[PATCHv3 0/9] mtd: Remove static limit on device numbers

[PATCHv3 0/9] mtd: Remove static limit on device numbers

[Ben Hutchings]

This is the third version of this patch series.  Please give me some
feedback, David?

Changes since v2:
- Export idr_get_next() to support building mtdcore as a module
- Correct the limit on block device numbers in mtd_blkdevs
- Register the full range of minor numbers in mtdchar

Ben.

Ben Hutchings (9):
  mtd: Introduce and use iteration macro for reading the MTD device
    table
  mtd: Use get_mtd_device_nm() to find named device in get_sb_mtd()
  nandsim: Define CONFIG_NANDSIM_MAX_PARTS and use it instead of
    MAX_MTD_DEVICES
  mtd: Remove unnecessary comparisons with MAX_MTD_DEVICES
  mtdblock: Dynamically allocate cache info structures
  idr: Export idr_get_next()
  mtd: Replace static array of devices with an idr structure
  mtd: Raise limit on block device minor numbers
  mtdchar: Register the full range of minor numbers

 drivers/mtd/devices/pmc551.c |    4 +-
 drivers/mtd/mtd_blkdevs.c    |   17 ++--
 drivers/mtd/mtdblock.c       |   74 +++++++---------
 drivers/mtd/mtdchar.c        |    8 +-
 drivers/mtd/mtdcore.c        |  205 +++++++++++++++++++++--------------------
 drivers/mtd/mtdcore.h        |    7 ++-
 drivers/mtd/mtdoops.c        |    5 -
 drivers/mtd/mtdsuper.c       |   18 ++---
 drivers/mtd/nand/nandsim.c   |    7 +-
 include/linux/mtd/mtd.h      |    1 -
 lib/idr.c                    |    2 +-
 11 files changed, 169 insertions(+), 179 deletions(-)

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 1/9] mtd: Introduce and use iteration macro for reading the MTD device table

[Ben Hutchings]

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/mtd_blkdevs.c |   10 ++++----
 drivers/mtd/mtdcore.c     |   54 ++++++++++++++++++++------------------------
 drivers/mtd/mtdcore.h     |   15 ++++++++++++
 3 files changed, 45 insertions(+), 34 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index c82e09b..85a52b3 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -335,7 +335,8 @@ static struct mtd_notifier blktrans_notifier = {
 
 int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 {
-	int ret, i;
+	struct mtd_info *mtd;
+	int ret;
 
 	/* Register the notifier if/when the first device type is
 	   registered, to prevent the link/init ordering from fucking
@@ -389,10 +390,9 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 	INIT_LIST_HEAD(&tr->devs);
 	list_add(&tr->list, &blktrans_majors);
 
-	for (i=0; i<MAX_MTD_DEVICES; i++) {
-		if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT)
-			tr->add_mtd(tr, mtd_table[i]);
-	}
+	mtd_for_each_device(mtd)
+		if (mtd->type != MTD_ABSENT)
+			tr->add_mtd(tr, mtd);
 
 	mutex_unlock(&mtd_table_mutex);
 
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index c356c0a..402d417 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -381,7 +381,7 @@ int del_mtd_device (struct mtd_info *mtd)
 
 void register_mtd_user (struct mtd_notifier *new)
 {
-	int i;
+	struct mtd_info *mtd;
 
 	mutex_lock(&mtd_table_mutex);
 
@@ -389,9 +389,8 @@ void register_mtd_user (struct mtd_notifier *new)
 
  	__module_get(THIS_MODULE);
 
-	for (i=0; i< MAX_MTD_DEVICES; i++)
-		if (mtd_table[i])
-			new->add(mtd_table[i]);
+	mtd_for_each_device(mtd)
+		new->add(mtd);
 
 	mutex_unlock(&mtd_table_mutex);
 }
@@ -408,15 +407,14 @@ void register_mtd_user (struct mtd_notifier *new)
 
 int unregister_mtd_user (struct mtd_notifier *old)
 {
-	int i;
+	struct mtd_info *mtd;
 
 	mutex_lock(&mtd_table_mutex);
 
 	module_put(THIS_MODULE);
 
