[PATCH v3] mtd: implement proper partition handling

Miquel Raynal miquel.raynal at bootlin.com
Tue Jan 14 01:09:52 PST 2020


Instead of collecting partitions in a flat list, create a hierarchy
within the mtd_info structure: use a partitions list to keep track of
the partitions of an MTD device (which might be itself a partition of
another MTD device), a pointer to the parent device (NULL when the MTD
device is the root one, not a partition).

By also saving directly in mtd_info the offset of the partition, we
can get rid of the mtd_part structure.

While at it, be consistent in the naming of the mtd_info structures to
ease the understanding of the new hierarchy: these structures are
usually called 'mtd', unless there are multiple instances of the same
structure. In this case, there is usually a parent/child bound so we
will call them 'parent' and 'child'.

Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---

Change in v3:
* Keep the naming for the ->parent field but add more details in the
  mtd_master structure kernel documentation and the ->parent field of
  struct mtd_info that this parenting is from an MTD partition point
  of view, not from the device model perspective.

Changes in v2:
* Commit name changed "proper partition handling" -> "rework partition
  tree".
* Update mtd_get_device_size() to support recursive partitioning.
* Remove part_*() helpers, update the corresponding mtd_*() helpers to
  handle the partitions themselves.
* Drop the global partitions lock, add a lock per mtd_info but only use
  the root one to protect against partitions updates.

 drivers/mtd/mtdchar.c          |  12 +-
 drivers/mtd/mtdcore.c          | 250 ++++++++----
 drivers/mtd/mtdpart.c          | 697 +++++++++------------------------
 include/linux/mtd/mtd.h        | 125 +++++-
 include/linux/mtd/partitions.h |   1 -
 5 files changed, 479 insertions(+), 606 deletions(-)

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index b841008a9eb7..c5935b2f9cd1 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -349,6 +349,7 @@ static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 	uint64_t start, uint32_t length, void __user *ptr,
 	uint32_t __user *retp)
 {
+	struct mtd_info *master  = mtd_get_master(mtd);
 	struct mtd_file_info *mfi = file->private_data;
 	struct mtd_oob_ops ops = {};
 	uint32_t retlen;
@@ -360,7 +361,7 @@ static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 	if (length > 4096)
 		return -EINVAL;
 
-	if (!mtd->_write_oob)
+	if (!master->_write_oob)
 		return -EOPNOTSUPP;
 
 	ops.ooblen = length;
@@ -586,6 +587,7 @@ static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 static int mtdchar_write_ioctl(struct mtd_info *mtd,
 		struct mtd_write_req __user *argp)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
 	struct mtd_write_req req;
 	struct mtd_oob_ops ops = {};
 	const void __user *usr_data, *usr_oob;
@@ -597,9 +599,8 @@ static int mtdchar_write_ioctl(struct mtd_info *mtd,
 	usr_data = (const void __user *)(uintptr_t)req.usr_data;
 	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 
-	if (!mtd->_write_oob)
+	if (!master->_write_oob)
 		return -EOPNOTSUPP;
-
 	ops.mode = req.mode;
 	ops.len = (size_t)req.len;
 	ops.ooblen = (size_t)req.ooblen;
@@ -635,6 +636,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 {
 	struct mtd_file_info *mfi = file->private_data;
 	struct mtd_info *mtd = mfi->mtd;
+	struct mtd_info *master = mtd_get_master(mtd);
 	void __user *argp = (void __user *)arg;
 	int ret = 0;
 	struct mtd_info_user info;
@@ -824,7 +826,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 	{
 		struct nand_oobinfo oi;
 
-		if (!mtd->ooblayout)
+		if (!master->ooblayout)
 			return -EOPNOTSUPP;
 
 		ret = get_oobinfo(mtd, &oi);
@@ -918,7 +920,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 	{
 		struct nand_ecclayout_user *usrlay;
 
-		if (!mtd->ooblayout)
+		if (!master->ooblayout)
 			return -EOPNOTSUPP;
 
 		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 5fac4355b9c2..2916674208b3 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -456,13 +456,14 @@ static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
 			      struct mtd_pairing_info *info)
 {
-	int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
+	struct mtd_info *master = mtd_get_master(mtd);
+	int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
 
 	if (wunit < 0 || wunit >= npairs)
 		return -EINVAL;
 
-	if (mtd->pairing && mtd->pairing->get_info)
-		return mtd->pairing->get_info(mtd, wunit, info);
+	if (master->pairing && master->pairing->get_info)
+		return master->pairing->get_info(master, wunit, info);
 
 	info->group = 0;
 	info->pair = wunit;
@@ -498,15 +499,16 @@ EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
 			      const struct mtd_pairing_info *info)
 {
-	int ngroups = mtd_pairing_groups(mtd);
-	int npairs = mtd_wunit_per_eb(mtd) / ngroups;
+	struct mtd_info *master = mtd_get_master(mtd);
+	int ngroups = mtd_pairing_groups(master);
+	int npairs = mtd_wunit_per_eb(master) / ngroups;
 
 	if (!info || info->pair < 0 || info->pair >= npairs ||
 	    info->group < 0 || info->group >= ngroups)
 		return -EINVAL;
 
-	if (mtd->pairing && mtd->pairing->get_wunit)
-		return mtd->pairing->get_wunit(mtd, info);
+	if (master->pairing && master->pairing->get_wunit)
+		return mtd->pairing->get_wunit(master, info);
 
 	return info->pair;
 }
@@ -524,10 +526,12 @@ EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
  */
 int mtd_pairing_groups(struct mtd_info *mtd)
 {
-	if (!mtd->pairing || !mtd->pairing->ngroups)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->pairing || !master->pairing->ngroups)
 		return 1;
 
-	return mtd->pairing->ngroups;
+	return master->pairing->ngroups;
 }
 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
 
@@ -587,6 +591,7 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
 
 int add_mtd_device(struct mtd_info *mtd)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
 	struct mtd_notifier *not;
 	int i, error;
 
@@ -608,7 +613,7 @@ int add_mtd_device(struct mtd_info *mtd)
 		    (mtd->_read && mtd->_read_oob)))
 		return -EINVAL;
 
-	if (WARN_ON((!mtd->erasesize || !mtd->_erase) &&
+	if (WARN_ON((!mtd->erasesize || !master->_erase) &&
 		    !(mtd->flags & MTD_NO_ERASE)))
 		return -EINVAL;
 
@@ -765,7 +770,8 @@ static void mtd_set_dev_defaults(struct mtd_info *mtd)
 		pr_debug("mtd device won't show a device symlink in sysfs\n");
 	}
 
-	mtd->orig_flags = mtd->flags;
+	INIT_LIST_HEAD(&mtd->partitions);
+	mutex_init(&mtd->master.partitions_lock);
 }
 
