mtd: fix partition wrapper functions

Linux-MTD Mailing List linux-mtd at lists.infradead.org
Mon Mar 26 20:59:14 EDT 2012


Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=994c8409c4591983898182bfb5a0368d3daf1fc1
Commit:     994c8409c4591983898182bfb5a0368d3daf1fc1
Parent:     31716a5ad32771be8339832b62aa030c263c6dac
Author:     Mike Dunn <mikedunn at newsguy.com>
AuthorDate: Sat Mar 3 13:13:06 2012 -0800
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Tue Mar 27 00:44:29 2012 +0100

    mtd: fix partition wrapper functions
    
    This patch reverts a change that may have been mistakenly included with the set
    of patches that introduced the new mtd api entry functions.  Or perhaps I am
    mistaken :)
    
    The problem is in the partition wrapper functions, where the calls to the driver
    methods were replaced with calls to the new mtd api functions.  This causes the
    api function to be called a second time, further down the call stack.  This is
    not only unnecessary and redundant - because the sanity checking code and (more
    restrictive) bounds checks for the partition were done in the first call - but
    is potentially problematic and confusing.
    
    For example, the call stack for a call to mtd_read() on a partitioned device
    currently looks like this:
    
    mtd_read()             gets struct mtd_info for the partition
    |
    +-> part_read()        via the pointer assigned when the partition was created
        |
        +->mtd_read()      this time gets struct mtd_info for the master
           |
           +->xyz_driver_read()  via the pointer asigned by the driver
    
    It seems that this can cause a variety of problems.  For example, if you want to
    add code to the api function that tests a value in mtd_info that is relevant
    only to the partition.  Or (in my case) you want the driver to return a value
    that may be different from that returned by the mtd api function.
    
    This patch eliminates the second call to the mtd api function.  It was tested on
    the docg4 nand driver with a subset of the api functions, but I inspected the
    rest and don't see any problems.
    
    Signed-off-by: Mike Dunn <mikedunn at newsguy.com>
    Signed-off-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 drivers/mtd/mtdpart.c |   60 +++++++++++++++++++++++++++----------------------
 1 files changed, 33 insertions(+), 27 deletions(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 33d32c6..226d28a 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -65,7 +65,8 @@ static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
 	int res;
 
 	stats = part->master->ecc_stats;
-	res = mtd_read(part->master, from + part->offset, len, retlen, buf);
+	res = part->master->_read(part->master, from + part->offset, len,
+				  retlen, buf);
 	if (unlikely(res)) {
 		if (mtd_is_bitflip(res))
 			mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
@@ -80,15 +81,15 @@ static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
 {
 	struct mtd_part *part = PART(mtd);
 
-	return mtd_point(part->master, from + part->offset, len, retlen,
-			 virt, phys);
+	return part->master->_point(part->master, 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 = PART(mtd);
 
-	return mtd_unpoint(part->master, from + part->offset, len);
+	return part->master->_unpoint(part->master, from + part->offset, len);
 }
 
 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
@@ -99,7 +100,8 @@ static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 	struct mtd_part *part = PART(mtd);
 
 	offset += part->offset;
-	return mtd_get_unmapped_area(part->master, len, offset, flags);
+	return part->master->_get_unmapped_area(part->master, len, offset,
+						flags);
 }
 
 static int part_read_oob(struct mtd_info *mtd, loff_t from,
@@ -130,7 +132,7 @@ static int part_read_oob(struct mtd_info *mtd, loff_t from,
 			return -EINVAL;
 	}
 
-	res = mtd_read_oob(part->master, from + part->offset, ops);
+	res = part->master->_read_oob(part->master, from + part->offset, ops);
 	if (unlikely(res)) {
 		if (mtd_is_bitflip(res))
 			mtd->ecc_stats.corrected++;
@@ -144,43 +146,46 @@ 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 = PART(mtd);
-	return mtd_read_user_prot_reg(part->master, from, len, retlen, buf);
+	return part->master->_read_user_prot_reg(part->master, from, len,
+						 retlen, buf);
 }
 
 static int part_get_user_prot_info(struct mtd_info *mtd,
 		struct otp_info *buf, size_t len)
 {
 	struct mtd_part *part = PART(mtd);
-	return mtd_get_user_prot_info(part->master, buf, len);
+	return part->master->_get_user_prot_info(part->master, buf, len);
 }
 