-	for (i=0; i< MAX_MTD_DEVICES; i++)
-		if (mtd_table[i])
-			old->remove(mtd_table[i]);
+	mtd_for_each_device(mtd)
+		old->remove(mtd);
 
 	list_del(&old->list);
 	mutex_unlock(&mtd_table_mutex);
@@ -438,15 +436,18 @@ int unregister_mtd_user (struct mtd_notifier *old)
 
 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
 {
-	struct mtd_info *ret = NULL;
-	int i, err = -ENODEV;
+	struct mtd_info *ret = NULL, *other;
+	int err = -ENODEV;
 
 	mutex_lock(&mtd_table_mutex);
 
 	if (num == -1) {
-		for (i=0; i< MAX_MTD_DEVICES; i++)
-			if (mtd_table[i] == mtd)
-				ret = mtd_table[i];
+		mtd_for_each_device(other) {
+			if (other == mtd) {
+				ret = mtd;
+				break;
+			}
+		}
 	} else if (num >= 0 && num < MAX_MTD_DEVICES) {
 		ret = mtd_table[num];
 		if (mtd && mtd != ret)
@@ -487,14 +488,14 @@ out_unlock:
 
 struct mtd_info *get_mtd_device_nm(const char *name)
 {
-	int i, err = -ENODEV;
-	struct mtd_info *mtd = NULL;
+	int err = -ENODEV;
+	struct mtd_info *mtd = NULL, *other;
 
 	mutex_lock(&mtd_table_mutex);
 
-	for (i = 0; i < MAX_MTD_DEVICES; i++) {
-		if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
-			mtd = mtd_table[i];
+	mtd_for_each_device(other) {
+		if (!strcmp(name, other->name)) {
+			mtd = other;
 			break;
 		}
 	}
@@ -581,14 +582,9 @@ EXPORT_SYMBOL_GPL(default_mtd_writev);
 
 static struct proc_dir_entry *proc_mtd;
 
-static inline int mtd_proc_info (char *buf, int i)
+static inline int mtd_proc_info(char *buf, struct mtd_info *this)
 {
-	struct mtd_info *this = mtd_table[i];
-
-	if (!this)
-		return 0;
-
-	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", i,
+	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", this->index,
 		       (unsigned long long)this->size,
 		       this->erasesize, this->name);
 }
@@ -596,15 +592,15 @@ static inline int mtd_proc_info (char *buf, int i)
 static int mtd_read_proc (char *page, char **start, off_t off, int count,
 			  int *eof, void *data_unused)
 {
-	int len, l, i;
+	struct mtd_info *mtd;
+	int len, l;
         off_t   begin = 0;
 
 	mutex_lock(&mtd_table_mutex);
 
 	len = sprintf(page, "dev:    size   erasesize  name\n");
-        for (i=0; i< MAX_MTD_DEVICES; i++) {
-
-                l = mtd_proc_info(page + len, i);
+	mtd_for_each_device(mtd) {
+		l = mtd_proc_info(page + len, mtd);
                 len += l;
                 if (len+begin > off+count)
                         goto done;
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index a33251f..e2f93a3 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -9,3 +9,18 @@
 
 extern struct mutex mtd_table_mutex;
 extern struct mtd_info *mtd_table[MAX_MTD_DEVICES];
+
+static inline struct mtd_info *__mtd_next_device(int i)
+{
+	while (i < MAX_MTD_DEVICES) {
+		if (mtd_table[i])
+			return mtd_table[i];
+		i++;
+	}
+	return NULL;
+}
+
+#define mtd_for_each_device(mtd)			\
+	for ((mtd) = __mtd_next_device(0);		\
+	     (mtd) != NULL;				\
+	     (mtd) = __mtd_next_device(mtd->index + 1))
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 2/9] mtd: Use get_mtd_device_nm() to find named device in get_sb_mtd()

[Ben Hutchings]

This removes the need to know the number of MTD devices.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/mtdsuper.c |   18 ++++++------------
 1 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index af8b42e..d257052 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -150,18 +150,12 @@ int get_sb_mtd(struct file_system_type *fs_type, int flags,
 			DEBUG(1, "MTDSB: mtd:%%s, name \"%s\"\n",
 			      dev_name + 4);
 
