From dcec4c3bdc4d5f4bd2d858ee1ce11e3424cbaed7 Mon Sep 17 00:00:00 2001
From: Florin Malita <fmalita@gmail.com>
Date: Thu, 19 Jul 2007 15:22:41 -0400
Subject: [PATCH 01/15] UBI: fix leak in ubi_scan_erase_peb

Coverity (1769) found the following problem: if the erase counter
overflow check triggers, ec_hdr is leaked.

Moving the allocation after the overflow check should take care of it.

Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/scan.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 94ee54934411..80c73d88c83f 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -673,10 +673,6 @@ int ubi_scan_erase_peb(const struct ubi_device *ubi,
 	int err;
 	struct ubi_ec_hdr *ec_hdr;
 
-	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
-	if (!ec_hdr)
-		return -ENOMEM;
-
 	if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 		/*
 		 * Erase counter overflow. Upgrade UBI and use 64-bit
@@ -686,6 +682,10 @@ int ubi_scan_erase_peb(const struct ubi_device *ubi,
 		return -EINVAL;
 	}
 
+	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	if (!ec_hdr)
+		return -ENOMEM;
+
 	ec_hdr->ec = cpu_to_be64(ec);
 
 	err = ubi_io_sync_erase(ubi, pnum, 0);

From 8bc22961966b845aa5f965be30771902146c2fcc Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Sun, 22 Jul 2007 15:25:02 +0300
Subject: [PATCH 02/15] UBI: fix sparse warnings

Fix "symbol shadows an earlier one" warnings. Although they are harmless
but it does not hurt to fix them and make sparse happy.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/scan.c | 16 +++++-----
 drivers/mtd/ubi/vmt.c  | 70 ++++++++++++++++++++++--------------------
 2 files changed, 45 insertions(+), 41 deletions(-)

diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 80c73d88c83f..18c347b24e27 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -266,7 +266,7 @@ static int compare_lebs(const struct ubi_device *ubi,
 	void *buf;
 	int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 	uint32_t data_crc, crc;
-	struct ubi_vid_hdr *vidh = NULL;
+	struct ubi_vid_hdr *vh = NULL;
 	unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 
 	if (seb->sqnum == 0 && sqnum2 == 0) {
@@ -323,11 +323,11 @@ static int compare_lebs(const struct ubi_device *ubi,
 	} else {
 		pnum = seb->pnum;
 
-		vidh = ubi_zalloc_vid_hdr(ubi);
-		if (!vidh)
+		vh = ubi_zalloc_vid_hdr(ubi);
+		if (!vh)
 			return -ENOMEM;
 
-		err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
+		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 		if (err) {
 			if (err == UBI_IO_BITFLIPS)
 				bitflips = 1;
@@ -341,7 +341,7 @@ static int compare_lebs(const struct ubi_device *ubi,
 			}
 		}
 
-		if (!vidh->copy_flag) {
+		if (!vh->copy_flag) {
 			/* It is not a copy, so it is newer */
 			dbg_bld("first PEB %d is newer, copy_flag is unset",
 				pnum);
@@ -349,7 +349,7 @@ static int compare_lebs(const struct ubi_device *ubi,
 			goto out_free_vidh;
 		}
 
-		vid_hdr = vidh;
+		vid_hdr = vh;
 	}
 
 	/* Read the data of the copy and check the CRC */
@@ -379,7 +379,7 @@ static int compare_lebs(const struct ubi_device *ubi,
 	}
 
 	vfree(buf);
-	ubi_free_vid_hdr(ubi, vidh);
+	ubi_free_vid_hdr(ubi, vh);
 
 	if (second_is_newer)
 		dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
@@ -391,7 +391,7 @@ static int compare_lebs(const struct ubi_device *ubi,
 out_free_buf:
 	vfree(buf);
 out_free_vidh:
-	ubi_free_vid_hdr(ubi, vidh);
+	ubi_free_vid_hdr(ubi, vh);
 	ubi_assert(err < 0);
 	return err;
 }
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index ea0d5c825ab4..88629a320c2b 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -37,21 +37,21 @@ static ssize_t vol_attribute_show(struct device *dev,
 				  struct device_attribute *attr, char *buf);
 
 /* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
-static struct device_attribute vol_reserved_ebs =
+static struct device_attribute attr_vol_reserved_ebs =
 	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_type =
+static struct device_attribute attr_vol_type =
 	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_name =
+static struct device_attribute attr_vol_name =
 	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_corrupted =
+static struct device_attribute attr_vol_corrupted =
 	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_alignment =
+static struct device_attribute attr_vol_alignment =
 	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_usable_eb_size =
+static struct device_attribute attr_vol_usable_eb_size =
 	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_data_bytes =
+static struct device_attribute attr_vol_data_bytes =
 	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
-static struct device_attribute vol_upd_marker =
+static struct device_attribute attr_vol_upd_marker =
 	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
 
 /*
@@ -78,23 +78,27 @@ static ssize_t vol_attribute_show(struct device *dev,
 		spin_unlock(&vol->ubi->volumes_lock);
 		return -ENODEV;
 	}
-	if (attr == &vol_reserved_ebs)
+	if (attr == &attr_vol_reserved_ebs)
 		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
-	else if (attr == &vol_type) {
+	else if (attr == &attr_vol_type) {
 		const char *tp;
-		tp = vol->vol_type == UBI_DYNAMIC_VOLUME ? "dynamic" : "static";
+
+		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+			tp = "dynamic";
+		else
+			tp = "static";
 		ret = sprintf(buf, "%s\n", tp);
-	} else if (attr == &vol_name)
+	} else if (attr == &attr_vol_name)
 		ret = sprintf(buf, "%s\n", vol->name);
-	else if (attr == &vol_corrupted)
+	else if (attr == &attr_vol_corrupted)
 		ret = sprintf(buf, "%d\n", vol->corrupted);
-	else if (attr == &vol_alignment)
+	else if (attr == &attr_vol_alignment)
 		ret = sprintf(buf, "%d\n", vol->alignment);
-	else if (attr == &vol_usable_eb_size) {
+	else if (attr == &attr_vol_usable_eb_size) {
 		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
-	} else if (attr == &vol_data_bytes)
+	} else if (attr == &attr_vol_data_bytes)
 		ret = sprintf(buf, "%lld\n", vol->used_bytes);
-	else if (attr == &vol_upd_marker)
+	else if (attr == &attr_vol_upd_marker)
 		ret = sprintf(buf, "%d\n", vol->upd_marker);
 	else
 		BUG();
@@ -126,28 +130,28 @@ static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
 {
 	int err;
 
-	err = device_create_file(&vol->dev, &vol_reserved_ebs);
+	err = device_create_file(&vol->dev, &attr_vol_reserved_ebs);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_type);
+	err = device_create_file(&vol->dev, &attr_vol_type);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_name);
+	err = device_create_file(&vol->dev, &attr_vol_name);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_corrupted);
+	err = device_create_file(&vol->dev, &attr_vol_corrupted);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_alignment);
+	err = device_create_file(&vol->dev, &attr_vol_alignment);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_usable_eb_size);
+	err = device_create_file(&vol->dev, &attr_vol_usable_eb_size);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_data_bytes);
+	err = device_create_file(&vol->dev, &attr_vol_data_bytes);
 	if (err)
 		return err;
-	err = device_create_file(&vol->dev, &vol_upd_marker);
+	err = device_create_file(&vol->dev, &attr_vol_upd_marker);
 	if (err)
 		return err;
 	return 0;
@@ -159,14 +163,14 @@ static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
  */
 static void volume_sysfs_close(struct ubi_volume *vol)
 {
-	device_remove_file(&vol->dev, &vol_upd_marker);
-	device_remove_file(&vol->dev, &vol_data_bytes);
-	device_remove_file(&vol->dev, &vol_usable_eb_size);
-	device_remove_file(&vol->dev, &vol_alignment);
-	device_remove_file(&vol->dev, &vol_corrupted);
-	device_remove_file(&vol->dev, &vol_name);
-	device_remove_file(&vol->dev, &vol_type);
-	device_remove_file(&vol->dev, &vol_reserved_ebs);
+	device_remove_file(&vol->dev, &attr_vol_upd_marker);
+	device_remove_file(&vol->dev, &attr_vol_data_bytes);
+	device_remove_file(&vol->dev, &attr_vol_usable_eb_size);
+	device_remove_file(&vol->dev, &attr_vol_alignment);
+	device_remove_file(&vol->dev, &attr_vol_corrupted);
+	device_remove_file(&vol->dev, &attr_vol_name);
+	device_remove_file(&vol->dev, &attr_vol_type);
+	device_remove_file(&vol->dev, &attr_vol_reserved_ebs);
 	device_unregister(&vol->dev);
 }
 