 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 = PART(mtd);
-	return mtd_read_fact_prot_reg(part->master, from, len, retlen, buf);
+	return part->master->_read_fact_prot_reg(part->master, from, len,
+						 retlen, buf);
 }
 
 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 		size_t len)
 {
 	struct mtd_part *part = PART(mtd);
-	return mtd_get_fact_prot_info(part->master, buf, len);
+	return part->master->_get_fact_prot_info(part->master, buf, len);
 }
 
 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 = PART(mtd);
-	return mtd_write(part->master, to + part->offset, len, retlen, buf);
+	return part->master->_write(part->master, 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 = PART(mtd);
-	return mtd_panic_write(part->master, to + part->offset, len, retlen,
-			       buf);
+	return part->master->_panic_write(part->master, to + part->offset, len,
+					  retlen, buf);
 }
 
 static int part_write_oob(struct mtd_info *mtd, loff_t to,
@@ -192,29 +197,30 @@ static int part_write_oob(struct mtd_info *mtd, loff_t to,
 		return -EINVAL;
 	if (ops->datbuf && to + ops->len > mtd->size)
 		return -EINVAL;
-	return mtd_write_oob(part->master, to + part->offset, ops);
+	return part->master->_write_oob(part->master, 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 = PART(mtd);
-	return mtd_write_user_prot_reg(part->master, from, len, retlen, buf);
+	return part->master->_write_user_prot_reg(part->master, 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 = PART(mtd);
-	return mtd_lock_user_prot_reg(part->master, from, len);
+	return part->master->_lock_user_prot_reg(part->master, 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 = PART(mtd);
-	return mtd_writev(part->master, vecs, count, to + part->offset,
-			  retlen);
+	return part->master->_writev(part->master, vecs, count,
+				     to + part->offset, retlen);
 }
 
 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
@@ -223,7 +229,7 @@ static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 	int ret;
 
 	instr->addr += part->offset;
-	ret = mtd_erase(part->master, instr);
+	ret = part->master->_erase(part->master, instr);
 	if (ret) {
 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 			instr->fail_addr -= part->offset;
@@ -249,44 +255,44 @@ EXPORT_SYMBOL_GPL(mtd_erase_callback);
 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	struct mtd_part *part = PART(mtd);
-	return mtd_lock(part->master, ofs + part->offset, len);
+	return part->master->_lock(part->master, ofs + part->offset, len);
 }
 
 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	struct mtd_part *part = PART(mtd);
-	return mtd_unlock(part->master, ofs + part->offset, len);
+	return part->master->_unlock(part->master, ofs + part->offset, len);
 }
 
 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	struct mtd_part *part = PART(mtd);
-	return mtd_is_locked(part->master, ofs + part->offset, len);
+	return part->master->_is_locked(part->master, ofs + part->offset, len);
 }
 
 static void part_sync(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
-	mtd_sync(part->master);
+	part->master->_sync(part->master);
 }
 
 static int part_suspend(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
-	return mtd_suspend(part->master);
+	return part->master->_suspend(part->master);
 }
 
 static void part_resume(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
-	mtd_resume(part->master);
+	part->master->_resume(part->master);
 }
 
 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
 	struct mtd_part *part = PART(mtd);
 	ofs += part->offset;
-	return mtd_block_isbad(part->master, ofs);
+	return part->master->_block_isbad(part->master, ofs);
 }
 
 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
@@ -295,7 +301,7 @@ static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 	int res;
 
 	ofs += part->offset;
-	res = mtd_block_markbad(part->master, ofs);
+	res = part->master->_block_markbad(part->master, ofs);
 	if (!res)
 		mtd->ecc_stats.badblocks++;
 	return res;



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