 /**
@@ -971,20 +977,26 @@ EXPORT_SYMBOL_GPL(get_mtd_device);
 
 int __get_mtd_device(struct mtd_info *mtd)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
 	int err;
 
-	if (!try_module_get(mtd->owner))
+	if (!try_module_get(master->owner))
 		return -ENODEV;
 
-	if (mtd->_get_device) {
-		err = mtd->_get_device(mtd);
+	if (master->_get_device) {
+		err = master->_get_device(mtd);
 
 		if (err) {
-			module_put(mtd->owner);
+			module_put(master->owner);
 			return err;
 		}
 	}
-	mtd->usecount++;
+
+	while (mtd->parent) {
+		mtd->usecount++;
+		mtd = mtd->parent;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__get_mtd_device);
@@ -1038,13 +1050,18 @@ EXPORT_SYMBOL_GPL(put_mtd_device);
 
 void __put_mtd_device(struct mtd_info *mtd)
 {
-	--mtd->usecount;
-	BUG_ON(mtd->usecount < 0);
+	struct mtd_info *master = mtd_get_master(mtd);
 
-	if (mtd->_put_device)
-		mtd->_put_device(mtd);
+	while (mtd->parent) {
+		--mtd->usecount;
+		BUG_ON(mtd->usecount < 0);
+		mtd = mtd->parent;
+	}
 
-	module_put(mtd->owner);
+	if (master->_put_device)
+		master->_put_device(master);
+
+	module_put(master->owner);
 }
 EXPORT_SYMBOL_GPL(__put_mtd_device);
 
@@ -1055,9 +1072,13 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
  */
 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+	u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
+	int ret;
+
 	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
 
-	if (!mtd->erasesize || !mtd->_erase)
+	if (!mtd->erasesize || !master->_erase)
 		return -ENOTSUPP;
 
 	if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
@@ -1069,7 +1090,14 @@ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
 		return 0;
 
 	ledtrig_mtd_activity();
-	return mtd->_erase(mtd, instr);
+
+	instr->addr += mst_ofs;
+	ret = master->_erase(master, instr);
+	if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
+		instr->fail_addr -= mst_ofs;
+
+	instr->addr -= mst_ofs;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_erase);
 
@@ -1079,30 +1107,36 @@ EXPORT_SYMBOL_GPL(mtd_erase);
 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 	      void **virt, resource_size_t *phys)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	*retlen = 0;
 	*virt = NULL;
 	if (phys)
 		*phys = 0;
-	if (!mtd->_point)
+	if (!master->_point)
 		return -EOPNOTSUPP;
 	if (from < 0 || from >= mtd->size || len > mtd->size - from)
 		return -EINVAL;
 	if (!len)
 		return 0;
-	return mtd->_point(mtd, from, len, retlen, virt, phys);
+
+	from = mtd_get_master_ofs(mtd, from);
+	return master->_point(master, from, len, retlen, virt, phys);
 }
 EXPORT_SYMBOL_GPL(mtd_point);
 
 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 {
-	if (!mtd->_unpoint)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_unpoint)
 		return -EOPNOTSUPP;
 	if (from < 0 || from >= mtd->size || len > mtd->size - from)
 		return -EINVAL;
 	if (!len)
 		return 0;
-	return mtd->_unpoint(mtd, from, len);
+	return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
 }
 EXPORT_SYMBOL_GPL(mtd_unpoint);
 
@@ -1129,6 +1163,25 @@ unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
 }
 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
 
+static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
+				 const struct mtd_ecc_stats *old_stats)
+{
+	struct mtd_ecc_stats diff;
+
+	if (master == mtd)
+		return;
+
+	diff = master->ecc_stats;
+	diff.failed -= old_stats->failed;
+	diff.corrected -= old_stats->corrected;
+
+	while (mtd->parent) {
+		mtd->ecc_stats.failed += diff.failed;
+		mtd->ecc_stats.corrected += diff.corrected;
+		mtd = mtd->parent;
+	}
+}
+
 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 	     u_char *buf)
 {
@@ -1171,8 +1224,10 @@ EXPORT_SYMBOL_GPL(mtd_write);
 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
 		    const u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	*retlen = 0;
-	if (!mtd->_panic_write)
+	if (!master->_panic_write)
 		return -EOPNOTSUPP;
 	if (to < 0 || to >= mtd->size || len > mtd->size - to)
 		return -EINVAL;
@@ -1183,7 +1238,8 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
 	if (!mtd->oops_panic_write)
 		mtd->oops_panic_write = true;
 
-	return mtd->_panic_write(mtd, to, len, retlen, buf);
+	return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
+				    retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_panic_write);
 
@@ -1222,7 +1278,10 @@ static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
 
 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+	struct mtd_ecc_stats old_stats = master->ecc_stats;
 	int ret_code;
+
 	ops->retlen = ops->oobretlen = 0;
 
 	ret_code = mtd_check_oob_ops(mtd, from, ops);
@@ -1232,14 +1291,17 @@ int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
 	ledtrig_mtd_activity();
 
 	/* Check the validity of a potential fallback on mtd->_read */
-	if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
+	if (!master->_read_oob && (!master->_read || ops->oobbuf))
 		return -EOPNOTSUPP;
 
-	if (mtd->_read_oob)
-		ret_code = mtd->_read_oob(mtd, from, ops);
+	from = mtd_get_master_ofs(mtd, from);
+	if (master->_read_oob)
+		ret_code = master->_read_oob(master, from, ops);
 	else
-		ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
-				      ops->datbuf);
+		ret_code = master->_read(master, from, ops->len, &ops->retlen,
+					 ops->datbuf);
+
+	mtd_update_ecc_stats(mtd, master, &old_stats);
 
 	/*
 	 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
@@ -1258,6 +1320,7 @@ EXPORT_SYMBOL_GPL(mtd_read_oob);
 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
 				struct mtd_oob_ops *ops)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
 	int ret;
 
 	ops->retlen = ops->oobretlen = 0;
@@ -1272,14 +1335,16 @@ int mtd_write_oob(struct mtd_info *mtd, loff_t to,
 	ledtrig_mtd_activity();
 
 	/* Check the validity of a potential fallback on mtd->_write */
-	if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
+	if (!master->_write_oob && (!master->_write || ops->oobbuf))
 		return -EOPNOTSUPP;
 
-	if (mtd->_write_oob)
-		return mtd->_write_oob(mtd, to, ops);
+	to = mtd_get_master_ofs(mtd, to);
+
+	if (master->_write_oob)
+		return master->_write_oob(master, to, ops);
 	else
-		return mtd->_write(mtd, to, ops->len, &ops->retlen,
-				   ops->datbuf);
+		return master->_write(master, to, ops->len, &ops->retlen,
+				      ops->datbuf);
 }
 EXPORT_SYMBOL_GPL(mtd_write_oob);
 