From 8d2d4011f1398d984819c65043abb559c451a3c8 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Sun, 22 Jul 2007 22:32:51 +0300
Subject: [PATCH 03/15] UBI: add more prints

I hit those situations and found out lack of print messages. Add more prints
when erase problems occur.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/io.c | 5 ++++-
 drivers/mtd/ubi/wl.c | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index b0d8f4cede97..d42ec687b014 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -430,13 +430,16 @@ static int torture_peb(const struct ubi_device *ubi, int pnum)
 	err = patt_count;
 
 out:
-	if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
+	if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
 		/*
 		 * If a bit-flip or data integrity error was detected, the test
 		 * has not passed because it happened on a freshly erased
 		 * physical eraseblock which means something is wrong with it.
 		 */
+		ubi_err("read problems on freshly erased PEB %d, must be bad",
+			pnum);
 		err = -EIO;
+	}
 	vfree(buf);
 	return err;
 }
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index a5a9b8d87302..12b25e5b7b81 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1093,6 +1093,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 		return err;
 	}
 
+	ubi_err("failed to erase PEB %d, error %d", pnum, err);
 	kfree(wl_wrk);
 	kmem_cache_free(wl_entries_slab, e);
 

From 0169b49d52400a6035cd0f2ccd08bcba061a1a9b Mon Sep 17 00:00:00 2001
From: Jesper Juhl <jesper.juhl@gmail.com>
Date: Sat, 4 Aug 2007 01:25:26 +0200
Subject: [PATCH 04/15] UBI: don't use array index before testing if it is
 negative

I can't find anything guaranteeing that 'ubi_num' cannot be <0 in
drivers/mtd/ubi/kapi.c::ubi_open_volume(), and in fact the code
even tests for that and errors out if so. Unfortunately the test
for "ubi_num < 0" happens after we've already used 'ubi_num' as
an array index - bad thing to do if it is negative.
This patch moves the test earlier in the function and then moves
the indexing using that variable after the check. A bit safer :-)

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/kapi.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 4a458e83e4e9..03c774f41549 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -99,16 +99,21 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
 {
 	int err;
 	struct ubi_volume_desc *desc;
-	struct ubi_device *ubi = ubi_devices[ubi_num];
+	struct ubi_device *ubi;
 	struct ubi_volume *vol;
 
 	dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
 
 	err = -ENODEV;
+	if (ubi_num < 0)
+		return ERR_PTR(err);
+
+	ubi = ubi_devices[ubi_num];
+
 	if (!try_module_get(THIS_MODULE))
 		return ERR_PTR(err);
 
-	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi)
+	if (ubi_num >= UBI_MAX_DEVICES || !ubi)
 		goto out_put;
 
 	err = -EINVAL;

From ef6075fbfca9139f428d52d60e671da38aa2e212 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Tue, 7 Aug 2007 23:34:20 +0300
Subject: [PATCH 05/15] UBI: use linux print_hex_dump(), not home-grown one

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/debug.c | 37 ++-----------------------------------
 drivers/mtd/ubi/debug.h |  2 --
 drivers/mtd/ubi/io.c    |  2 +-
 3 files changed, 3 insertions(+), 38 deletions(-)

diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 310341e5cd43..785137435185 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -42,7 +42,8 @@ void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
 	dbg_msg("data_offset    %d",    be32_to_cpu(ec_hdr->data_offset));
 	dbg_msg("hdr_crc        %#08x", be32_to_cpu(ec_hdr->hdr_crc));
 	dbg_msg("erase counter header hexdump:");
-	ubi_dbg_hexdump(ec_hdr, UBI_EC_HDR_SIZE);
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4,
+		       (void *)ec_hdr, UBI_EC_HDR_SIZE, 1);
 }
 
 /**
@@ -187,38 +188,4 @@ void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req)
 	dbg_msg("the 1st 16 characters of the name: %s", nm);
 }
 
-#define BYTES_PER_LINE 32
-
-/**
- * ubi_dbg_hexdump - dump a buffer.
- * @ptr: the buffer to dump
- * @size: buffer size which must be multiple of 4 bytes
- */
-void ubi_dbg_hexdump(const void *ptr, int size)
-{
-	int i, k = 0, rows, columns;
-	const uint8_t *p = ptr;
-
-	size = ALIGN(size, 4);
-	rows = size/BYTES_PER_LINE + size % BYTES_PER_LINE;
-	for (i = 0; i < rows; i++) {
-		int j;
-
-		cond_resched();
-		columns = min(size - k, BYTES_PER_LINE) / 4;
-		if (columns == 0)
-			break;
-		printk(KERN_DEBUG "%5d:  ", i * BYTES_PER_LINE);
-		for (j = 0; j < columns; j++) {
-			int n, N;
-
-			N = size - k > 4 ? 4 : size - k;
-			for (n = 0; n < N; n++)
-				printk("%02x", p[k++]);
-			printk(" ");
-		}
-		printk("\n");
-	}
-}
-
 #endif /* CONFIG_MTD_UBI_DEBUG_MSG */
diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index ff8f39548cd8..467722eb618b 100644
--- a/drivers/mtd/ubi/debug.h
+++ b/drivers/mtd/ubi/debug.h
@@ -59,7 +59,6 @@ void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx);
 void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv);
 void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type);
 void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req);
-void ubi_dbg_hexdump(const void *buf, int size);
 
 #else
 
@@ -72,7 +71,6 @@ void ubi_dbg_hexdump(const void *buf, int size);
 #define ubi_dbg_dump_sv(sv)              ({})
 #define ubi_dbg_dump_seb(seb, type)      ({})
 #define ubi_dbg_dump_mkvol_req(req)      ({})
-#define ubi_dbg_hexdump(buf, size)       ({})
 
 #endif /* CONFIG_MTD_UBI_DEBUG_MSG */
 
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index d42ec687b014..928476394d55 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -1252,7 +1252,7 @@ static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum,
 fail:
 	ubi_err("paranoid check failed for PEB %d", pnum);
 	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
-	ubi_dbg_hexdump(buf, len);
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
 	err = 1;
 error:
 	ubi_dbg_dump_stack();

From 33818bbb84cd371b63ed8849cc5264d24c8b3aa2 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Tue, 28 Aug 2007 21:29:32 +0300
Subject: [PATCH 06/15] UBI: allocate memory with GFP_NOFS

Use GFP_NOFS flag when allocating memory on I/O path, because otherwise
we may deadlock the filesystem which works on top of us. We observed
the deadlocks with UBIFS. Example:

VFS->FS lock a lock->UBI->kmalloc()->VFS writeback->FS locks the same
lock again.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/eba.c  | 12 ++++++------
 drivers/mtd/ubi/io.c   |  4 ++--
 drivers/mtd/ubi/scan.c |  4 ++--
 drivers/mtd/ubi/ubi.h  |  6 ++++--
 drivers/mtd/ubi/vtbl.c |  2 +-
 drivers/mtd/ubi/wl.c   | 12 ++++++------
 6 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 7c5e29eaf118..89193104c6c8 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -157,7 +157,7 @@ static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id,
 {
 	struct ltree_entry *le, *le1, *le_free;
 
-	le = kmem_cache_alloc(ltree_slab, GFP_KERNEL);
+	le = kmem_cache_alloc(ltree_slab, GFP_NOFS);
 	if (!le)
 		return ERR_PTR(-ENOMEM);
 
@@ -397,7 +397,7 @@ int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
 
 retry:
 	if (check) {
-		vid_hdr = ubi_zalloc_vid_hdr(ubi);
+		vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 		if (!vid_hdr) {
 			err = -ENOMEM;
 			goto out_unlock;
@@ -497,7 +497,7 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
 	struct ubi_vid_hdr *vid_hdr;
 	unsigned char *new_buf;
 
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr) {
 		return -ENOMEM;
 	}
@@ -627,7 +627,7 @@ int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
 	 * The logical eraseblock is not mapped. We have to get a free physical
 	 * eraseblock and write the volume identifier header there first.
 	 */
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr) {
 		leb_write_unlock(ubi, vol_id, lnum);
 		return -ENOMEM;
@@ -738,7 +738,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
 	else
 		ubi_assert(len % ubi->min_io_size == 0);
 