-			for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
-				mtd = get_mtd_device(NULL, mtdnr);
-				if (!IS_ERR(mtd)) {
-					if (!strcmp(mtd->name, dev_name + 4))
-						return get_sb_mtd_aux(
-							fs_type, flags,
-							dev_name, data, mtd,
-							fill_super, mnt);
-
-					put_mtd_device(mtd);
-				}
-			}
+			mtd = get_mtd_device_nm(dev_name + 4);
+			if (!IS_ERR(mtd))
+				return get_sb_mtd_aux(
+					fs_type, flags,
+					dev_name, data, mtd,
+					fill_super, mnt);
 
 			printk(KERN_NOTICE "MTD:"
 			       " MTD device with name \"%s\" not found.\n",
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 3/9] nandsim: Define CONFIG_NANDSIM_MAX_PARTS and use it instead of MAX_MTD_DEVICES

[Ben Hutchings]

MAX_MTD_DEVICES is about to be removed.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
This shouldn't really be named CONFIG_anything, but it is consistent
with the other compile-time settings in this driver.

Ben.

 drivers/mtd/nand/nandsim.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 7281000..58c255e 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -80,6 +80,9 @@
 #ifndef CONFIG_NANDSIM_DBG
 #define CONFIG_NANDSIM_DBG        0
 #endif
+#ifndef CONFIG_NANDSIM_MAX_PARTS
+#define CONFIG_NANDSIM_MAX_PARTS  32
+#endif
 
 static uint first_id_byte  = CONFIG_NANDSIM_FIRST_ID_BYTE;
 static uint second_id_byte = CONFIG_NANDSIM_SECOND_ID_BYTE;
@@ -94,7 +97,7 @@ static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
 static uint log            = CONFIG_NANDSIM_LOG;
 static uint dbg            = CONFIG_NANDSIM_DBG;
-static unsigned long parts[MAX_MTD_DEVICES];
+static unsigned long parts[CONFIG_NANDSIM_MAX_PARTS];
 static unsigned int parts_num;
 static char *badblocks = NULL;
 static char *weakblocks = NULL;
@@ -288,7 +291,7 @@ union ns_mem {
  * The structure which describes all the internal simulator data.
  */
 struct nandsim {
-	struct mtd_partition partitions[MAX_MTD_DEVICES];
+	struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
 	unsigned int nbparts;
 
 	uint busw;              /* flash chip bus width (8 or 16) */
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 4/9] mtd: Remove unnecessary comparisons with MAX_MTD_DEVICES

[Ben Hutchings]

MAX_MTD_DEVICES is about to be removed.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/devices/pmc551.c |    4 ++--
 drivers/mtd/mtdchar.c        |    3 ---
 drivers/mtd/mtdoops.c        |    5 -----
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/devices/pmc551.c b/drivers/mtd/devices/pmc551.c
index d2fd550..fc8ea0a 100644
--- a/drivers/mtd/devices/pmc551.c
+++ b/drivers/mtd/devices/pmc551.c
@@ -668,7 +668,7 @@ static int __init init_pmc551(void)
 {
 	struct pci_dev *PCI_Device = NULL;
 	struct mypriv *priv;
-	int count, found = 0;
+	int found = 0;
 	struct mtd_info *mtd;
 	u32 length = 0;
 
@@ -695,7 +695,7 @@ static int __init init_pmc551(void)
 	/*
 	 * PCU-bus chipset probe.
 	 */
-	for (count = 0; count < MAX_MTD_DEVICES; count++) {
+	for (;;) {
 
 		if ((PCI_Device = pci_get_device(PCI_VENDOR_ID_V3_SEMI,
 						  PCI_DEVICE_ID_V3_SEMI_V370PDC,
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 5b081cb..04fd7e5 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -67,9 +67,6 @@ static int mtd_open(struct inode *inode, struct file *file)
 
 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 
-	if (devnum >= MAX_MTD_DEVICES)
-		return -ENODEV;
-
 	/* You can't open the RO devices RW */
 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
 		return -EACCES;
diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c
index 92e12df..328313c 100644
--- a/drivers/mtd/mtdoops.c
+++ b/drivers/mtd/mtdoops.c
@@ -429,11 +429,6 @@ static int __init mtdoops_init(void)
 	mtd_index = simple_strtoul(mtddev, &endp, 0);
 	if (*endp == '\0')
 		cxt->mtd_index = mtd_index;
-	if (cxt->mtd_index > MAX_MTD_DEVICES) {
-		printk(KERN_ERR "mtdoops: invalid mtd device number (%u) given\n",
-				mtd_index);
-		return -EINVAL;
-	}
 
 	cxt->oops_buf = vmalloc(record_size);
 	if (!cxt->oops_buf) {
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 5/9] mtdblock: Dynamically allocate cache info structures