@@ -1302,15 +1367,17 @@ EXPORT_SYMBOL_GPL(mtd_write_oob);
 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
 		      struct mtd_oob_region *oobecc)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	memset(oobecc, 0, sizeof(*oobecc));
 
-	if (!mtd || section < 0)
+	if (!master || section < 0)
 		return -EINVAL;
 
-	if (!mtd->ooblayout || !mtd->ooblayout->ecc)
+	if (!master->ooblayout || !master->ooblayout->ecc)
 		return -ENOTSUPP;
 
-	return mtd->ooblayout->ecc(mtd, section, oobecc);
+	return master->ooblayout->ecc(master, section, oobecc);
 }
 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
 
@@ -1334,15 +1401,17 @@ EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
 		       struct mtd_oob_region *oobfree)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	memset(oobfree, 0, sizeof(*oobfree));
 
-	if (!mtd || section < 0)
+	if (!master || section < 0)
 		return -EINVAL;
 
-	if (!mtd->ooblayout || !mtd->ooblayout->free)
+	if (!master->ooblayout || !master->ooblayout->free)
 		return -ENOTSUPP;
 
-	return mtd->ooblayout->free(mtd, section, oobfree);
+	return master->ooblayout->free(master, section, oobfree);
 }
 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
 
@@ -1651,60 +1720,69 @@ EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
 			   struct otp_info *buf)
 {
-	if (!mtd->_get_fact_prot_info)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_get_fact_prot_info)
 		return -EOPNOTSUPP;
 	if (!len)
 		return 0;
-	return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
+	return master->_get_fact_prot_info(master, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
 
 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
 			   size_t *retlen, u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	*retlen = 0;
-	if (!mtd->_read_fact_prot_reg)
+	if (!master->_read_fact_prot_reg)
 		return -EOPNOTSUPP;
 	if (!len)
 		return 0;
-	return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
+	return master->_read_fact_prot_reg(master, from, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
 
 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
 			   struct otp_info *buf)
 {
-	if (!mtd->_get_user_prot_info)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_get_user_prot_info)
 		return -EOPNOTSUPP;
 	if (!len)
 		return 0;
-	return mtd->_get_user_prot_info(mtd, len, retlen, buf);
+	return master->_get_user_prot_info(master, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
 
 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
 			   size_t *retlen, u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	*retlen = 0;
-	if (!mtd->_read_user_prot_reg)
+	if (!master->_read_user_prot_reg)
 		return -EOPNOTSUPP;
 	if (!len)
 		return 0;
-	return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
+	return master->_read_user_prot_reg(master, from, len, retlen, buf);
 }
 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
 
 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
 			    size_t *retlen, u_char *buf)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
 	int ret;
 
 	*retlen = 0;
-	if (!mtd->_write_user_prot_reg)
+	if (!master->_write_user_prot_reg)
 		return -EOPNOTSUPP;
 	if (!len)
 		return 0;
-	ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
+	ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
 	if (ret)
 		return ret;
 
@@ -1718,80 +1796,105 @@ EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
 
 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
 {
-	if (!mtd->_lock_user_prot_reg)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_lock_user_prot_reg)
 		return -EOPNOTSUPP;
 	if (!len)
 		return 0;
-	return mtd->_lock_user_prot_reg(mtd, from, len);
+	return master->_lock_user_prot_reg(master, from, len);
 }
 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
 
 /* Chip-supported device locking */
 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
-	if (!mtd->_lock)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_lock)
 		return -EOPNOTSUPP;
 	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
 		return -EINVAL;
 	if (!len)
 		return 0;
-	return mtd->_lock(mtd, ofs, len);
+	return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
 }
 EXPORT_SYMBOL_GPL(mtd_lock);
 
 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
-	if (!mtd->_unlock)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_unlock)
 		return -EOPNOTSUPP;
 	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
 		return -EINVAL;
 	if (!len)
 		return 0;
-	return mtd->_unlock(mtd, ofs, len);
+	return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
 }
 EXPORT_SYMBOL_GPL(mtd_unlock);
 
 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
-	if (!mtd->_is_locked)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_is_locked)
 		return -EOPNOTSUPP;
 	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
 		return -EINVAL;
 	if (!len)
 		return 0;
-	return mtd->_is_locked(mtd, ofs, len);
+	return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
 }
 EXPORT_SYMBOL_GPL(mtd_is_locked);
 
 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	if (ofs < 0 || ofs >= mtd->size)
 		return -EINVAL;
-	if (!mtd->_block_isreserved)
+	if (!master->_block_isreserved)
 		return 0;
-	return mtd->_block_isreserved(mtd, ofs);
+	return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
 }
 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
 
 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	if (ofs < 0 || ofs >= mtd->size)
 		return -EINVAL;
-	if (!mtd->_block_isbad)
+	if (!master->_block_isbad)
 		return 0;
-	return mtd->_block_isbad(mtd, ofs);
+	return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
 }
 EXPORT_SYMBOL_GPL(mtd_block_isbad);
 
 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
 {
-	if (!mtd->_block_markbad)
+	struct mtd_info *master = mtd_get_master(mtd);
+	int ret;
+
+	if (!master->_block_markbad)
 		return -EOPNOTSUPP;
 	if (ofs < 0 || ofs >= mtd->size)
 		return -EINVAL;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
-	return mtd->_block_markbad(mtd, ofs);
+
+	ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
+	if (ret)
+		return ret;
+
+	while (mtd->parent) {
+		mtd->ecc_stats.badblocks++;
+		mtd = mtd->parent;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mtd_block_markbad);
 
@@ -1841,12 +1944,17 @@ static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 	       unsigned long count, loff_t to, size_t *retlen)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
+
 	*retlen = 0;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
-	if (!mtd->_writev)
+
+	if (!master->_writev)
 		return default_mtd_writev(mtd, vecs, count, to, retlen);
-	return mtd->_writev(mtd, vecs, count, to, retlen);
+
+	return master->_writev(master, vecs, count,
+			       mtd_get_master_ofs(mtd, to), retlen);
 }
 EXPORT_SYMBOL_GPL(mtd_writev);
 
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 7328c066c5ba..93ef8fdf1634 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -20,339 +20,52 @@
 
 #include "mtdcore.h"
 