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr)
 		return -ENOMEM;
 
@@ -844,7 +844,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
 	if (ubi->ro_mode)
 		return -EROFS;
 
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr)
 		return -ENOMEM;
 
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 928476394d55..ba5bc4a5379e 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -1099,7 +1099,7 @@ static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
 	uint32_t crc, hdr_crc;
 	struct ubi_ec_hdr *ec_hdr;
 
-	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
 	if (!ec_hdr)
 		return -ENOMEM;
 
@@ -1179,7 +1179,7 @@ static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
 	struct ubi_vid_hdr *vid_hdr;
 	void *p;
 
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr)
 		return -ENOMEM;
 
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 18c347b24e27..1c1401d6958b 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -323,7 +323,7 @@ static int compare_lebs(const struct ubi_device *ubi,
 	} else {
 		pnum = seb->pnum;
 
-		vh = ubi_zalloc_vid_hdr(ubi);
+		vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 		if (!vh)
 			return -ENOMEM;
 
@@ -948,7 +948,7 @@ struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 	if (!ech)
 		goto out_si;
 
-	vidh = ubi_zalloc_vid_hdr(ubi);
+	vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 	if (!vidh)
 		goto out_ech;
 
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 5959f91be240..329663188772 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -439,16 +439,18 @@ int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum,
 /**
  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
  * @ubi: UBI device description object
+ * @gfp_flags: GFP flags to allocate with
  *
  * This function returns a pointer to the newly allocated and zero-filled
  * volume identifier header object in case of success and %NULL in case of
  * failure.
  */
-static inline struct ubi_vid_hdr *ubi_zalloc_vid_hdr(const struct ubi_device *ubi)
+static inline struct ubi_vid_hdr *
+ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 {
 	void *vid_hdr;
 
-	vid_hdr = kzalloc(ubi->vid_hdr_alsize, GFP_KERNEL);
+	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 	if (!vid_hdr)
 		return NULL;
 
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index bc5df50813d6..b0a1e8426456 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -264,7 +264,7 @@ static int create_vtbl(const struct ubi_device *ubi, struct ubi_scan_info *si,
 
 	ubi_msg("create volume table (copy #%d)", copy + 1);
 
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 	if (!vid_hdr)
 		return -ENOMEM;
 
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 12b25e5b7b81..248ff9e477e7 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -508,7 +508,7 @@ int ubi_wl_get_peb(struct ubi_device *ubi, int dtype)
 	ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM ||
 		   dtype == UBI_UNKNOWN);
 
-	pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_KERNEL);
+	pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
 	if (!pe)
 		return -ENOMEM;
 
@@ -645,7 +645,7 @@ static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int tortur
 	if (err > 0)
 		return -EINVAL;
 
-	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
 	if (!ec_hdr)
 		return -ENOMEM;
 
@@ -768,7 +768,7 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
 	dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
 	       e->pnum, e->ec, torture);
 
-	wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_KERNEL);
+	wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
 	if (!wl_wrk)
 		return -ENOMEM;
 
@@ -802,7 +802,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 	if (cancel)
 		return 0;
 
-	vid_hdr = ubi_zalloc_vid_hdr(ubi);
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr)
 		return -ENOMEM;
 
@@ -1028,7 +1028,7 @@ static int ensure_wear_leveling(struct ubi_device *ubi)
 	ubi->wl_scheduled = 1;
 	spin_unlock(&ubi->wl_lock);
 
-	wrk = kmalloc(sizeof(struct ubi_work), GFP_KERNEL);
+	wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
 	if (!wrk) {
 		err = -ENOMEM;
 		goto out_cancel;
@@ -1631,7 +1631,7 @@ static int paranoid_check_ec(const struct ubi_device *ubi, int pnum, int ec)
 	long long read_ec;
 	struct ubi_ec_hdr *ec_hdr;
 
-	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
 	if (!ec_hdr)
 		return -ENOMEM;
 

From e88d6e10e5c848fd5be8f89e09e3bce2570886b7 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Wed, 29 Aug 2007 14:51:52 +0300
Subject: [PATCH 07/15] UBI: do not use vmalloc on I/O path

Similar reason as in case of the previous patch: it causes
deadlocks if a filesystem with writeback support works on top
of UBI. So pre-allocate needed buffers when attaching MTD device.
We also need mutexes to protect the buffers, but they do not
cause much contantion because they are used in recovery, torture,
and WL copy routines, which are called seldom.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/build.c | 28 ++++++++++++++++-
 drivers/mtd/ubi/eba.c   | 70 ++++++++++++++---------------------------
 drivers/mtd/ubi/io.c    | 66 +++++++++++++++++---------------------
 drivers/mtd/ubi/scan.c  | 19 +++++------
 drivers/mtd/ubi/scan.h  |  8 ++---
 drivers/mtd/ubi/ubi.h   | 30 +++++++++++++-----
 drivers/mtd/ubi/vtbl.c  |  6 ++--
 drivers/mtd/ubi/wl.c    |  4 +--
 8 files changed, 119 insertions(+), 112 deletions(-)

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 1cb22bfae750..023653977a1a 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -565,7 +565,7 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
 		}
 
 	ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
-						      GFP_KERNEL);
+						     GFP_KERNEL);
 	if (!ubi) {
 		err = -ENOMEM;
 		goto out_mtd;
@@ -583,6 +583,22 @@ static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
 	if (err)
 		goto out_free;
 
+	mutex_init(&ubi->buf_mutex);
+	ubi->peb_buf1 = vmalloc(ubi->peb_size);
+	if (!ubi->peb_buf1)
+		goto out_free;
+
+	ubi->peb_buf2 = vmalloc(ubi->peb_size);
+	if (!ubi->peb_buf2)
+		 goto out_free;
+
+#ifdef CONFIG_MTD_UBI_DEBUG
+	mutex_init(&ubi->dbg_buf_mutex);
+	ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
+	if (!ubi->dbg_peb_buf)
+		 goto out_free;
+#endif
+
 	err = attach_by_scanning(ubi);
 	if (err) {
 		dbg_err("failed to attach by scanning, error %d", err);
@@ -630,6 +646,11 @@ out_detach:
 	ubi_wl_close(ubi);
 	vfree(ubi->vtbl);
 out_free:
+	vfree(ubi->peb_buf1);
+	vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG
+	vfree(ubi->dbg_peb_buf);
+#endif
 	kfree(ubi);
 out_mtd:
 	put_mtd_device(mtd);
@@ -651,6 +672,11 @@ static void detach_mtd_dev(struct ubi_device *ubi)
 	ubi_wl_close(ubi);
 	vfree(ubi->vtbl);
 	put_mtd_device(ubi->mtd);
+	vfree(ubi->peb_buf1);
+	vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG
+	vfree(ubi->dbg_peb_buf);
+#endif
 	kfree(ubi_devices[ubi_num]);
 	ubi_devices[ubi_num] = NULL;
 	ubi_devices_cnt -= 1;
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 89193104c6c8..81bb6a33b555 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -495,16 +495,18 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
 	int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0;
 	struct ubi_volume *vol = ubi->volumes[idx];
 	struct ubi_vid_hdr *vid_hdr;
-	unsigned char *new_buf;
 
 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
 	if (!vid_hdr) {
 		return -ENOMEM;
 	}
 
+	mutex_lock(&ubi->buf_mutex);
+
 retry:
 	new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
 	if (new_pnum < 0) {
+		mutex_unlock(&ubi->buf_mutex);
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		return new_pnum;
 	}
@@ -524,31 +526,22 @@ retry:
 		goto write_error;
 
 	data_size = offset + len;
-	new_buf = vmalloc(data_size);
-	if (!new_buf) {
-		err = -ENOMEM;
-		goto out_put;
-	}
-	memset(new_buf + offset, 0xFF, len);
+	memset(ubi->peb_buf1 + offset, 0xFF, len);
 
 	/* Read everything before the area where the write failure happened */
 	if (offset > 0) {
-		err = ubi_io_read_data(ubi, new_buf, pnum, 0, offset);
-		if (err && err != UBI_IO_BITFLIPS) {
-			vfree(new_buf);
+		err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
+		if (err && err != UBI_IO_BITFLIPS)
 			goto out_put;
-		}
 	}
 
-	memcpy(new_buf + offset, buf, len);
+	memcpy(ubi->peb_buf1 + offset, buf, len);
 
