.orig/drivers/mtd/ubi/gluebi.c
+++ experimental/drivers/mtd/ubi/gluebi.c
@@ -31,6 +31,32 @@ 
 #include <linux/math64.h>
 #include "ubi.h"
 
+struct ubi_gluebi_volume {
+	struct mtd_info gluebi_mtd;
+	int gluebi_refcount;
+	struct ubi_volume_desc *gluebi_desc;
+	int ubi_num;
+	int vol_id;
+	struct list_head list;
+};
+
+static LIST_HEAD(ubi_gluebi_mtds);
+static DEFINE_SPINLOCK(ubi_gluebi_lock);
+
+static struct ubi_gluebi_volume *ubi_gluebi_find(int ubi_num, int vol_id)
+{
+	struct ubi_gluebi_volume *pos = NULL;
+
+	spin_lock(&ubi_gluebi_lock);
+	list_for_each_entry(pos, &ubi_gluebi_mtds, list)
+		if (pos->ubi_num == ubi_num && pos->vol_id == vol_id) {
+			spin_unlock(&ubi_gluebi_lock);
+			return pos;
+		}
+	spin_unlock(&ubi_gluebi_lock);
+	return NULL;
+}
+
 /**
  * gluebi_get_device - get MTD device reference.
  * @mtd: the MTD device description object
@@ -41,9 +67,13 @@ 
  */
 static int gluebi_get_device(struct mtd_info *mtd)
 {
-	struct ubi_volume *vol;
+	struct ubi_gluebi_volume *vol;
+	int ubi_mode = UBI_READONLY;
+
+	if (mtd->flags & MTD_WRITEABLE)
+		ubi_mode = UBI_READWRITE;
 
-	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
+	vol = container_of(mtd, struct ubi_gluebi_volume, gluebi_mtd);
 
 	/*
 	 * We do not introduce locks for gluebi reference count because the
@@ -66,8 +96,7 @@  static int gluebi_get_device(struct mtd_
 	 * This is the first reference to this UBI volume via the MTD device
 	 * interface. Open the corresponding volume in read-write mode.
 	 */
-	vol->gluebi_desc = ubi_open_volume(vol->ubi->ubi_num, vol->vol_id,
-					   UBI_READWRITE);
+	vol->gluebi_desc = ubi_open_volume(vol->ubi_num, vol->vol_id, ubi_mode);
 	if (IS_ERR(vol->gluebi_desc))
 		return PTR_ERR(vol->gluebi_desc);
 	vol->gluebi_refcount += 1;
@@ -83,9 +112,9 @@  static int gluebi_get_device(struct mtd_
  */
 static void gluebi_put_device(struct mtd_info *mtd)
 {
-	struct ubi_volume *vol;
+	struct ubi_gluebi_volume *vol;
 
-	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
+	vol = container_of(mtd, struct ubi_gluebi_volume, gluebi_mtd);
 	vol->gluebi_refcount -= 1;
 	ubi_assert(vol->gluebi_refcount >= 0);
 	if (vol->gluebi_refcount == 0)
@@ -107,16 +136,14 @@  static int gluebi_read(struct mtd_info *
 		       size_t *retlen, unsigned char *buf)
 {
 	int err = 0, lnum, offs, total_read;
-	struct ubi_volume *vol;
-	struct ubi_device *ubi;
+	struct ubi_gluebi_volume *vol;
 
 	dbg_gen("read %zd bytes from offset %lld", len, from);
 
 	if (len < 0 || from < 0 || from + len > mtd->size)
 		return -EINVAL;
 
-	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
-	ubi = vol->ubi;
+	vol = container_of(mtd, struct ubi_gluebi_volume, gluebi_mtd);
 
 	lnum = div_u64_rem(from, mtd->erasesize, &offs);
 	total_read = len;
@@ -126,7 +153,7 @@  static int gluebi_read(struct mtd_info *
 		if (to_read > total_read)
 			to_read = total_read;
 
-		err = ubi_eba_read_leb(ubi, vol, lnum, buf, offs, to_read, 0);
+		err = ubi_read(vol->gluebi_desc, lnum, buf, offs, to_read);
 		if (err)
 			break;
 