-/* Our partition linked list */
-static LIST_HEAD(mtd_partitions);
-static DEFINE_MUTEX(mtd_partitions_mutex);
-
-/**
- * struct mtd_part - our partition node structure
- *
- * @mtd: struct holding partition details
- * @parent: parent mtd - flash device or another partition
- * @offset: partition offset relative to the *flash device*
- */
-struct mtd_part {
-	struct mtd_info mtd;
-	struct mtd_info *parent;
-	uint64_t offset;
-	struct list_head list;
-};
-
-/*
- * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
- * the pointer to that structure.
- */
-static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
-{
-	return container_of(mtd, struct mtd_part, mtd);
-}
-
-static u64 part_absolute_offset(struct mtd_info *mtd)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	if (!mtd_is_partition(mtd))
-		return 0;
-
-	return part_absolute_offset(part->parent) + part->offset;
-}
-
 /*
  * MTD methods which simply translate the effective address and pass through
  * to the _real_ device.
  */
 
-static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
-		size_t *retlen, u_char *buf)
+static inline void free_partition(struct mtd_info *mtd)
 {
-	struct mtd_part *part = mtd_to_part(mtd);
-	struct mtd_ecc_stats stats;
-	int res;
-
-	stats = part->parent->ecc_stats;
-	res = part->parent->_read(part->parent, from + part->offset, len,
-				  retlen, buf);
-	if (unlikely(mtd_is_eccerr(res)))
-		mtd->ecc_stats.failed +=
-			part->parent->ecc_stats.failed - stats.failed;
-	else
-		mtd->ecc_stats.corrected +=
-			part->parent->ecc_stats.corrected - stats.corrected;
-	return res;
-}
-
-static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
-		size_t *retlen, void **virt, resource_size_t *phys)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	return part->parent->_point(part->parent, from + part->offset, len,
-				    retlen, virt, phys);
-}
-
-static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	return part->parent->_unpoint(part->parent, from + part->offset, len);
-}
-
-static int part_read_oob(struct mtd_info *mtd, loff_t from,
-		struct mtd_oob_ops *ops)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	struct mtd_ecc_stats stats;
-	int res;
-
-	stats = part->parent->ecc_stats;
-	res = part->parent->_read_oob(part->parent, from + part->offset, ops);
-	if (unlikely(mtd_is_eccerr(res)))
-		mtd->ecc_stats.failed +=
-			part->parent->ecc_stats.failed - stats.failed;
-	else
-		mtd->ecc_stats.corrected +=
-			part->parent->ecc_stats.corrected - stats.corrected;
-	return res;
-}
-
-static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
-		size_t len, size_t *retlen, u_char *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_read_user_prot_reg(part->parent, from, len,
-						 retlen, buf);
-}
-
-static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
-				   size_t *retlen, struct otp_info *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_get_user_prot_info(part->parent, len, retlen,
-						 buf);
-}
-
-static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
-		size_t len, size_t *retlen, u_char *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_read_fact_prot_reg(part->parent, from, len,
-						 retlen, buf);
-}
-
-static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
-				   size_t *retlen, struct otp_info *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_get_fact_prot_info(part->parent, len, retlen,
-						 buf);
-}
-
-static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
-		size_t *retlen, const u_char *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_write(part->parent, to + part->offset, len,
-				    retlen, buf);
-}
-
-static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
-		size_t *retlen, const u_char *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_panic_write(part->parent, to + part->offset, len,
-					  retlen, buf);
-}
-
-static int part_write_oob(struct mtd_info *mtd, loff_t to,
-		struct mtd_oob_ops *ops)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	return part->parent->_write_oob(part->parent, to + part->offset, ops);
-}
-
-static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
-		size_t len, size_t *retlen, u_char *buf)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_write_user_prot_reg(part->parent, from, len,
-						  retlen, buf);
-}
-
-static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
-		size_t len)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_lock_user_prot_reg(part->parent, from, len);
-}
-
-static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
-		unsigned long count, loff_t to, size_t *retlen)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_writev(part->parent, vecs, count,
-				     to + part->offset, retlen);
-}
-
-static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	int ret;
-
-	instr->addr += part->offset;
-	ret = part->parent->_erase(part->parent, instr);
-	if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
-		instr->fail_addr -= part->offset;
-	instr->addr -= part->offset;
-
-	return ret;
-}
-
-static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_lock(part->parent, ofs + part->offset, len);
-}
-
-static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_unlock(part->parent, ofs + part->offset, len);
-}
-
-static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_is_locked(part->parent, ofs + part->offset, len);
-}
-
-static void part_sync(struct mtd_info *mtd)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	part->parent->_sync(part->parent);
-}
-
-static int part_suspend(struct mtd_info *mtd)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_suspend(part->parent);
-}
-
-static void part_resume(struct mtd_info *mtd)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	part->parent->_resume(part->parent);
-}
-
-static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	ofs += part->offset;
-	return part->parent->_block_isreserved(part->parent, ofs);
-}
-
-static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	ofs += part->offset;
-	return part->parent->_block_isbad(part->parent, ofs);
-}
-
-static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	int res;
-
-	ofs += part->offset;
-	res = part->parent->_block_markbad(part->parent, ofs);
-	if (!res)
-		mtd->ecc_stats.badblocks++;
-	return res;
-}
-
-static int part_get_device(struct mtd_info *mtd)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	return part->parent->_get_device(part->parent);
-}
-
-static void part_put_device(struct mtd_info *mtd)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-	part->parent->_put_device(part->parent);
-}
-
-static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
-			      struct mtd_oob_region *oobregion)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	return mtd_ooblayout_ecc(part->parent, section, oobregion);
-}
-
-static int part_ooblayout_free(struct mtd_info *mtd, int section,
-			       struct mtd_oob_region *oobregion)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	return mtd_ooblayout_free(part->parent, section, oobregion);
-}
-
-static const struct mtd_ooblayout_ops part_ooblayout_ops = {
-	.ecc = part_ooblayout_ecc,
-	.free = part_ooblayout_free,
-};
-
-static int part_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
-{
-	struct mtd_part *part = mtd_to_part(mtd);
-
-	return part->parent->_max_bad_blocks(part->parent,
-					     ofs + part->offset, len);
-}
-
-static inline void free_partition(struct mtd_part *p)
-{
-	kfree(p->mtd.name);
-	kfree(p);
+	kfree(mtd->name);
+	kfree(mtd);
 }
 
-static struct mtd_part *allocate_partition(struct mtd_info *parent,
-			const struct mtd_partition *part, int partno,
-			uint64_t cur_offset)
+static struct mtd_info *allocate_partition(struct mtd_info *parent,
+					   const struct mtd_partition *part,
+					   int partno, uint64_t cur_offset)
 {
 	int wr_alignment = (parent->flags & MTD_NO_ERASE) ? parent->writesize :
 							    parent->erasesize;
-	struct mtd_part *slave;
+	struct mtd_info *child, *master = mtd_get_master(parent);
 	u32 remainder;
 	char *name;
 	u64 tmp;
 