-	err = ubi_io_write_data(ubi, new_buf, new_pnum, 0, data_size);
-	if (err) {
-		vfree(new_buf);
+	err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
+	if (err)
 		goto write_error;
-	}
 
-	vfree(new_buf);
+	mutex_unlock(&ubi->buf_mutex);
 	ubi_free_vid_hdr(ubi, vid_hdr);
 
 	vol->eba_tbl[lnum] = new_pnum;
@@ -558,6 +551,7 @@ retry:
 	return 0;
 
 out_put:
+	mutex_unlock(&ubi->buf_mutex);
 	ubi_wl_put_peb(ubi, new_pnum, 1);
 	ubi_free_vid_hdr(ubi, vid_hdr);
 	return err;
@@ -570,6 +564,7 @@ write_error:
 	ubi_warn("failed to write to PEB %d", new_pnum);
 	ubi_wl_put_peb(ubi, new_pnum, 1);
 	if (++tries > UBI_IO_RETRIES) {
+		mutex_unlock(&ubi->buf_mutex);
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		return err;
 	}
@@ -965,7 +960,6 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	int err, vol_id, lnum, data_size, aldata_size, pnum, idx;
 	struct ubi_volume *vol;
 	uint32_t crc;
-	void *buf, *buf1 = NULL;
 
 	vol_id = be32_to_cpu(vid_hdr->vol_id);
 	lnum = be32_to_cpu(vid_hdr->lnum);
@@ -979,19 +973,15 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 		data_size = aldata_size =
 			    ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);
 
-	buf = vmalloc(aldata_size);
-	if (!buf)
-		return -ENOMEM;
-
 	/*
 	 * We do not want anybody to write to this logical eraseblock while we
 	 * are moving it, so we lock it.
 	 */
 	err = leb_write_lock(ubi, vol_id, lnum);
-	if (err) {
-		vfree(buf);
+	if (err)
 		return err;
-	}
+
+	mutex_lock(&ubi->buf_mutex);
 
 	/*
 	 * But the logical eraseblock might have been put by this time.
@@ -1023,7 +1013,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	/* OK, now the LEB is locked and we can safely start moving it */
 
 	dbg_eba("read %d bytes of data", aldata_size);
-	err = ubi_io_read_data(ubi, buf, from, 0, aldata_size);
+	err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
 	if (err && err != UBI_IO_BITFLIPS) {
 		ubi_warn("error %d while reading data from PEB %d",
 			 err, from);
@@ -1042,10 +1032,10 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	 */
 	if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
 		aldata_size = data_size =
-				ubi_calc_data_len(ubi, buf, data_size);
+			ubi_calc_data_len(ubi, ubi->peb_buf1, data_size);
 
 	cond_resched();
-	crc = crc32(UBI_CRC32_INIT, buf, data_size);
+	crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size);
 	cond_resched();
 
 	/*
@@ -1076,23 +1066,18 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	}
 
 	if (data_size > 0) {
-		err = ubi_io_write_data(ubi, buf, to, 0, aldata_size);
+		err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
 		if (err)
 			goto out_unlock;
 
+		cond_resched();
+
 		/*
 		 * We've written the data and are going to read it back to make
 		 * sure it was written correctly.
 		 */
-		buf1 = vmalloc(aldata_size);
-		if (!buf1) {
-			err = -ENOMEM;
-			goto out_unlock;
-		}
 
-		cond_resched();
-
-		err = ubi_io_read_data(ubi, buf1, to, 0, aldata_size);
+		err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
 		if (err) {
 			if (err != UBI_IO_BITFLIPS)
 				ubi_warn("cannot read data back from PEB %d",
@@ -1102,7 +1087,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 
 		cond_resched();
 
-		if (memcmp(buf, buf1, aldata_size)) {
+		if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
 			ubi_warn("read data back from PEB %d - it is different",
 				 to);
 			goto out_unlock;
@@ -1112,16 +1097,9 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 	ubi_assert(vol->eba_tbl[lnum] == from);
 	vol->eba_tbl[lnum] = to;
 
-	leb_write_unlock(ubi, vol_id, lnum);
-	vfree(buf);
-	vfree(buf1);
-
-	return 0;
-
 out_unlock:
+	mutex_unlock(&ubi->buf_mutex);
 	leb_write_unlock(ubi, vol_id, lnum);
-	vfree(buf);
-	vfree(buf1);
 	return err;
 }
 
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index ba5bc4a5379e..52476d884c48 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -98,8 +98,8 @@ static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
 static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
 static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
 				  const struct ubi_vid_hdr *vid_hdr);
-static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum,
-				 int offset, int len);
+static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
+				 int len);
 #else
 #define paranoid_check_not_bad(ubi, pnum) 0
 #define paranoid_check_peb_ec_hdr(ubi, pnum)  0
@@ -202,8 +202,8 @@ retry:
  * Note, in case of an error, it is possible that something was still written
  * to the flash media, but may be some garbage.
  */
-int ubi_io_write(const struct ubi_device *ubi, const void *buf, int pnum,
-		 int offset, int len)
+int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
+		 int len)
 {
 	int err;
 	size_t written;
@@ -285,7 +285,7 @@ static void erase_callback(struct erase_info *ei)
  * zero in case of success and a negative error code in case of failure. If
  * %-EIO is returned, the physical eraseblock most probably went bad.
  */
-static int do_sync_erase(const struct ubi_device *ubi, int pnum)
+static int do_sync_erase(struct ubi_device *ubi, int pnum)
 {
 	int err, retries = 0;
 	struct erase_info ei;
@@ -377,29 +377,25 @@ static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
  * test, a positive number of erase operations done if the test was
  * successfully passed, and other negative error codes in case of other errors.
  */
-static int torture_peb(const struct ubi_device *ubi, int pnum)
+static int torture_peb(struct ubi_device *ubi, int pnum)
 {
-	void *buf;
 	int err, i, patt_count;
 
-	buf = vmalloc(ubi->peb_size);
-	if (!buf)
-		return -ENOMEM;
-
 	patt_count = ARRAY_SIZE(patterns);
 	ubi_assert(patt_count > 0);
 
+	mutex_lock(&ubi->buf_mutex);
 	for (i = 0; i < patt_count; i++) {
 		err = do_sync_erase(ubi, pnum);
 		if (err)
 			goto out;
 
 		/* Make sure the PEB contains only 0xFF bytes */
-		err = ubi_io_read(ubi, buf, pnum, 0, ubi->peb_size);
+		err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
 		if (err)
 			goto out;
 
-		err = check_pattern(buf, 0xFF, ubi->peb_size);
+		err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
 		if (err == 0) {
 			ubi_err("erased PEB %d, but a non-0xFF byte found",
 				pnum);
@@ -408,17 +404,17 @@ static int torture_peb(const struct ubi_device *ubi, int pnum)
 		}
 
 		/* Write a pattern and check it */
-		memset(buf, patterns[i], ubi->peb_size);
-		err = ubi_io_write(ubi, buf, pnum, 0, ubi->peb_size);
+		memset(ubi->peb_buf1, patterns[i], ubi->peb_size);
+		err = ubi_io_write(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
 		if (err)
 			goto out;
 
-		memset(buf, ~patterns[i], ubi->peb_size);
-		err = ubi_io_read(ubi, buf, pnum, 0, ubi->peb_size);
+		memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size);
+		err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
 		if (err)
 			goto out;
 
-		err = check_pattern(buf, patterns[i], ubi->peb_size);
+		err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
 		if (err == 0) {
 			ubi_err("pattern %x checking failed for PEB %d",
 				patterns[i], pnum);
@@ -430,6 +426,7 @@ static int torture_peb(const struct ubi_device *ubi, int pnum)
 	err = patt_count;
 
 out:
+	mutex_unlock(&ubi->buf_mutex);
 	if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
 		/*
 		 * If a bit-flip or data integrity error was detected, the test
@@ -440,7 +437,6 @@ out:
 			pnum);
 		err = -EIO;
 	}
-	vfree(buf);
 	return err;
 }
 
@@ -460,7 +456,7 @@ out:
  * codes in case of other errors. Note, %-EIO means that the physical
  * eraseblock is bad.
  */
-int ubi_io_sync_erase(const struct ubi_device *ubi, int pnum, int torture)
+int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
 {
 	int err, ret = 0;
 