[Ben Hutchings]

Since we allocate struct mtd_blktrans_dev for each block device, we
can add our own structure members to the end.  Therefore embed
struct mtd_blktrans_dev in struct mtdblk_dev and remove the static
array of struct mtdblk_dev.  Also remove the redundant pointer to
struct mtd_info.

This is preparation for removing the static limit on the number of MTD
devices.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/mtdblock.c |   74 ++++++++++++++++++++----------------------------
 1 files changed, 31 insertions(+), 43 deletions(-)

diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
index 9f41b1a..69f6bf2 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -19,15 +19,15 @@
 #include <linux/mutex.h>
 

-static struct mtdblk_dev {
-	struct mtd_info *mtd;
+struct mtdblk_dev {
+	struct mtd_blktrans_dev mbd;
 	int count;
 	struct mutex cache_mutex;
 	unsigned char *cache_data;
 	unsigned long cache_offset;
 	unsigned int cache_size;
 	enum { STATE_EMPTY, STATE_CLEAN, STATE_DIRTY } cache_state;
-} *mtdblks[MAX_MTD_DEVICES];
+};
 
 static struct mutex mtdblks_lock;
 
@@ -98,7 +98,7 @@ static int erase_write (struct mtd_info *mtd, unsigned long pos,
 
 static int write_cached_data (struct mtdblk_dev *mtdblk)
 {
-	struct mtd_info *mtd = mtdblk->mtd;
+	struct mtd_info *mtd = mtdblk->mbd.mtd;
 	int ret;
 
 	if (mtdblk->cache_state != STATE_DIRTY)
@@ -128,7 +128,7 @@ static int write_cached_data (struct mtdblk_dev *mtdblk)
 static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
 			    int len, const char *buf)
 {
-	struct mtd_info *mtd = mtdblk->mtd;
+	struct mtd_info *mtd = mtdblk->mbd.mtd;
 	unsigned int sect_size = mtdblk->cache_size;
 	size_t retlen;
 	int ret;
@@ -198,7 +198,7 @@ static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos,
 static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
 			   int len, char *buf)
 {
-	struct mtd_info *mtd = mtdblk->mtd;
+	struct mtd_info *mtd = mtdblk->mbd.mtd;
 	unsigned int sect_size = mtdblk->cache_size;
 	size_t retlen;
 	int ret;
@@ -244,16 +244,16 @@ static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos,
 static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
 			      unsigned long block, char *buf)
 {
-	struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+	struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
 	return do_cached_read(mtdblk, block<<9, 512, buf);
 }
 
 static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
 			      unsigned long block, char *buf)
 {
-	struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+	struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
 	if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) {
-		mtdblk->cache_data = vmalloc(mtdblk->mtd->erasesize);
+		mtdblk->cache_data = vmalloc(mtdblk->mbd.mtd->erasesize);
 		if (!mtdblk->cache_data)
 			return -EINTR;
 		/* -EINTR is not really correct, but it is the best match
@@ -266,37 +266,26 @@ static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
 
 static int mtdblock_open(struct mtd_blktrans_dev *mbd)
 {
-	struct mtdblk_dev *mtdblk;
-	struct mtd_info *mtd = mbd->mtd;
-	int dev = mbd->devnum;
+	struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
 
 	DEBUG(MTD_DEBUG_LEVEL1,"mtdblock_open\n");
 
 	mutex_lock(&mtdblks_lock);
-	if (mtdblks[dev]) {
-		mtdblks[dev]->count++;
+	if (mtdblk->count) {
+		mtdblk->count++;
 		mutex_unlock(&mtdblks_lock);
 		return 0;
 	}
 