 	/* allocate the partition structure */
-	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
+	child = kzalloc(sizeof(*child), GFP_KERNEL);
 	name = kstrdup(part->name, GFP_KERNEL);
-	if (!name || !slave) {
+	if (!name || !child) {
 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 		       parent->name);
 		kfree(name);
-		kfree(slave);
+		kfree(child);
 		return ERR_PTR(-ENOMEM);
 	}
 
 	/* set up the MTD object for this partition */
-	slave->mtd.type = parent->type;
-	slave->mtd.flags = parent->orig_flags & ~part->mask_flags;
-	slave->mtd.orig_flags = slave->mtd.flags;
-	slave->mtd.size = part->size;
-	slave->mtd.writesize = parent->writesize;
-	slave->mtd.writebufsize = parent->writebufsize;
-	slave->mtd.oobsize = parent->oobsize;
-	slave->mtd.oobavail = parent->oobavail;
-	slave->mtd.subpage_sft = parent->subpage_sft;
-	slave->mtd.pairing = parent->pairing;
+	child->type = parent->type;
+	child->part.flags = parent->flags & ~part->mask_flags;
+	child->flags = child->part.flags;
+	child->size = part->size;
+	child->writesize = parent->writesize;
+	child->writebufsize = parent->writebufsize;
+	child->oobsize = parent->oobsize;
+	child->oobavail = parent->oobavail;
+	child->subpage_sft = parent->subpage_sft;
 
-	slave->mtd.name = name;
-	slave->mtd.owner = parent->owner;
+	child->name = name;
+	child->owner = parent->owner;
 
 	/* NOTE: Historically, we didn't arrange MTDs as a tree out of
 	 * concern for showing the same data in multiple partitions.
@@ -360,134 +73,76 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
 	 * so the MTD_PARTITIONED_MASTER option allows that. The master
 	 * will have device nodes etc only if this is set, so make the
 	 * parent conditional on that option. Note, this is a way to
-	 * distinguish between the master and the partition in sysfs.
+	 * distinguish between the parent and its partitions in sysfs.
 	 */
-	slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
-				&parent->dev :
-				parent->dev.parent;
-	slave->mtd.dev.of_node = part->of_node;
-
-	if (parent->_read)
-		slave->mtd._read = part_read;
-	if (parent->_write)
-		slave->mtd._write = part_write;
-
-	if (parent->_panic_write)
-		slave->mtd._panic_write = part_panic_write;
-
-	if (parent->_point && parent->_unpoint) {
-		slave->mtd._point = part_point;
-		slave->mtd._unpoint = part_unpoint;
-	}
-
-	if (parent->_read_oob)
-		slave->mtd._read_oob = part_read_oob;
-	if (parent->_write_oob)
-		slave->mtd._write_oob = part_write_oob;
-	if (parent->_read_user_prot_reg)
-		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
-	if (parent->_read_fact_prot_reg)
-		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
-	if (parent->_write_user_prot_reg)
-		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
-	if (parent->_lock_user_prot_reg)
-		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
-	if (parent->_get_user_prot_info)
-		slave->mtd._get_user_prot_info = part_get_user_prot_info;
-	if (parent->_get_fact_prot_info)
-		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
-	if (parent->_sync)
-		slave->mtd._sync = part_sync;
-	if (!partno && !parent->dev.class && parent->_suspend &&
-	    parent->_resume) {
-		slave->mtd._suspend = part_suspend;
-		slave->mtd._resume = part_resume;
-	}
-	if (parent->_writev)
-		slave->mtd._writev = part_writev;
-	if (parent->_lock)
-		slave->mtd._lock = part_lock;
-	if (parent->_unlock)
-		slave->mtd._unlock = part_unlock;
-	if (parent->_is_locked)
-		slave->mtd._is_locked = part_is_locked;
-	if (parent->_block_isreserved)
-		slave->mtd._block_isreserved = part_block_isreserved;
-	if (parent->_block_isbad)
-		slave->mtd._block_isbad = part_block_isbad;
-	if (parent->_block_markbad)
-		slave->mtd._block_markbad = part_block_markbad;
-	if (parent->_max_bad_blocks)
-		slave->mtd._max_bad_blocks = part_max_bad_blocks;
-
-	if (parent->_get_device)
-		slave->mtd._get_device = part_get_device;
-	if (parent->_put_device)
-		slave->mtd._put_device = part_put_device;
-
-	slave->mtd._erase = part_erase;
-	slave->parent = parent;
-	slave->offset = part->offset;
-
-	if (slave->offset == MTDPART_OFS_APPEND)
-		slave->offset = cur_offset;
-	if (slave->offset == MTDPART_OFS_NXTBLK) {
+	child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
+			    &parent->dev : parent->dev.parent;
+	child->dev.of_node = part->of_node;
+	child->parent = parent;
+	child->part.offset = part->offset;
+	INIT_LIST_HEAD(&child->partitions);
+
+	if (child->part.offset == MTDPART_OFS_APPEND)
+		child->part.offset = cur_offset;
+	if (child->part.offset == MTDPART_OFS_NXTBLK) {
 		tmp = cur_offset;
-		slave->offset = cur_offset;
+		child->part.offset = cur_offset;
 		remainder = do_div(tmp, wr_alignment);
 		if (remainder) {
-			slave->offset += wr_alignment - remainder;
+			child->part.offset += wr_alignment - remainder;
 			printk(KERN_NOTICE "Moving partition %d: "
 			       "0x%012llx -> 0x%012llx\n", partno,
-			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
+			       (unsigned long long)cur_offset,
+			       child->part.offset);
 		}
 	}
-	if (slave->offset == MTDPART_OFS_RETAIN) {
-		slave->offset = cur_offset;
-		if (parent->size - slave->offset >= slave->mtd.size) {
-			slave->mtd.size = parent->size - slave->offset
-							- slave->mtd.size;
+	if (child->part.offset == MTDPART_OFS_RETAIN) {
+		child->part.offset = cur_offset;
+		if (parent->size - child->part.offset >= child->size) {
+			child->size = parent->size - child->part.offset -
+				      child->size;
 		} else {
 			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
-				part->name, parent->size - slave->offset,
-				slave->mtd.size);
+				part->name, parent->size - child->part.offset,
+				child->size);
 			/* register to preserve ordering */
 			goto out_register;
 		}
 	}
-	if (slave->mtd.size == MTDPART_SIZ_FULL)
-		slave->mtd.size = parent->size - slave->offset;
+	if (child->size == MTDPART_SIZ_FULL)
+		child->size = parent->size - child->part.offset;
 
-	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
-		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
+	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n",
+	       child->part.offset, child->part.offset + child->size,
+	       child->name);
 
 	/* let's do some sanity checks */
-	if (slave->offset >= parent->size) {
+	if (child->part.offset >= parent->size) {
 		/* let's register it anyway to preserve ordering */
-		slave->offset = 0;
-		slave->mtd.size = 0;
+		child->part.offset = 0;
+		child->size = 0;
 