@@ -617,7 +613,7 @@ bad:
  * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
  * o a negative error code in case of failure.
  */
-int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 		       struct ubi_ec_hdr *ec_hdr, int verbose)
 {
 	int err, read_err = 0;
@@ -723,7 +719,7 @@ int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum,
  * case of failure. If %-EIO is returned, the physical eraseblock most probably
  * went bad.
  */
-int ubi_io_write_ec_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 			struct ubi_ec_hdr *ec_hdr)
 {
 	int err;
@@ -889,7 +885,7 @@ bad:
  *   header there);
  * o a negative error code in case of failure.
  */
-int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 			struct ubi_vid_hdr *vid_hdr, int verbose)
 {
 	int err, read_err = 0;
@@ -996,7 +992,7 @@ int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum,
  * case of failure. If %-EIO is returned, the physical eraseblock probably went
  * bad.
  */
-int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 			 struct ubi_vid_hdr *vid_hdr)
 {
 	int err;
@@ -1219,44 +1215,40 @@ exit:
  * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
  * code if an error occurred.
  */
-static int paranoid_check_all_ff(const struct ubi_device *ubi, int pnum,
-				 int offset, int len)
+static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
+				 int len)
 {
 	size_t read;
 	int err;
-	void *buf;
 	loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
 
-	buf = vmalloc(len);
-	if (!buf)
-		return -ENOMEM;
-	memset(buf, 0, len);
-
-	err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
+	mutex_lock(&ubi->dbg_buf_mutex);
+	err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
 	if (err && err != -EUCLEAN) {
 		ubi_err("error %d while reading %d bytes from PEB %d:%d, "
 			"read %zd bytes", err, len, pnum, offset, read);
 		goto error;
 	}
 
-	err = check_pattern(buf, 0xFF, len);
+	err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
 	if (err == 0) {
 		ubi_err("flash region at PEB %d:%d, length %d does not "
 			"contain all 0xFF bytes", pnum, offset, len);
 		goto fail;
 	}
+	mutex_unlock(&ubi->dbg_buf_mutex);
 
-	vfree(buf);
 	return 0;
 
 fail:
 	ubi_err("paranoid check failed for PEB %d", pnum);
 	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4,
+		       ubi->dbg_peb_buf, len, 1);
 	err = 1;
 error:
 	ubi_dbg_dump_stack();
-	vfree(buf);
+	mutex_unlock(&ubi->dbg_buf_mutex);
 	return err;
 }
 
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 1c1401d6958b..44d87e8158c6 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -45,8 +45,7 @@
 #include "ubi.h"
 
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-static int paranoid_check_si(const struct ubi_device *ubi,
-			     struct ubi_scan_info *si);
+static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
 #else
 #define paranoid_check_si(ubi, si) 0
 #endif
@@ -259,9 +258,8 @@ static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
  *     o bit 2 is cleared: the older LEB is not corrupted;
  *     o bit 2 is set: the older LEB is corrupted.
  */
-static int compare_lebs(const struct ubi_device *ubi,
-			const struct ubi_scan_leb *seb, int pnum,
-			const struct ubi_vid_hdr *vid_hdr)
+static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
+			int pnum, const struct ubi_vid_hdr *vid_hdr)
 {
 	void *buf;
 	int len, err, second_is_newer, bitflips = 0, corrupted = 0;
@@ -413,7 +411,7 @@ out_free_vidh:
  * to be picked, while the older one has to be dropped. This function returns
  * zero in case of success and a negative error code in case of failure.
  */
-int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si,
+int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 		      int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 		      int bitflips)
 {
@@ -667,8 +665,8 @@ void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
  * function returns zero in case of success and a negative error code in case
  * of failure.
  */
-int ubi_scan_erase_peb(const struct ubi_device *ubi,
-		       const struct ubi_scan_info *si, int pnum, int ec)
+int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
+		       int pnum, int ec)
 {
 	int err;
 	struct ubi_ec_hdr *ec_hdr;
@@ -712,7 +710,7 @@ out_free:
  * This function returns scanning physical eraseblock information in case of
  * success and an error code in case of failure.
  */
-struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi,
+struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 					   struct ubi_scan_info *si)
 {
 	int err = 0, i;
@@ -1110,8 +1108,7 @@ void ubi_scan_destroy_si(struct ubi_scan_info *si)
  * This function returns zero if the scanning information is all right, %1 if
  * not and a negative error code if an error occurred.
  */
-static int paranoid_check_si(const struct ubi_device *ubi,
-			     struct ubi_scan_info *si)
+static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
 {
 	int pnum, err, vols_found = 0;
 	struct rb_node *rb1, *rb2;
diff --git a/drivers/mtd/ubi/scan.h b/drivers/mtd/ubi/scan.h
index 140e82e26534..46d444af471a 100644
--- a/drivers/mtd/ubi/scan.h
+++ b/drivers/mtd/ubi/scan.h
@@ -147,7 +147,7 @@ static inline void ubi_scan_move_to_list(struct ubi_scan_volume *sv,
 		list_add_tail(&seb->u.list, list);
 }
 
-int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si,
+int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 		      int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 		      int bitflips);
 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
@@ -155,10 +155,10 @@ struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 				       int lnum);
 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv);
-struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi,
+struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 					   struct ubi_scan_info *si);
-int ubi_scan_erase_peb(const struct ubi_device *ubi,
-		       const struct ubi_scan_info *si, int pnum, int ec);
+int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
+		       int pnum, int ec);
 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi);
 void ubi_scan_destroy_si(struct ubi_scan_info *si);
 
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 329663188772..cc010111264f 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -274,6 +274,12 @@ struct ubi_wl_entry;
  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
  * not
  * @mtd: MTD device descriptor
+ *
+ * @peb_buf1: a buffer of PEB size used for different purposes
+ * @peb_buf2: another buffer of PEB size used for different purposes
+ * @buf_mutex: proptects @peb_buf1 and @peb_buf2
+ * @dbg_peb_buf:  buffer of PEB size used for debugging
+ * @dbg_buf_mutex: proptects @dbg_peb_buf
  */
 struct ubi_device {
 	struct cdev cdev;
@@ -343,6 +349,14 @@ struct ubi_device {
 	int vid_hdr_shift;
 	int bad_allowed;
 	struct mtd_info *mtd;
+
+	void *peb_buf1;
+	void *peb_buf2;
+	struct mutex buf_mutex;
+#ifdef CONFIG_MTD_UBI_DEBUG
+	void *dbg_peb_buf;
+	struct mutex dbg_buf_mutex;
+#endif
 };
 
 extern struct file_operations ubi_cdev_operations;
@@ -409,18 +423,18 @@ void ubi_wl_close(struct ubi_device *ubi);
 /* io.c */
 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 		int len);
-int ubi_io_write(const struct ubi_device *ubi, const void *buf, int pnum,
-		 int offset, int len);
-int ubi_io_sync_erase(const struct ubi_device *ubi, int pnum, int torture);
+int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
+		 int len);
+int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
-int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 		       struct ubi_ec_hdr *ec_hdr, int verbose);
-int ubi_io_write_ec_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 			struct ubi_ec_hdr *ec_hdr);
-int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 			struct ubi_vid_hdr *vid_hdr, int verbose);
-int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum,
+int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 			 struct ubi_vid_hdr *vid_hdr);
 
 /*
@@ -494,7 +508,7 @@ static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
  * the beginning of the logical eraseblock, not to the beginning of the
  * physical eraseblock.
  */
-static inline int ubi_io_write_data(const struct ubi_device *ubi, const void *buf,
+static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 				    int pnum, int offset, int len)
 {
 	ubi_assert(offset >= 0);
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index b0a1e8426456..25b3bd61c7ec 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -254,7 +254,7 @@ bad:
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-static int create_vtbl(const struct ubi_device *ubi, struct ubi_scan_info *si,
+static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
 		       int copy, void *vtbl)
 {
 	int err, tries = 0;
@@ -339,7 +339,7 @@ out_free:
  * not corrupted, and recovering from corruptions if needed. Returns volume
  * table in case of success and a negative error code in case of failure.
  */
-static struct ubi_vtbl_record *process_lvol(const struct ubi_device *ubi,
+static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi,
 					    struct ubi_scan_info *si,
 					    struct ubi_scan_volume *sv)
 {
@@ -453,7 +453,7 @@ out_free:
  * This function returns volume table contents in case of success and a
  * negative error code in case of failure.
  */
-static struct ubi_vtbl_record *create_empty_lvol(const struct ubi_device *ubi,
+static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi,
 						 struct ubi_scan_info *si)
 {
 	int i;
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 248ff9e477e7..6e5315bf5e1b 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -208,7 +208,7 @@ struct ubi_work {
 };
 