 	/* OK, it's not open. Create cache info for it */
-	mtdblk = kzalloc(sizeof(struct mtdblk_dev), GFP_KERNEL);
-	if (!mtdblk) {
-		mutex_unlock(&mtdblks_lock);
-		return -ENOMEM;
-	}
-
 	mtdblk->count = 1;
-	mtdblk->mtd = mtd;
-
 	mutex_init(&mtdblk->cache_mutex);
 	mtdblk->cache_state = STATE_EMPTY;
-	if ( !(mtdblk->mtd->flags & MTD_NO_ERASE) && mtdblk->mtd->erasesize) {
-		mtdblk->cache_size = mtdblk->mtd->erasesize;
+	if (!(mbd->mtd->flags & MTD_NO_ERASE) && mbd->mtd->erasesize) {
+		mtdblk->cache_size = mbd->mtd->erasesize;
 		mtdblk->cache_data = NULL;
 	}
 
-	mtdblks[dev] = mtdblk;
 	mutex_unlock(&mtdblks_lock);
 
 	DEBUG(MTD_DEBUG_LEVEL1, "ok\n");
@@ -306,8 +295,7 @@ static int mtdblock_open(struct mtd_blktrans_dev *mbd)
 
 static int mtdblock_release(struct mtd_blktrans_dev *mbd)
 {
-	int dev = mbd->devnum;
-	struct mtdblk_dev *mtdblk = mtdblks[dev];
+	struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
 
    	DEBUG(MTD_DEBUG_LEVEL1, "mtdblock_release\n");
 
@@ -318,12 +306,10 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd)
 	mutex_unlock(&mtdblk->cache_mutex);
 
 	if (!--mtdblk->count) {
-		/* It was the last usage. Free the device */
-		mtdblks[dev] = NULL;
-		if (mtdblk->mtd->sync)
-			mtdblk->mtd->sync(mtdblk->mtd);
+		/* It was the last usage. Free the cache */
+		if (mbd->mtd->sync)
+			mbd->mtd->sync(mbd->mtd);
 		vfree(mtdblk->cache_data);
-		kfree(mtdblk);
 	}
 
 	mutex_unlock(&mtdblks_lock);
@@ -335,40 +321,42 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd)
 
 static int mtdblock_flush(struct mtd_blktrans_dev *dev)
 {
-	struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
+	struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
 
 	mutex_lock(&mtdblk->cache_mutex);
 	write_cached_data(mtdblk);
 	mutex_unlock(&mtdblk->cache_mutex);
 
-	if (mtdblk->mtd->sync)
-		mtdblk->mtd->sync(mtdblk->mtd);
+	if (dev->mtd->sync)
+		dev->mtd->sync(dev->mtd);
 	return 0;
 }
 
 static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
 {
-	struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	struct mtdblk_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 
 	if (!dev)
 		return;
 
-	dev->mtd = mtd;
-	dev->devnum = mtd->index;
+	dev->mbd.mtd = mtd;
+	dev->mbd.devnum = mtd->index;
 
-	dev->size = mtd->size >> 9;
-	dev->tr = tr;
+	dev->mbd.size = mtd->size >> 9;
+	dev->mbd.tr = tr;
 
 	if (!(mtd->flags & MTD_WRITEABLE))
-		dev->readonly = 1;
+		dev->mbd.readonly = 1;
 
-	add_mtd_blktrans_dev(dev);
+	add_mtd_blktrans_dev(&dev->mbd);
 }
 
 static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
 {
+	struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd);
+
 	del_mtd_blktrans_dev(dev);
-	kfree(dev);
+	kfree(mtdblk);
 }
 
 static struct mtd_blktrans_ops mtdblock_tr = {
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 6/9] idr: Export idr_get_next()

[Ben Hutchings]

idr_get_next() was accidentally not exported when added.  It is about
to be used by mtdcore, which may be built as a module.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 lib/idr.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/lib/idr.c b/lib/idr.c
index 1cac726..21f9266 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -621,7 +621,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
 	}
 	return NULL;
 }
-
+EXPORT_SYMBOL(idr_get_next);
 

 /**
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 7/9] mtd: Replace static array of devices with an idr structure

[Ben Hutchings]

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/mtdcore.c   |  151 +++++++++++++++++++++++++----------------------
 drivers/mtd/mtdcore.h   |   12 +----
 include/linux/mtd/mtd.h |    1 -
 3 files changed, 81 insertions(+), 83 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 402d417..b3b98d1 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/mtd/compatmac.h>
 #include <linux/proc_fs.h>
+#include <linux/idr.h>
 