 		/* Initialize ->erasesize to make add_mtd_device() happy. */
-		slave->mtd.erasesize = parent->erasesize;
-
+		child->erasesize = parent->erasesize;
 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 			part->name);
 		goto out_register;
 	}
-	if (slave->offset + slave->mtd.size > parent->size) {
-		slave->mtd.size = parent->size - slave->offset;
+	if (child->part.offset + child->size > parent->size) {
+		child->size = parent->size - child->part.offset;
 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
-			part->name, parent->name, (unsigned long long)slave->mtd.size);
+			part->name, parent->name, child->size);
 	}
 	if (parent->numeraseregions > 1) {
 		/* Deal with variable erase size stuff */
 		int i, max = parent->numeraseregions;
-		u64 end = slave->offset + slave->mtd.size;
+		u64 end = child->part.offset + child->size;
 		struct mtd_erase_region_info *regions = parent->eraseregions;
 
 		/* Find the first erase regions which is part of this
 		 * partition. */
-		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
+		for (i = 0; i < max && regions[i].offset <= child->part.offset;
+		     i++)
 			;
 		/* The loop searched for the region _behind_ the first one */
 		if (i > 0)
@@ -495,70 +150,68 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
 
 		/* Pick biggest erasesize */
 		for (; i < max && regions[i].offset < end; i++) {
-			if (slave->mtd.erasesize < regions[i].erasesize) {
-				slave->mtd.erasesize = regions[i].erasesize;
-			}
+			if (child->erasesize < regions[i].erasesize)
+				child->erasesize = regions[i].erasesize;
 		}
-		BUG_ON(slave->mtd.erasesize == 0);
+		BUG_ON(child->erasesize == 0);
 	} else {
 		/* Single erase size */
-		slave->mtd.erasesize = parent->erasesize;
+		child->erasesize = parent->erasesize;
 	}
 
 	/*
-	 * Slave erasesize might differ from the master one if the master
+	 * Child erasesize might differ from the parent one if the parent
 	 * exposes several regions with different erasesize. Adjust
 	 * wr_alignment accordingly.
 	 */
-	if (!(slave->mtd.flags & MTD_NO_ERASE))
-		wr_alignment = slave->mtd.erasesize;
+	if (!(child->flags & MTD_NO_ERASE))
+		wr_alignment = child->erasesize;
 
-	tmp = part_absolute_offset(parent) + slave->offset;
+	tmp = mtd_get_master_ofs(child, 0);
 	remainder = do_div(tmp, wr_alignment);
-	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
+	if ((child->flags & MTD_WRITEABLE) && remainder) {
 		/* Doesn't start on a boundary of major erase size */
 		/* FIXME: Let it be writable if it is on a boundary of
 		 * _minor_ erase size though */
-		slave->mtd.flags &= ~MTD_WRITEABLE;
+		child->flags &= ~MTD_WRITEABLE;
 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
 			part->name);
 	}
 
-	tmp = part_absolute_offset(parent) + slave->mtd.size;
+	tmp = mtd_get_master_ofs(child, 0) + child->size;
 	remainder = do_div(tmp, wr_alignment);
-	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
-		slave->mtd.flags &= ~MTD_WRITEABLE;
+	if ((child->flags & MTD_WRITEABLE) && remainder) {
+		child->flags &= ~MTD_WRITEABLE;
 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
 			part->name);
 	}
 
-	mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
-	slave->mtd.ecc_step_size = parent->ecc_step_size;
-	slave->mtd.ecc_strength = parent->ecc_strength;
-	slave->mtd.bitflip_threshold = parent->bitflip_threshold;
+	child->ecc_step_size = parent->ecc_step_size;
+	child->ecc_strength = parent->ecc_strength;
+	child->bitflip_threshold = parent->bitflip_threshold;
 
-	if (parent->_block_isbad) {
+	if (master->_block_isbad) {
 		uint64_t offs = 0;
 
-		while (offs < slave->mtd.size) {
-			if (mtd_block_isreserved(parent, offs + slave->offset))
-				slave->mtd.ecc_stats.bbtblocks++;
-			else if (mtd_block_isbad(parent, offs + slave->offset))
-				slave->mtd.ecc_stats.badblocks++;
-			offs += slave->mtd.erasesize;
+		while (offs < child->size) {
+			if (mtd_block_isreserved(child, offs))
+				child->ecc_stats.bbtblocks++;
+			else if (mtd_block_isbad(child, offs))
+				child->ecc_stats.badblocks++;
+			offs += child->erasesize;
 		}
 	}
 
 out_register:
-	return slave;
+	return child;
 }
 
 static ssize_t mtd_partition_offset_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct mtd_info *mtd = dev_get_drvdata(dev);
-	struct mtd_part *part = mtd_to_part(mtd);
-	return snprintf(buf, PAGE_SIZE, "%llu\n", part->offset);
+
+	return snprintf(buf, PAGE_SIZE, "%lld\n", mtd->part.offset);
 }
 
 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
@@ -568,9 +221,9 @@ static const struct attribute *mtd_partition_attrs[] = {
 	NULL
 };
 
-static int mtd_add_partition_attrs(struct mtd_part *new)
+static int mtd_add_partition_attrs(struct mtd_info *new)
 {
-	int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
+	int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs);
 	if (ret)
 		printk(KERN_WARNING
 		       "mtd: failed to create partition attrs, err=%d\n", ret);
@@ -580,8 +233,9 @@ static int mtd_add_partition_attrs(struct mtd_part *new)
 int mtd_add_partition(struct mtd_info *parent, const char *name,
 		      long long offset, long long length)
 {
+	struct mtd_info *master = mtd_get_master(parent);
 	struct mtd_partition part;
-	struct mtd_part *new;
+	struct mtd_info *child;
 	int ret = 0;
 
 	/* the direct offset is expected */
@@ -600,28 +254,28 @@ int mtd_add_partition(struct mtd_info *parent, const char *name,
 	part.size = length;
 	part.offset = offset;
 
-	new = allocate_partition(parent, &part, -1, offset);
-	if (IS_ERR(new))
-		return PTR_ERR(new);
+	child = allocate_partition(parent, &part, -1, offset);
+	if (IS_ERR(child))
+		return PTR_ERR(child);
 
-	mutex_lock(&mtd_partitions_mutex);
-	list_add(&new->list, &mtd_partitions);
-	mutex_unlock(&mtd_partitions_mutex);
+	mutex_lock(&master->master.partitions_lock);
+	list_add_tail(&child->part.node, &parent->partitions);
+	mutex_unlock(&master->master.partitions_lock);
 