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
-static int paranoid_check_ec(const struct ubi_device *ubi, int pnum, int ec);
+static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec);
 static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
 				     struct rb_root *root);
 #else
@@ -1625,7 +1625,7 @@ void ubi_wl_close(struct ubi_device *ubi)
  * is equivalent to @ec, %1 if not, and a negative error code if an error
  * occurred.
  */
-static int paranoid_check_ec(const struct ubi_device *ubi, int pnum, int ec)
+static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec)
 {
 	int err;
 	long long read_ec;

From 6986646ba752fef150286926aa922ef04e9d19dd Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Wed, 29 Aug 2007 14:56:20 +0300
Subject: [PATCH 08/15] UBI: use byte hexdump

More handy since word hexdump prints in host endian.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/debug.c | 4 ++--
 drivers/mtd/ubi/io.c    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 785137435185..56956ec2845f 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -42,8 +42,8 @@ void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
 	dbg_msg("data_offset    %d",    be32_to_cpu(ec_hdr->data_offset));
 	dbg_msg("hdr_crc        %#08x", be32_to_cpu(ec_hdr->hdr_crc));
 	dbg_msg("erase counter header hexdump:");
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4,
-		       (void *)ec_hdr, UBI_EC_HDR_SIZE, 1);
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		       ec_hdr, UBI_EC_HDR_SIZE, 1);
 }
 
 /**
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 52476d884c48..7c304eec78b5 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -1243,7 +1243,7 @@ static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
 fail:
 	ubi_err("paranoid check failed for PEB %d", pnum);
 	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
-	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4,
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 		       ubi->dbg_peb_buf, len, 1);
 	err = 1;
 error:

From e8823bd63d50bb1f9bd73f1197230e1f7217456a Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Thu, 13 Sep 2007 14:28:14 +0300
Subject: [PATCH 09/15] UBI: fix atomic LEB change problems

When the UBI device is nearly full, i.e. all LEBs are mapped, we have
only one spare LEB left - the one we reserved for WL purposes. Well,
I do not count the LEBs which were reserved for bad PEB handling -
suppose NOR flash for simplicity. If an "atomic LEB change operation"
is run, and the WL unit is moving a LEB, we have no spare LEBs to
finish the operation and fail, which is not good. Moreover, if there
are 2 or more simultanious "atomic LEB change" requests, only one of
them has chances to succeed, the other will fail with -ENOSPC. Not
good either.

This patch does 2 things:
1. Reserves one PEB for the "atomic LEB change" operation.
2. Serealize the operations so that only on of them may run
   at a time (by means of a mutex).

Pointed-to-by: Brijesh Singh <brijesh.s.singh@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/eba.c | 48 ++++++++++++++++++++++++++-----------------
 drivers/mtd/ubi/ubi.h |  6 ++++--
 2 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 81bb6a33b555..7b7add6da12f 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -46,6 +46,9 @@
 #include <linux/err.h>
 #include "ubi.h"
 
+/* Number of physical eraseblocks reserved for atomic LEB change operation */
+#define EBA_RESERVED_PEBS 1
+
 /**
  * struct ltree_entry - an entry in the lock tree.
  * @rb: links RB-tree nodes
@@ -827,6 +830,9 @@ write_error:
  * data, which has to be aligned. This function guarantees that in case of an
  * unclean reboot the old contents is preserved. Returns zero in case of
  * success and a negative error code in case of failure.
+ *
+ * UBI reserves one LEB for the "atomic LEB change" operation, so only one
+ * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
  */
 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
 			      const void *buf, int len, int dtype)
@@ -843,11 +849,10 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
 	if (!vid_hdr)
 		return -ENOMEM;
 
+	mutex_lock(&ubi->alc_mutex);
 	err = leb_write_lock(ubi, vol_id, lnum);
-	if (err) {
-		ubi_free_vid_hdr(ubi, vid_hdr);
-		return err;
-	}
+	if (err)
+		goto out_mutex;
 
 	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
 	vid_hdr->vol_id = cpu_to_be32(vol_id);
@@ -864,9 +869,8 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
 retry:
 	pnum = ubi_wl_get_peb(ubi, dtype);
 	if (pnum < 0) {
-		ubi_free_vid_hdr(ubi, vid_hdr);
-		leb_write_unlock(ubi, vol_id, lnum);
-		return pnum;
+		err = pnum;
+		goto out_leb_unlock;
 	}
 
 	dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
@@ -888,17 +892,18 @@ retry:
 
 	if (vol->eba_tbl[lnum] >= 0) {
 		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
-		if (err) {
-			ubi_free_vid_hdr(ubi, vid_hdr);
-			leb_write_unlock(ubi, vol_id, lnum);
-			return err;
-		}
+		if (err)
+			goto out_leb_unlock;
 	}
 
 	vol->eba_tbl[lnum] = pnum;
+
+out_leb_unlock:
 	leb_write_unlock(ubi, vol_id, lnum);
+out_mutex:
+	mutex_unlock(&ubi->alc_mutex);
 	ubi_free_vid_hdr(ubi, vid_hdr);
-	return 0;
+	return err;
 
 write_error:
 	if (err != -EIO || !ubi->bad_allowed) {
@@ -908,17 +913,13 @@ write_error:
 		 * mode just in case.
 		 */
 		ubi_ro_mode(ubi);
-		leb_write_unlock(ubi, vol_id, lnum);
-		ubi_free_vid_hdr(ubi, vid_hdr);
-		return err;
+		goto out_leb_unlock;
 	}
 
 	err = ubi_wl_put_peb(ubi, pnum, 1);
 	if (err || ++tries > UBI_IO_RETRIES) {
 		ubi_ro_mode(ubi);
-		leb_write_unlock(ubi, vol_id, lnum);
-		ubi_free_vid_hdr(ubi, vid_hdr);
-		return err;
+		goto out_leb_unlock;
 	}
 
 	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
@@ -1122,6 +1123,7 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	dbg_eba("initialize EBA unit");
 
 	spin_lock_init(&ubi->ltree_lock);
+	mutex_init(&ubi->alc_mutex);
 	ubi->ltree = RB_ROOT;
 
 	if (ubi_devices_cnt == 0) {
@@ -1183,6 +1185,14 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
 	}
 
+	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
+		ubi_err("no enough physical eraseblocks (%d, need %d)",
+			ubi->avail_pebs, EBA_RESERVED_PEBS);
+		goto out_free;
+	}
+	ubi->avail_pebs -= EBA_RESERVED_PEBS;
+	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
+
 	dbg_eba("EBA unit is initialized");
 	return 0;
 
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index cc010111264f..5e941a633030 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -221,14 +221,15 @@ struct ubi_wl_entry;
  * @vtbl_slots: how many slots are available in the volume table
  * @vtbl_size: size of the volume table in bytes
  * @vtbl: in-RAM volume table copy
+ * @vtbl_mutex: protects on-flash volume table
  *
  * @max_ec: current highest erase counter value
  * @mean_ec: current mean erase counter value
  *
- * global_sqnum: global sequence number
+ * @global_sqnum: global sequence number
  * @ltree_lock: protects the lock tree and @global_sqnum
  * @ltree: the lock tree
- * @vtbl_mutex: protects on-flash volume table
+ * @alc_mutex: serializes "atomic LEB change" operations
  *
  * @used: RB-tree of used physical eraseblocks
  * @free: RB-tree of free physical eraseblocks
@@ -308,6 +309,7 @@ struct ubi_device {
 	unsigned long long global_sqnum;
 	spinlock_t ltree_lock;
 	struct rb_root ltree;
+	struct mutex alc_mutex;
 
 	/* Wear-leveling unit's stuff */
 	struct rb_root used;

From 5abde384e350e44e9d0584238b9ee327f2062f93 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Thu, 13 Sep 2007 14:48:20 +0300
Subject: [PATCH 10/15] UBI: remove useless inlines

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/wl.c | 119 ++++++++++++++-----------------------------
 1 file changed, 38 insertions(+), 81 deletions(-)

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 6e5315bf5e1b..a4f1bf33164a 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -219,17 +219,6 @@ static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
 /* Slab cache for wear-leveling entries */
 static struct kmem_cache *wl_entries_slab;
 