@@ -152,21 +179,19 @@  static int gluebi_read(struct mtd_info *
  * case of failure.
  */
 static int gluebi_write(struct mtd_info *mtd, loff_t to, size_t len,
-		       size_t *retlen, const u_char *buf)
+			size_t *retlen, const u_char *buf)
 {
 	int err = 0, lnum, offs, total_written;
-	struct ubi_volume *vol;
-	struct ubi_device *ubi;
+	struct ubi_gluebi_volume *vol;
 
 	dbg_gen("write %zd bytes to offset %lld", len, to);
 
 	if (len < 0 || to < 0 || len + to > mtd->size)
 		return -EINVAL;
 
-	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
-	ubi = vol->ubi;
+	vol = container_of(mtd, struct ubi_gluebi_volume, gluebi_mtd);
 
-	if (ubi->ro_mode)
+	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 
 	lnum = div_u64_rem(to, mtd->erasesize, &offs);
@@ -181,8 +206,7 @@  static int gluebi_write(struct mtd_info
 		if (to_write > total_written)
 			to_write = total_written;
 
-		err = ubi_eba_write_leb(ubi, vol, lnum, buf, offs, to_write,
-					UBI_UNKNOWN);
+		err = ubi_write(vol->gluebi_desc, lnum, buf, offs, to_write);
 		if (err)
 			break;
 
@@ -207,8 +231,7 @@  static int gluebi_write(struct mtd_info
 static int gluebi_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
 	int err, i, lnum, count;
-	struct ubi_volume *vol;
-	struct ubi_device *ubi;
+	struct ubi_gluebi_volume *vol;
 
 	dbg_gen("erase %llu bytes at offset %llu", (unsigned long long)instr->len,
 		 (unsigned long long)instr->addr);
@@ -225,23 +248,24 @@  static int gluebi_erase(struct mtd_info
 	lnum = mtd_div_by_eb(instr->addr, mtd);
 	count = mtd_div_by_eb(instr->len, mtd);
 
-	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
-	ubi = vol->ubi;
+	vol = container_of(mtd, struct ubi_gluebi_volume, gluebi_mtd);
 
-	if (ubi->ro_mode)
+	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 
-	for (i = 0; i < count; i++) {
-		err = ubi_eba_unmap_leb(ubi, vol, lnum + i);
+	for (i = 0; i < count - 1; i++) {
+		err = ubi_leb_unmap(vol->gluebi_desc, lnum + i);
 		if (err)
 			goto out_err;
 	}
-
 	/*
 	 * MTD erase operations are synchronous, so we have to make sure the
 	 * physical eraseblock is wiped out.
+	 *
+	 * Thus, perform leb_erase instead of leb_unmap operation - leb_erase
+	 * will wait for the end of operations
 	 */
-	err = ubi_wl_flush(ubi);
+	err = ubi_leb_erase(vol->gluebi_desc, lnum + i);
 	if (err)
 		goto out_err;
 
@@ -264,13 +288,28 @@  out_err:
  * corresponding fake MTD device. Returns zero in case of success and a
  * negative error code in case of failure.
  */
-int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol)
+static int ubi_create_gluebi(struct ubi_device_info *ubi,
+			     struct ubi_volume_info *vol)
 {
-	struct mtd_info *mtd = &vol->gluebi_mtd;
+	struct ubi_gluebi_volume *v;
+	struct mtd_info *mtd;
+
+	v = kzalloc(sizeof(*v), GFP_KERNEL);
+	if (!v) {
+		ubi_err("Cannot allocate ubi_gluebi_vol");
+		return -ENOMEM;
+	}
+
+	mtd = &v->gluebi_mtd;
 
 	mtd->name = kmemdup(vol->name, vol->name_len + 1, GFP_KERNEL);
-	if (!mtd->name)
+	if (!mtd->name) {
+		ubi_err("Cannot allocate mtd->name");
+		kfree(v);
 		return -ENOMEM;
+	}
+
+	v->vol_id = vol->vol_id;
 
 	mtd->type = MTD_UBIVOLUME;
 	if (!ubi->ro_mode)
@@ -290,16 +329,21 @@  int ubi_create_gluebi(struct ubi_device
 	 * bytes.
 	 */
 	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
-		mtd->size = (long long)vol->usable_leb_size * vol->reserved_pebs;
+		mtd->size = (long long)vol->usable_leb_size * vol->size;
 	else
 		mtd->size = vol->used_bytes;
 
 	if (add_mtd_device(mtd)) {
-		ubi_err("cannot not add MTD device");
+		ubi_err("cannot add MTD device");
 		kfree(mtd->name);
+		kfree(v);
 		return -ENFILE;
 	}
 