-	ret = add_mtd_device(&new->mtd);
+	ret = add_mtd_device(child);
 	if (ret)
 		goto err_remove_part;
 
-	mtd_add_partition_attrs(new);
+	mtd_add_partition_attrs(child);
 
 	return 0;
 
 err_remove_part:
-	mutex_lock(&mtd_partitions_mutex);
-	list_del(&new->list);
-	mutex_unlock(&mtd_partitions_mutex);
+	mutex_lock(&master->master.partitions_lock);
+	list_del(&child->part.node);
+	mutex_unlock(&master->master.partitions_lock);
 
-	free_partition(new);
+	free_partition(child);
 
 	return ret;
 }
@@ -630,119 +284,142 @@ EXPORT_SYMBOL_GPL(mtd_add_partition);
 /**
  * __mtd_del_partition - delete MTD partition
  *
- * @priv: internal MTD struct for partition to be deleted
+ * @priv: MTD structure to be deleted
  *
  * This function must be called with the partitions mutex locked.
  */
-static int __mtd_del_partition(struct mtd_part *priv)
+static int __mtd_del_partition(struct mtd_info *mtd)
 {
-	struct mtd_part *child, *next;
+	struct mtd_info *child, *next;
 	int err;
 
-	list_for_each_entry_safe(child, next, &mtd_partitions, list) {
-		if (child->parent == &priv->mtd) {
-			err = __mtd_del_partition(child);
-			if (err)
-				return err;
-		}
+	list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
+		err = __mtd_del_partition(child);
+		if (err)
+			return err;
 	}
 
-	sysfs_remove_files(&priv->mtd.dev.kobj, mtd_partition_attrs);
+	sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs);
 
-	err = del_mtd_device(&priv->mtd);
+	err = del_mtd_device(mtd);
 	if (err)
 		return err;
 
-	list_del(&priv->list);
-	free_partition(priv);
+	list_del(&child->part.node);
+	free_partition(mtd);
 
 	return 0;
 }
 
 /*
  * This function unregisters and destroy all slave MTD objects which are
- * attached to the given MTD object.
+ * attached to the given MTD object, recursively.
  */
+int __del_mtd_partitions(struct mtd_info *mtd)
+{
+	struct mtd_info *child, *next;
+	LIST_HEAD(tmp_list);
+	int ret, err = 0;
+
+	list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
+		if (mtd_has_partitions(child))
+			del_mtd_partitions(child);
+
+		pr_info("Deleting %s MTD partition\n", child->name);
+		ret = del_mtd_device(child);
+		if (ret < 0) {
+			pr_err("Error when deleting partition \"%s\" (%d)\n",
+			       child->name, ret);
+			err = ret;
+			continue;
+		}
+
+		list_del(&child->part.node);
+		free_partition(child);
+	}
+
+	return err;
+}
+
 int del_mtd_partitions(struct mtd_info *mtd)
 {
-	struct mtd_part *slave, *next;
-	int ret, err = 0;
+	struct mtd_info *master = mtd_get_master(mtd);
+	int ret;
 
-	mutex_lock(&mtd_partitions_mutex);
-	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
-		if (slave->parent == mtd) {
-			ret = __mtd_del_partition(slave);
-			if (ret < 0)
-				err = ret;
-		}
-	mutex_unlock(&mtd_partitions_mutex);
+	pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name);
 
-	return err;
+	mutex_lock(&master->master.partitions_lock);
+	ret = __del_mtd_partitions(mtd);
+	mutex_unlock(&master->master.partitions_lock);
+
+	return ret;
 }
 
 int mtd_del_partition(struct mtd_info *mtd, int partno)
 {
-	struct mtd_part *slave, *next;
+	struct mtd_info *child, *master = mtd_get_master(mtd);
 	int ret = -EINVAL;
 
-	mutex_lock(&mtd_partitions_mutex);
-	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
-		if ((slave->parent == mtd) &&
-		    (slave->mtd.index == partno)) {
-			ret = __mtd_del_partition(slave);
+	mutex_lock(&master->master.partitions_lock);
+	list_for_each_entry(child, &mtd->partitions, part.node) {
+		if (child->index == partno) {
+			ret = __mtd_del_partition(child);
 			break;
 		}
-	mutex_unlock(&mtd_partitions_mutex);
+	}
+	mutex_unlock(&master->master.partitions_lock);
 
 	return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_del_partition);
 
 /*
- * This function, given a master MTD object and a partition table, creates
- * and registers slave MTD objects which are bound to the master according to
- * the partition definitions.
+ * This function, given a parent MTD object and a partition table, creates
+ * and registers the child MTD objects which are bound to the parent according
+ * to the partition definitions.
  *
- * For historical reasons, this function's caller only registers the master
+ * For historical reasons, this function's caller only registers the parent
  * if the MTD_PARTITIONED_MASTER config option is set.
  */
 
-int add_mtd_partitions(struct mtd_info *master,
+int add_mtd_partitions(struct mtd_info *parent,
 		       const struct mtd_partition *parts,
 		       int nbparts)
 {
-	struct mtd_part *slave;
+	struct mtd_info *child, *master = mtd_get_master(parent);
 	uint64_t cur_offset = 0;
 	int i, ret;
 
-	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
+	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n",
+	       nbparts, parent->name);
 
 	for (i = 0; i < nbparts; i++) {
-		slave = allocate_partition(master, parts + i, i, cur_offset);
-		if (IS_ERR(slave)) {
-			ret = PTR_ERR(slave);
+		child = allocate_partition(parent, parts + i, i, cur_offset);
+		if (IS_ERR(child)) {
+			ret = PTR_ERR(child);
 			goto err_del_partitions;
 		}
 
-		mutex_lock(&mtd_partitions_mutex);
-		list_add(&slave->list, &mtd_partitions);
-		mutex_unlock(&mtd_partitions_mutex);
+		mutex_lock(&master->master.partitions_lock);
+		list_add_tail(&child->part.node, &parent->partitions);
+		mutex_unlock(&master->master.partitions_lock);
 
-		ret = add_mtd_device(&slave->mtd);
+		ret = add_mtd_device(child);
 		if (ret) {
-			mutex_lock(&mtd_partitions_mutex);
-			list_del(&slave->list);
-			mutex_unlock(&mtd_partitions_mutex);
+			mutex_lock(&master->master.partitions_lock);
+			list_del(&child->part.node);
+			mutex_unlock(&master->master.partitions_lock);
 
-			free_partition(slave);
+			free_partition(child);
 			goto err_del_partitions;
 		}
 
-		mtd_add_partition_attrs(slave);
+		mtd_add_partition_attrs(child);
+
 		/* Look for subpartitions */
-		parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);
+		parse_mtd_partitions(child, parts[i].types, NULL);
 