 #include <linux/mtd/mtd.h>
 #include "internal.h"
@@ -33,13 +34,18 @@ static struct class mtd_class = {
 	.resume = mtd_cls_resume,
 };
 
+static DEFINE_IDR(mtd_idr);
+
 /* These are exported solely for the purpose of mtd_blkdevs.c. You
    should not use them for _anything_ else */
 DEFINE_MUTEX(mtd_table_mutex);
-struct mtd_info *mtd_table[MAX_MTD_DEVICES];
-
 EXPORT_SYMBOL_GPL(mtd_table_mutex);
-EXPORT_SYMBOL_GPL(mtd_table);
+
+struct mtd_info *__mtd_next_device(int i)
+{
+	return idr_get_next(&mtd_idr, &i);
+}
+EXPORT_SYMBOL_GPL(__mtd_next_device);
 
 static LIST_HEAD(mtd_notifiers);
 
@@ -235,13 +241,13 @@ static struct device_type mtd_devtype = {
  *	Add a device to the list of MTD devices present in the system, and
  *	notify each currently active MTD 'user' of its arrival. Returns
  *	zero on success or 1 on failure, which currently will only happen
- *	if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
- *	or there's a sysfs error.
+ *	if there is insufficient memory or a sysfs error.
  */
 
 int add_mtd_device(struct mtd_info *mtd)
 {
-	int i;
+	struct mtd_notifier *not;
+	int i, error;
 
 	if (!mtd->backing_dev_info) {
 		switch (mtd->type) {
@@ -260,70 +266,73 @@ int add_mtd_device(struct mtd_info *mtd)
 	BUG_ON(mtd->writesize == 0);
 	mutex_lock(&mtd_table_mutex);
 
-	for (i=0; i < MAX_MTD_DEVICES; i++)
-		if (!mtd_table[i]) {
-			struct mtd_notifier *not;
-
-			mtd_table[i] = mtd;
-			mtd->index = i;
-			mtd->usecount = 0;
-
-			if (is_power_of_2(mtd->erasesize))
-				mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
-			else
-				mtd->erasesize_shift = 0;
-
-			if (is_power_of_2(mtd->writesize))
-				mtd->writesize_shift = ffs(mtd->writesize) - 1;
-			else
-				mtd->writesize_shift = 0;
-
-			mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
-			mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
-
-			/* Some chips always power up locked. Unlock them now */
-			if ((mtd->flags & MTD_WRITEABLE)
-			    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
-				if (mtd->unlock(mtd, 0, mtd->size))
-					printk(KERN_WARNING
-					       "%s: unlock failed, "
-					       "writes may not work\n",
-					       mtd->name);
-			}
+	do {
+		if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
+			goto fail_locked;
+		error = idr_get_new(&mtd_idr, mtd, &i);
+	} while (error == -EAGAIN);
 
-			/* Caller should have set dev.parent to match the
-			 * physical device.
-			 */
-			mtd->dev.type = &mtd_devtype;
-			mtd->dev.class = &mtd_class;
-			mtd->dev.devt = MTD_DEVT(i);
-			dev_set_name(&mtd->dev, "mtd%d", i);
-			dev_set_drvdata(&mtd->dev, mtd);
-			if (device_register(&mtd->dev) != 0) {
-				mtd_table[i] = NULL;
-				break;
-			}
+	if (error)
+		goto fail_locked;
 