-/**
- * tree_empty - a helper function to check if an RB-tree is empty.
- * @root: the root of the tree
- *
- * This function returns non-zero if the RB-tree is empty and zero if not.
- */
-static inline int tree_empty(struct rb_root *root)
-{
-	return root->rb_node == NULL;
-}
-
 /**
  * wl_tree_add - add a wear-leveling entry to a WL RB-tree.
  * @e: the wear-leveling entry to add
@@ -266,45 +255,6 @@ static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root)
 	rb_insert_color(&e->rb, root);
 }
 
-
-/*
- * Helper functions to add and delete wear-leveling entries from different
- * trees.
- */
-
-static void free_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e)
-{
-	wl_tree_add(e, &ubi->free);
-}
-static inline void used_tree_add(struct ubi_device *ubi,
-				 struct ubi_wl_entry *e)
-{
-	wl_tree_add(e, &ubi->used);
-}
-static inline void scrub_tree_add(struct ubi_device *ubi,
-				  struct ubi_wl_entry *e)
-{
-	wl_tree_add(e, &ubi->scrub);
-}
-static inline void free_tree_del(struct ubi_device *ubi,
-				 struct ubi_wl_entry *e)
-{
-	paranoid_check_in_wl_tree(e, &ubi->free);
-	rb_erase(&e->rb, &ubi->free);
-}
-static inline void used_tree_del(struct ubi_device *ubi,
-				 struct ubi_wl_entry *e)
-{
-	paranoid_check_in_wl_tree(e, &ubi->used);
-	rb_erase(&e->rb, &ubi->used);
-}
-static inline void scrub_tree_del(struct ubi_device *ubi,
-				  struct ubi_wl_entry *e)
-{
-	paranoid_check_in_wl_tree(e, &ubi->scrub);
-	rb_erase(&e->rb, &ubi->scrub);
-}
-
 /**
  * do_work - do one pending work.
  * @ubi: UBI device description object
@@ -358,7 +308,7 @@ static int produce_free_peb(struct ubi_device *ubi)
 	int err;
 
 	spin_lock(&ubi->wl_lock);
-	while (tree_empty(&ubi->free)) {
+	while (!ubi->free.rb_node) {
 		spin_unlock(&ubi->wl_lock);
 
 		dbg_wl("do one work synchronously");
@@ -514,7 +464,7 @@ int ubi_wl_get_peb(struct ubi_device *ubi, int dtype)
 
 retry:
 	spin_lock(&ubi->wl_lock);
-	if (tree_empty(&ubi->free)) {
+	if (!ubi->free.rb_node) {
 		if (ubi->works_count == 0) {
 			ubi_assert(list_empty(&ubi->works));
 			ubi_err("no free eraseblocks");
@@ -585,7 +535,8 @@ retry:
 	 * Move the physical eraseblock to the protection trees where it will
 	 * be protected from being moved for some time.
 	 */
-	free_tree_del(ubi, e);
+	paranoid_check_in_wl_tree(e, &ubi->free);
+	rb_erase(&e->rb, &ubi->free);
 	prot_tree_add(ubi, e, pe, protect);
 
 	dbg_wl("PEB %d EC %d, protection %d", e->pnum, e->ec, protect);
@@ -704,7 +655,7 @@ static void check_protection_over(struct ubi_device *ubi)
 	 */
 	while (1) {
 		spin_lock(&ubi->wl_lock);
-		if (tree_empty(&ubi->prot.aec)) {
+		if (!ubi->prot.aec.rb_node) {
 			spin_unlock(&ubi->wl_lock);
 			break;
 		}
@@ -721,7 +672,7 @@ static void check_protection_over(struct ubi_device *ubi)
 		       pe->e->pnum, ubi->abs_ec, pe->abs_ec);
 		rb_erase(&pe->rb_aec, &ubi->prot.aec);
 		rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
-		used_tree_add(ubi, pe->e);
+		wl_tree_add(pe->e, &ubi->used);
 		spin_unlock(&ubi->wl_lock);
 
 		kfree(pe);
@@ -812,8 +763,8 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 	 * Only one WL worker at a time is supported at this implementation, so
 	 * make sure a PEB is not being moved already.
 	 */
-	if (ubi->move_to || tree_empty(&ubi->free) ||
-	    (tree_empty(&ubi->used) && tree_empty(&ubi->scrub))) {
+	if (ubi->move_to || !ubi->free.rb_node ||
+	    (!ubi->used.rb_node && !ubi->scrub.rb_node)) {
 		/*
 		 * Only one WL worker at a time is supported at this
 		 * implementation, so if a LEB is already being moved, cancel.
@@ -828,14 +779,14 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 		 * triggered again.
 		 */
 		dbg_wl("cancel WL, a list is empty: free %d, used %d",
-		       tree_empty(&ubi->free), tree_empty(&ubi->used));
+		       !ubi->free.rb_node, !ubi->used.rb_node);
 		ubi->wl_scheduled = 0;
 		spin_unlock(&ubi->wl_lock);
 		ubi_free_vid_hdr(ubi, vid_hdr);
 		return 0;
 	}
 
-	if (tree_empty(&ubi->scrub)) {
+	if (!ubi->scrub.rb_node) {
 		/*
 		 * Now pick the least worn-out used physical eraseblock and a
 		 * highly worn-out free physical eraseblock. If the erase
@@ -852,17 +803,20 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			ubi_free_vid_hdr(ubi, vid_hdr);
 			return 0;
 		}
-		used_tree_del(ubi, e1);
+		paranoid_check_in_wl_tree(e1, &ubi->used);
+		rb_erase(&e1->rb, &ubi->used);
 		dbg_wl("move PEB %d EC %d to PEB %d EC %d",
 		       e1->pnum, e1->ec, e2->pnum, e2->ec);
 	} else {
 		e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, rb);
 		e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
-		scrub_tree_del(ubi, e1);
+		paranoid_check_in_wl_tree(e1, &ubi->scrub);
+	rb_erase(&e1->rb, &ubi->scrub);
 		dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum);
 	}
 
-	free_tree_del(ubi, e2);
+	paranoid_check_in_wl_tree(e2, &ubi->free);
+	rb_erase(&e2->rb, &ubi->free);
 	ubi_assert(!ubi->move_from && !ubi->move_to);
 	ubi_assert(!ubi->move_to_put && !ubi->move_from_put);
 	ubi->move_from = e1;
@@ -908,7 +862,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 	ubi_free_vid_hdr(ubi, vid_hdr);
 	spin_lock(&ubi->wl_lock);
 	if (!ubi->move_to_put)
-		used_tree_add(ubi, e2);
+		wl_tree_add(e2, &ubi->used);
 	else
 		put = 1;
 	ubi->move_from = ubi->move_to = NULL;
@@ -953,7 +907,7 @@ error:
 	if (ubi->move_from_put)
 		put = 1;
 	else
-		used_tree_add(ubi, e1);
+		wl_tree_add(e1, &ubi->used);
 	ubi->move_from = ubi->move_to = NULL;
 	ubi->move_from_put = ubi->move_to_put = 0;
 	spin_unlock(&ubi->wl_lock);
@@ -1005,8 +959,8 @@ static int ensure_wear_leveling(struct ubi_device *ubi)
 	 * If the ubi->scrub tree is not empty, scrubbing is needed, and the
 	 * the WL worker has to be scheduled anyway.
 	 */
-	if (tree_empty(&ubi->scrub)) {
-		if (tree_empty(&ubi->used) || tree_empty(&ubi->free))
+	if (!ubi->scrub.rb_node) {
+		if (!ubi->used.rb_node || !ubi->free.rb_node)
 			/* No physical eraseblocks - no deal */
 			goto out_unlock;
 
@@ -1079,7 +1033,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
 
 		spin_lock(&ubi->wl_lock);
 		ubi->abs_ec += 1;
-		free_tree_add(ubi, e);
+		wl_tree_add(e, &ubi->free);
 		spin_unlock(&ubi->wl_lock);
 
 		/*
@@ -1212,11 +1166,13 @@ int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture)
 		spin_unlock(&ubi->wl_lock);
 		return 0;
 	} else {
-		if (in_wl_tree(e, &ubi->used))
-			used_tree_del(ubi, e);
-		else if (in_wl_tree(e, &ubi->scrub))
-			scrub_tree_del(ubi, e);
-		else
+		if (in_wl_tree(e, &ubi->used)) {
+			paranoid_check_in_wl_tree(e, &ubi->used);
+			rb_erase(&e->rb, &ubi->used);
+		} else if (in_wl_tree(e, &ubi->scrub)) {
+			paranoid_check_in_wl_tree(e, &ubi->scrub);
+			rb_erase(&e->rb, &ubi->scrub);
+		} else
 			prot_tree_del(ubi, e->pnum);
 	}
 	spin_unlock(&ubi->wl_lock);
@@ -1224,7 +1180,7 @@ int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture)
 	err = schedule_erase(ubi, e, torture);
 	if (err) {
 		spin_lock(&ubi->wl_lock);
-		used_tree_add(ubi, e);
+		wl_tree_add(e, &ubi->used);
 		spin_unlock(&ubi->wl_lock);
 	}
 