-		cur_offset = slave->offset + slave->mtd.size;
+		cur_offset = child->part.offset + child->size;
 	}
 
 	return 0;
@@ -1023,29 +700,11 @@ void mtd_part_parser_cleanup(struct mtd_partitions *parts)
 	}
 }
 
-int mtd_is_partition(const struct mtd_info *mtd)
-{
-	struct mtd_part *part;
-	int ispart = 0;
-
-	mutex_lock(&mtd_partitions_mutex);
-	list_for_each_entry(part, &mtd_partitions, list)
-		if (&part->mtd == mtd) {
-			ispart = 1;
-			break;
-		}
-	mutex_unlock(&mtd_partitions_mutex);
-
-	return ispart;
-}
-EXPORT_SYMBOL_GPL(mtd_is_partition);
-
 /* Returns the size of the entire flash chip */
 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
 {
-	if (!mtd_is_partition(mtd))
-		return mtd->size;
+	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
 
-	return mtd_get_device_size(mtd_to_part(mtd)->parent);
+	return master->size;
 }
 EXPORT_SYMBOL_GPL(mtd_get_device_size);
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 249e8d9bfbcd..2d1f4a61f4ac 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -8,6 +8,7 @@
 
 #include <linux/types.h>
 #include <linux/uio.h>
+#include <linux/list.h>
 #include <linux/notifier.h>
 #include <linux/device.h>
 #include <linux/of.h>
@@ -194,10 +195,43 @@ struct mtd_debug_info {
 	const char *partid;
 };
 
+/**
+ * struct mtd_part - MTD partition specific fields
+ *
+ * @node: list node used to add an MTD partition to the parent partition list
+ * @offset: offset of the partition relatively to the parent offset
+ * @flags: original flags (before the mtdpart logic decided to tweak them based
+ *	   on flash constraints, like eraseblock/pagesize alignment)
+ *
+ * This struct is embedded in mtd_info and contains partition-specific
+ * properties/fields.
+ */
+struct mtd_part {
+	struct list_head node;
+	u64 offset;
+	u32 flags;
+};
+
+/**
+ * struct mtd_master - MTD master specific fields
+ *
+ * @partitions_lock: lock protecting accesses to the partition list. Protects
+ *		     not only the master partition list, but also all
+ *		     sub-partitions.
+ * @suspended: et to 1 when the device is suspended, 0 otherwise
+ *
+ * This struct is embedded in mtd_info and contains master-specific
+ * properties/fields. The master is the root MTD device from the MTD partition
+ * point of view.
+ */
+struct mtd_master {
+	struct mutex partitions_lock;
+	unsigned int suspended : 1;
+};
+
 struct mtd_info {
 	u_char type;
 	uint32_t flags;
-	uint32_t orig_flags; /* Flags as before running mtd checks */
 	uint64_t size;	 // Total size of the MTD
 
 	/* "Major" erase size for the device. Naïve users may take this
@@ -339,8 +373,52 @@ struct mtd_info {
 	int usecount;
 	struct mtd_debug_info dbg;
 	struct nvmem_device *nvmem;
+
+	/*
+	 * Parent device from the MTD partition point of view.
+	 *
+	 * MTD masters do not have any parent, MTD partitions do. The parent
+	 * MTD device can itself be a partition.
+	 */
+	struct mtd_info *parent;
+
+	/* List of partitions attached to this MTD device */
+	struct list_head partitions;
+
+	union {
+		struct mtd_part part;
+		struct mtd_master master;
+	};
 };
 
+static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
+{
+	while (mtd->parent)
+		mtd = mtd->parent;
+
+	return mtd;
+}
+
+static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
+{
+	while (mtd->parent) {
+		ofs += mtd->part.offset;
+		mtd = mtd->parent;
+	}
+
+	return ofs;
+}
+
+static inline bool mtd_is_partition(const struct mtd_info *mtd)
+{
+	return mtd->parent;
+}
+
+static inline bool mtd_has_partitions(const struct mtd_info *mtd)
+{
+	return !list_empty(&mtd->partitions);
+}
+
 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
 		      struct mtd_oob_region *oobecc);
 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
@@ -392,13 +470,16 @@ static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
 				     loff_t ofs, size_t len)
 {
-	if (!mtd->_max_bad_blocks)
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->_max_bad_blocks)
 		return -ENOTSUPP;
 
 	if (mtd->size < (len + ofs) || ofs < 0)
 		return -EINVAL;
 
-	return mtd->_max_bad_blocks(mtd, ofs, len);
+	return master->_max_bad_blocks(master, mtd_get_master_ofs(mtd, ofs),
+				       len);
 }
 
 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
@@ -439,8 +520,10 @@ int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 
 static inline void mtd_sync(struct mtd_info *mtd)
 {
-	if (mtd->_sync)
-		mtd->_sync(mtd);
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (master->_sync)
+		master->_sync(master);
 }
 
 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
@@ -452,13 +535,31 @@ int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
 
 static inline int mtd_suspend(struct mtd_info *mtd)
 {
-	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
+	struct mtd_info *master = mtd_get_master(mtd);
+	int ret;
+
+	if (master->master.suspended)
+		return 0;
+
+	ret = master->_suspend ? master->_suspend(master) : 0;
+	if (ret)
+		return ret;
+
+	master->master.suspended = 1;
+	return 0;
 }
 
 static inline void mtd_resume(struct mtd_info *mtd)
 {
-	if (mtd->_resume)
-		mtd->_resume(mtd);
+	struct mtd_info *master = mtd_get_master(mtd);
+
+	if (!master->master.suspended)
+		return;
+
+	if (master->_resume)
+		master->_resume(master);
+
+	master->master.suspended = 0;
 }
 
 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
@@ -538,7 +639,9 @@ static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
 
 static inline int mtd_has_oob(const struct mtd_info *mtd)
 {
-	return mtd->_read_oob && mtd->_write_oob;
+	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
+
+	return master->_read_oob && master->_write_oob;
 }
 
 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
@@ -548,7 +651,9 @@ static inline int mtd_type_is_nand(const struct mtd_info *mtd)
 
 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
 {
-	return !!mtd->_block_isbad;
+	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
+
+	return !!master->_block_isbad;
 }
 
 	/* Kernel-side ioctl definitions */
diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 11cb0c50cd84..e545c050d3e8 100644
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -105,7 +105,6 @@ extern void deregister_mtd_parser(struct mtd_part_parser *parser);
 	module_driver(__mtd_part_parser, register_mtd_parser, \
 		      deregister_mtd_parser)
 
-int mtd_is_partition(const struct mtd_info *mtd);
 int mtd_add_partition(struct mtd_info *master, const char *name,
 		      long long offset, long long length);
 int mtd_del_partition(struct mtd_info *master, int partno);
-- 
2.20.1




More information about the linux-mtd mailing list