-			if (MTD_DEVT(i))
-				device_create(&mtd_class, mtd->dev.parent,
-						MTD_DEVT(i) + 1,
-						NULL, "mtd%dro", i);
-
-			DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
-			/* No need to get a refcount on the module containing
-			   the notifier, since we hold the mtd_table_mutex */
-			list_for_each_entry(not, &mtd_notifiers, list)
-				not->add(mtd);
-
-			mutex_unlock(&mtd_table_mutex);
-			/* We _know_ we aren't being removed, because
-			   our caller is still holding us here. So none
-			   of this try_ nonsense, and no bitching about it
-			   either. :) */
-			__module_get(THIS_MODULE);
-			return 0;
-		}
+	mtd->index = i;
+	mtd->usecount = 0;
+
+	if (is_power_of_2(mtd->erasesize))
+		mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
+	else
+		mtd->erasesize_shift = 0;
+
+	if (is_power_of_2(mtd->writesize))
+		mtd->writesize_shift = ffs(mtd->writesize) - 1;
+	else
+		mtd->writesize_shift = 0;
+
+	mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
+	mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
+
+	/* Some chips always power up locked. Unlock them now */
+	if ((mtd->flags & MTD_WRITEABLE)
+	    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
+		if (mtd->unlock(mtd, 0, mtd->size))
+			printk(KERN_WARNING
+			       "%s: unlock failed, writes may not work\n",
+			       mtd->name);
+	}
+
+	/* Caller should have set dev.parent to match the
+	 * physical device.
+	 */
+	mtd->dev.type = &mtd_devtype;
+	mtd->dev.class = &mtd_class;
+	mtd->dev.devt = MTD_DEVT(i);
+	dev_set_name(&mtd->dev, "mtd%d", i);
+	dev_set_drvdata(&mtd->dev, mtd);
+	if (device_register(&mtd->dev) != 0)
+		goto fail_added;
+
+	if (MTD_DEVT(i))
+		device_create(&mtd_class, mtd->dev.parent,
+			      MTD_DEVT(i) + 1,
+			      NULL, "mtd%dro", i);
+
+	DEBUG(0, "mtd: Giving out device %d to %s\n", i, mtd->name);
+	/* No need to get a refcount on the module containing
+	   the notifier, since we hold the mtd_table_mutex */
+	list_for_each_entry(not, &mtd_notifiers, list)
+		not->add(mtd);
+
+	mutex_unlock(&mtd_table_mutex);
+	/* We _know_ we aren't being removed, because
+	   our caller is still holding us here. So none
+	   of this try_ nonsense, and no bitching about it
+	   either. :) */
+	__module_get(THIS_MODULE);
+	return 0;
 
+fail_added:
+	idr_remove(&mtd_idr, i);
+fail_locked:
 	mutex_unlock(&mtd_table_mutex);
 	return 1;
 }
@@ -344,7 +353,7 @@ int del_mtd_device (struct mtd_info *mtd)
 
 	mutex_lock(&mtd_table_mutex);
 
-	if (mtd_table[mtd->index] != mtd) {
+	if (idr_find(&mtd_idr, mtd->index) != mtd) {
 		ret = -ENODEV;
 	} else if (mtd->usecount) {
 		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
@@ -360,7 +369,7 @@ int del_mtd_device (struct mtd_info *mtd)
 		list_for_each_entry(not, &mtd_notifiers, list)
 			not->remove(mtd);
 
-		mtd_table[mtd->index] = NULL;
+		idr_remove(&mtd_idr, mtd->index);
 
 		module_put(THIS_MODULE);
 		ret = 0;
@@ -448,8 +457,8 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
 				break;
 			}
 		}
-	} else if (num >= 0 && num < MAX_MTD_DEVICES) {
-		ret = mtd_table[num];
+	} else if (num >= 0) {
+		ret = idr_find(&mtd_idr, num);
 		if (mtd && mtd != ret)
 			ret = NULL;
 	}
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index e2f93a3..6a64fde 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -8,17 +8,7 @@
    should not use them for _anything_ else */
 
 extern struct mutex mtd_table_mutex;
-extern struct mtd_info *mtd_table[MAX_MTD_DEVICES];
-
-static inline struct mtd_info *__mtd_next_device(int i)
-{
-	while (i < MAX_MTD_DEVICES) {
-		if (mtd_table[i])
-			return mtd_table[i];
-		i++;
-	}
-	return NULL;
-}
+extern struct mtd_info *__mtd_next_device(int i);
 
 #define mtd_for_each_device(mtd)			\
 	for ((mtd) = __mtd_next_device(0);		\
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 0f32a9b..ba53ecc 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -20,7 +20,6 @@
 
 #define MTD_CHAR_MAJOR 90
 #define MTD_BLOCK_MAJOR 31
-#define MAX_MTD_DEVICES 32
 
 #define MTD_ERASE_PENDING      	0x01
 #define MTD_ERASING		0x02
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 8/9] mtd: Raise limit on block device minor numbers