@@ -1268,12 +1224,13 @@ retry:
 		goto retry;
 	}
 
-	if (in_wl_tree(e, &ubi->used))
-		used_tree_del(ubi, e);
-	else
+	if (in_wl_tree(e, &ubi->used)) {
+		paranoid_check_in_wl_tree(e, &ubi->used);
+		rb_erase(&e->rb, &ubi->used);
+	} else
 		prot_tree_del(ubi, pnum);
 
-	scrub_tree_add(ubi, e);
+	wl_tree_add(e, &ubi->scrub);
 	spin_unlock(&ubi->wl_lock);
 
 	/*
@@ -1489,7 +1446,7 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 		e->pnum = seb->pnum;
 		e->ec = seb->ec;
 		ubi_assert(e->ec >= 0);
-		free_tree_add(ubi, e);
+		wl_tree_add(e, &ubi->free);
 		ubi->lookuptbl[e->pnum] = e;
 	}
 
@@ -1523,16 +1480,16 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 			if (!seb->scrub) {
 				dbg_wl("add PEB %d EC %d to the used tree",
 				       e->pnum, e->ec);
-				used_tree_add(ubi, e);
+				wl_tree_add(e, &ubi->used);
 			} else {
 				dbg_wl("add PEB %d EC %d to the scrub tree",
 				       e->pnum, e->ec);
-				scrub_tree_add(ubi, e);
+				wl_tree_add(e, &ubi->scrub);
 			}
 		}
 	}
 
-	if (WL_RESERVED_PEBS > ubi->avail_pebs) {
+	if (ubi->avail_pebs < WL_RESERVED_PEBS) {
 		ubi_err("no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, WL_RESERVED_PEBS);
 		goto out_free;

From cc5f4f28755b3b152297fd7bc3e03781dd8008e2 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Sun, 14 Oct 2007 13:01:58 +0300
Subject: [PATCH 11/15] UBI: return correct error code

Fix the following warning:

drivers/mtd/ubi/eba.c: In function 'ubi_eba_init_scan':
drivers/mtd/ubi/eba.c:1116: warning: 'err' may be used uninitialized in this function

Pointed-to-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/eba.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 7b7add6da12f..1297732f4db9 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -1188,6 +1188,7 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
 		ubi_err("no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, EBA_RESERVED_PEBS);
+		err = -ENOSPC;
 		goto out_free;
 	}
 	ubi->avail_pebs -= EBA_RESERVED_PEBS;

From 34627f0e768de6af95e3523c29a16cbb95ce3197 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <ext-adrian.hunter@nokia.com>
Date: Fri, 12 Oct 2007 10:19:26 +0300
Subject: [PATCH 12/15] [MTD] [OneNAND] Synchronize block locking operations

Ensure OneNAND's block locking operations are synchronized
like all other operations.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
 drivers/mtd/onenand/onenand_base.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index b2c40f67db83..f633941011a5 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -1904,7 +1904,12 @@ static int onenand_do_lock_cmd(struct mtd_info *mtd, loff_t ofs, size_t len, int
  */
 static int onenand_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
 {
-	return onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_LOCK);
+	int ret;
+
+	onenand_get_device(mtd, FL_LOCKING);
+	ret = onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_LOCK);
+	onenand_release_device(mtd);
+	return ret;
 }
 
 /**
@@ -1917,7 +1922,12 @@ static int onenand_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
  */
 static int onenand_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
 {
-	return onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
+	int ret;
+
+	onenand_get_device(mtd, FL_LOCKING);
+	ret = onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
+	onenand_release_device(mtd);
+	return ret;
 }
 
 /**
@@ -1979,7 +1989,7 @@ static int onenand_unlock_all(struct mtd_info *mtd)
 			loff_t ofs = this->chipsize >> 1;
 			size_t len = mtd->erasesize;
 
-			onenand_unlock(mtd, ofs, len);
+			onenand_do_lock_cmd(mtd, ofs, len, ONENAND_CMD_UNLOCK);
 		}
 
 		onenand_check_lock_status(this);
@@ -1987,7 +1997,7 @@ static int onenand_unlock_all(struct mtd_info *mtd)
 		return 0;
 	}
 
-	onenand_unlock(mtd, 0x0, this->chipsize);
+	onenand_do_lock_cmd(mtd, 0x0, this->chipsize, ONENAND_CMD_UNLOCK);
 
 	return 0;
 }

From 30a7eb298af849bae3050e0a3f4c130995da22b0 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <ext-adrian.hunter@nokia.com>
Date: Fri, 12 Oct 2007 10:19:38 +0300
Subject: [PATCH 13/15] [MTD] [OneNAND] Return only negative error codes

The OneNAND driver was confusing JFFS2 by returning positive error
codes.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
 drivers/mtd/onenand/onenand_base.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index f633941011a5..a8c426bf47a4 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -327,7 +327,7 @@ static int onenand_wait(struct mtd_info *mtd, int state)
 		printk(KERN_ERR "onenand_wait: controller error = 0x%04x\n", ctrl);
 		if (ctrl & ONENAND_CTRL_LOCK)
 			printk(KERN_ERR "onenand_wait: it's locked error.\n");
-		return ctrl;
+		return -EIO;
 	}
 
 	if (interrupt & ONENAND_INT_READ) {
@@ -336,7 +336,7 @@ static int onenand_wait(struct mtd_info *mtd, int state)
 			if (ecc & ONENAND_ECC_2BIT_ALL) {
 				printk(KERN_ERR "onenand_wait: ECC error = 0x%04x\n", ecc);
 				mtd->ecc_stats.failed++;
-				return ecc;
+				return -EBADMSG;
 			} else if (ecc & ONENAND_ECC_1BIT_ALL) {
 				printk(KERN_INFO "onenand_wait: correctable ECC error = 0x%04x\n", ecc);
 				mtd->ecc_stats.corrected++;

From 3cd3a86b6fdcb80ad097850a0990bcf6251422fe Mon Sep 17 00:00:00 2001
From: Adrian Hunter <ext-adrian.hunter@nokia.com>
Date: Fri, 12 Oct 2007 10:34:01 +0300
Subject: [PATCH 14/15] [MTD] [OneNAND] Avoid deadlock in erase callback;
 release chip lock first.

When the erase callback performs some other action on the flash, it's
highly likely to deadlock unless we actually release the chip lock
before calling it.

This patch mirrors that same change already done for NAND.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
 drivers/mtd/onenand/onenand_base.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index a8c426bf47a4..dd2835569092 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -1711,13 +1711,14 @@ static int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
 erase_exit:
 
 	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
-	/* Do call back function */
-	if (!ret)
-		mtd_erase_callback(instr);
 
 	/* Deselect and wake up anyone waiting on the device */
 	onenand_release_device(mtd);
 
+	/* Do call back function */
+	if (!ret)
+		mtd_erase_callback(instr);
+
 	return ret;
 }
 

From a2e1b833d9e0231d67e722b7e2f4d79daf919baf Mon Sep 17 00:00:00 2001
From: Chris Paulson-Ellis <chris@edesix.com>
Date: Fri, 12 Oct 2007 10:54:06 +0100
Subject: [PATCH 15/15] [MTD] fix mtdconcat for subpage-write NAND

This allows the mtdconcat driver to work with NAND flash devices that
support sub-page writes.

Signed-off-by: Chris Paulson-Ellis <chris@edesix.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
 drivers/mtd/mtdconcat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 96be7ef62f35..d563dcd4b264 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -726,6 +726,7 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],	/* subdevices to c
 	concat->mtd.size = subdev[0]->size;
 	concat->mtd.erasesize = subdev[0]->erasesize;
 	concat->mtd.writesize = subdev[0]->writesize;
+	concat->mtd.subpage_sft = subdev[0]->subpage_sft;
 	concat->mtd.oobsize = subdev[0]->oobsize;
 	concat->mtd.oobavail = subdev[0]->oobavail;
 	if (subdev[0]->writev)