From: Maxim Levitsky <maximlevitsky@gmail.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>,
linux-mtd <linux-mtd@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Alex Dubov <oakad@yahoo.com>, joern <joern@logfs.org>,
Thomas Gleixner <tglx@linutronix.de>,
Maxim Levitsky <maximlevitsky@gmail.com>
Subject: [PATCH 01/17] MTD: create lockless versions of {get,put}_mtd_device This will be used to resolve deadlock in block translation layer.
Date: Sat, 30 Jan 2010 17:02:32 +0200 [thread overview]
Message-ID: <1264863768-27606-2-git-send-email-maximlevitsky@gmail.com> (raw)
In-Reply-To: <1264863768-27606-1-git-send-email-maximlevitsky@gmail.com>
These functions can be used as long as we don't need access to global mtd table, but have
a pointer to the mtd device.
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
drivers/mtd/mtdcore.c | 60 ++++++++++++++++++++++++++++++----------------
include/linux/mtd/mtd.h | 3 +-
2 files changed, 41 insertions(+), 22 deletions(-)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index c356c0a..3bdb7e8 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -453,27 +453,38 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
ret = NULL;
}
- if (!ret)
- goto out_unlock;
-
- if (!try_module_get(ret->owner))
- goto out_unlock;
-
- if (ret->get_device) {
- err = ret->get_device(ret);
- if (err)
- goto out_put;
+ if (!ret) {
+ ret = ERR_PTR(err);
+ goto out;
}
- ret->usecount++;
+ err = __get_mtd_device(ret);
+ if (err)
+ ret = ERR_PTR(err);
+out:
mutex_unlock(&mtd_table_mutex);
return ret;
+}
-out_put:
- module_put(ret->owner);
-out_unlock:
- mutex_unlock(&mtd_table_mutex);
- return ERR_PTR(err);
+
+int __get_mtd_device(struct mtd_info *mtd)
+{
+ int err;
+
+ if (!try_module_get(mtd->owner))
+ return -ENODEV;
+
+ if (mtd->get_device) {
+
+ err = mtd->get_device(mtd);
+
+ if (err) {
+ module_put(mtd->owner);
+ return err;
+ }
+ }
+ mtd->usecount++;
+ return 0;
}
/**
@@ -524,14 +535,19 @@ out_unlock:
void put_mtd_device(struct mtd_info *mtd)
{
- int c;
-
mutex_lock(&mtd_table_mutex);
- c = --mtd->usecount;
+ __put_mtd_device(mtd);
+ mutex_unlock(&mtd_table_mutex);
+
+}
+
+void __put_mtd_device(struct mtd_info *mtd)
+{
+ --mtd->usecount;
+ BUG_ON(mtd->usecount < 0);
+
if (mtd->put_device)
mtd->put_device(mtd);
- mutex_unlock(&mtd_table_mutex);
- BUG_ON(c < 0);
module_put(mtd->owner);
}
@@ -569,7 +585,9 @@ EXPORT_SYMBOL_GPL(add_mtd_device);
EXPORT_SYMBOL_GPL(del_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
+EXPORT_SYMBOL_GPL(__get_mtd_device);
EXPORT_SYMBOL_GPL(put_mtd_device);
+EXPORT_SYMBOL_GPL(__put_mtd_device);
EXPORT_SYMBOL_GPL(register_mtd_user);
EXPORT_SYMBOL_GPL(unregister_mtd_user);
EXPORT_SYMBOL_GPL(default_mtd_writev);
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 0f32a9b..662d747 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -290,8 +290,9 @@ extern int add_mtd_device(struct mtd_info *mtd);
extern int del_mtd_device (struct mtd_info *mtd);
extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
+extern int __get_mtd_device(struct mtd_info *mtd);
+extern void __put_mtd_device(struct mtd_info *mtd);
extern struct mtd_info *get_mtd_device_nm(const char *name);
-
extern void put_mtd_device(struct mtd_info *mtd);
--
1.6.3.3
next prev parent reply other threads:[~2010-01-30 15:06 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-30 15:02 [PATCH V5] Work to enable SmartMedia/xD support Maxim Levitsky
2010-01-30 15:02 ` Maxim Levitsky [this message]
2010-01-30 15:02 ` [PATCH 02/17] blktrans: nuke mtd_blkcore_priv and make both thread and disk queue be per device Maxim Levitsky
2010-01-30 15:02 ` [PATCH 03/17] blktrans: track open and close calls Maxim Levitsky
2010-02-01 7:46 ` Ricard Wanderlof
2010-02-01 15:40 ` Maxim Levitsky
2010-01-30 15:02 ` [PATCH 04/17] blktrans: don't free mtd_blktrans_dev, core will do that for you Maxim Levitsky
2010-01-30 15:02 ` [PATCH 05/17] blktrans: add proper locking Maxim Levitsky
2010-01-30 15:02 ` [PATCH 06/17] blktrans: flush all requests before we remove the device Maxim Levitsky
2010-01-30 15:02 ` [PATCH 07/17] blktrans: allow FTL drivers to export sysfs attributes Maxim Levitsky
2010-01-30 15:02 ` [PATCH 08/17] MTD: call remove notifiers before removing the device Maxim Levitsky
2010-01-30 15:02 ` [PATCH 09/17] MTD: nand: make MTD_OOB_PLACE work correctly Maxim Levitsky
2010-01-30 15:02 ` [PATCH 10/17] MTD: nand: make reads using MTD_OOB_RAW affect only ECC validation Maxim Levitsky
2010-01-30 15:02 ` [PATCH 11/17] MTD: nand: fix bug that prevented write of more that one page by ->write_oob Maxim Levitsky
2010-01-30 15:02 ` [PATCH 12/17] MTD: nand: make suspend work if device is accessed by kernel threads Maxim Levitsky
2010-01-30 15:02 ` [PATCH 13/17] MTD: export few functions from nand_base.c Maxim Levitsky
2010-01-30 15:02 ` [PATCH 14/17] MTD: common module for smartmedia/xD support Maxim Levitsky
2010-01-30 15:02 ` [PATCH 15/17] MTD: add few workarounds to nand system for SmartMedia/xD chips Maxim Levitsky
2010-01-30 15:02 ` [PATCH 16/17] MTD: Add nand driver for ricoh xD/SmartMedia reader Maxim Levitsky
2010-01-30 15:02 ` [PATCH 17/17] MTD: Add new SmartMedia/xD FTL Maxim Levitsky
2010-01-30 15:25 ` [PATCH] " Maxim Levitsky
-- strict thread matches above, loose matches on Subject: below --
2010-02-04 23:30 [PATCH V6] Work to enable SmartMedia/xD support Maxim Levitsky
2010-02-04 23:30 ` [PATCH 01/17] MTD: create lockless versions of {get,put}_mtd_device This will be used to resolve deadlock in block translation layer Maxim Levitsky
2010-02-09 16:57 [PATCH 0/17 V7] Work to enable SmartMedia/xD support in mtd subsystem Maxim Levitsky
2010-02-09 16:57 ` [PATCH 01/17] MTD: create lockless versions of {get,put}_mtd_device This will be used to resolve deadlock in block translation layer Maxim Levitsky
2010-02-09 17:14 ` Peter Zijlstra
2010-02-09 17:23 ` Maxim Levitsky
2010-02-09 17:46 ` Maxim Levitsky
2010-02-10 21:22 ` Maxim Levitsky
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