[Ben Hutchings]

add_mtd_blktrans_dev() imposes a maximum of 257 devices per block
translator.  This was presumably meant to prevent overflow back in the
days of 8-bit minor numbers.  Instead, check against MINORMASK and the
limits of the partition naming scheme.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/mtd_blkdevs.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 85a52b3..2f8c202 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -242,9 +242,12 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	if (new->devnum == -1)
 		new->devnum = last_devnum+1;
 
-	if ((new->devnum << tr->part_bits) > 256) {
+	/* Check that the device and any partitions will get valid
+	 * minor numbers and that the disk naming code below can cope
+	 * with this number. */
+	if (new->devnum > (MINORMASK >> tr->part_bits) ||
+	    (tr->part_bits && new->devnum >= 27 * 26))
 		return -EBUSY;
-	}
 
 	list_add_tail(&new->list, &tr->devs);
  added:
-- 
1.5.5


-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

[PATCHv3 9/9] mtdchar: Register the full range of minor numbers

[Ben Hutchings]

register_chrdev() registers minor numbers up to 255, but we can now
potentially have much larger numbers.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/mtd/mtdchar.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 04fd7e5..09b0ab5 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -955,7 +955,8 @@ static int __init init_mtdchar(void)
 {
 	int status;
 
-	status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
+	status = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
+				   "mtd", &mtd_fops);
 	if (status < 0) {
 		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 		       MTD_CHAR_MAJOR);
@@ -966,7 +967,7 @@ static int __init init_mtdchar(void)
 
 static void __exit cleanup_mtdchar(void)
 {
-	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
+	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
 }
 
 module_init(init_mtdchar);
-- 
1.5.5

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCHv3 6/9] idr: Export idr_get_next()

[Artem Bityutskiy]

On Fri, 2010-01-29 at 20:59 +0000, Ben Hutchings wrote:
> idr_get_next() was accidentally not exported when added.  It is about
> to be used by mtdcore, which may be built as a module.
> 
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

It is nicer to add an Ack you got from Hiroyuki. But I'll do this.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)

Re: [PATCHv3 0/9] mtd: Remove static limit on device numbers

[Artem Bityutskiy]

On Fri, 2010-01-29 at 20:55 +0000, Ben Hutchings wrote:
> This is the third version of this patch series.  Please give me some
> feedback, David?
> 
> Changes since v2:
> - Export idr_get_next() to support building mtdcore as a module
> - Correct the limit on block device numbers in mtd_blkdevs
> - Register the full range of minor numbers in mtdchar

Looks good for me. I did not test mtdblock, but tested that this does
not break UBIFS.

Pushed to my l2-mtd-2.6/master, thanks.
-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)

Re: [PATCHv3 0/9] mtd: Remove static limit on device numbers

[Ben Hutchings]

On Mon, 2010-02-08 at 17:54 +0200, Artem Bityutskiy wrote:
> On Fri, 2010-01-29 at 20:55 +0000, Ben Hutchings wrote:
> > This is the third version of this patch series.  Please give me some
> > feedback, David?
> > 
> > Changes since v2:
> > - Export idr_get_next() to support building mtdcore as a module
> > - Correct the limit on block device numbers in mtd_blkdevs
> > - Register the full range of minor numbers in mtdchar
> 
> Looks good for me. I did not test mtdblock, but tested that this does
> not break UBIFS.
> 
> Pushed to my l2-mtd-2.6/master, thanks.

Thanks a lot, Artem.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCHv3 4/9] mtd: Remove unnecessary comparisons with MAX_MTD_DEVICES

[David Woodhouse]

On Fri, 2010-01-29 at 20:58 +0000, Ben Hutchings wrote:
> 
> @@ -695,7 +695,7 @@ static int __init init_pmc551(void)
>         /*
>          * PCU-bus chipset probe.
>          */
> -       for (count = 0; count < MAX_MTD_DEVICES; count++) {
> +       for (;;) {
>  
>                 if ((PCI_Device = pci_get_device(PCI_VENDOR_ID_V3_SEMI,
>                                                   PCI_DEVICE_ID_V3_SEMI_V370PDC, 

Hm, that looks very overdue for being converted to a proper PCI driver.

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@intel.com                              Intel Corporation