+	spin_lock(&ubi_gluebi_lock);
+	list_add_tail(&v->list, &ubi_gluebi_mtds);
+	spin_unlock(&ubi_gluebi_lock);
+
 	dbg_gen("added mtd%d (\"%s\"), size %llu, EB size %u",
 		mtd->index, mtd->name, (unsigned long long)mtd->size, mtd->erasesize);
 	return 0;
@@ -307,38 +351,103 @@  int ubi_create_gluebi(struct ubi_device
 
 /**
  * ubi_destroy_gluebi - close gluebi for an UBI volume.
- * @vol: volume description object
+ * @vi: volume info structure
  *
  * This function is called when an UBI volume is removed in order to remove
  * corresponding fake MTD device. Returns zero in case of success and a
  * negative error code in case of failure.
  */
-int ubi_destroy_gluebi(struct ubi_volume *vol)
+static int ubi_destroy_gluebi(struct ubi_volume_info *vi)
 {
 	int err;
-	struct mtd_info *mtd = &vol->gluebi_mtd;
+	struct ubi_gluebi_volume *gluebi_vol;
+	struct mtd_info *mtd;
+
+	gluebi_vol = ubi_gluebi_find(vi->ubi_num, vi->vol_id);
+	if (!gluebi_vol)
+		return -ENOENT;
 
+	mtd = &gluebi_vol->gluebi_mtd;
 	dbg_gen("remove mtd%d", mtd->index);
 	err = del_mtd_device(mtd);
 	if (err)
 		return err;
 	kfree(mtd->name);
+
+	spin_lock(&ubi_gluebi_lock);
+	list_del(&gluebi_vol->list);
+	spin_unlock(&ubi_gluebi_lock);
+
+	kfree(gluebi_vol);
 	return 0;
 }
 
 /**
  * ubi_gluebi_updated - UBI volume was updated notifier.
- * @vol: volume description object
+ * @vi: volume info structure
  *
  * This function is called every time an UBI volume is updated. This function
  * does nothing if volume @vol is dynamic, and changes MTD device size if the
  * volume is static. This is needed because static volumes cannot be read past
  * data they contain.
  */
-void ubi_gluebi_updated(struct ubi_volume *vol)
+static void ubi_gluebi_updated(struct ubi_volume_info *vi)
 {
-	struct mtd_info *mtd = &vol->gluebi_mtd;
+	struct ubi_gluebi_volume *gluebi_vol;
 
-	if (vol->vol_type == UBI_STATIC_VOLUME)
-		mtd->size = vol->used_bytes;
+	gluebi_vol = ubi_gluebi_find(vi->ubi_num, vi->vol_id);
+	if (!gluebi_vol)
+		return /* -ENOENT */;
+
+	if (vi->vol_type == UBI_STATIC_VOLUME)
+		gluebi_vol->gluebi_mtd.size = vi->used_bytes;
+}
+
+/**
+ * ubi_gluebi_notify - notification handler.
+ * @nb: the registered notifier_block
+ * @l: notification type
+ * @ns_ptr: pointer to the &struct ubi_volume_notification
+ */
+static int ubi_gluebi_notify(struct notifier_block *nb,
+			     unsigned long l, void *ns_ptr)
+{
+	struct ubi_notification *ns = ns_ptr;
+
+	switch (l) {
+	case UBI_VOLUME_ADDED:
+		ubi_create_gluebi(&ns->di, &ns->vi);
+		break;
+	case UBI_VOLUME_REMOVED:
+		ubi_destroy_gluebi(&ns->vi);
+		break;
+	case UBI_VOLUME_RESIZED:
+		ubi_gluebi_updated(&ns->vi);
+		break;
+	case UBI_VOLUME_RENAMED:
+	case UBI_VOLUME_UPDATED:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block ubi_gluebi_notifier = {
+	.notifier_call	= ubi_gluebi_notify,
+};
+
+static int __init ubi_gluebi_init(void)
+{
+	spin_lock_init(&ubi_gluebi_lock);
+	return ubi_register_volume_notifier(&ubi_gluebi_notifier, false);
 }
+
+static void __exit ubi_gluebi_exit(void)
+{
+	ubi_unregister_volume_notifier(&ubi_gluebi_notifier);
+}
+
+module_init(ubi_gluebi_init);
+module_exit(ubi_gluebi_exit);
+MODULE_DESCRIPTION("MTD emulation layer over UBI volumes");
+MODULE_AUTHOR("Artem Bityutskiy, Joern Engel");
+MODULE_LICENSE("GPL");