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From: Arnd Bergmann <arnd@arndb.de>
To: linux-kernel@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH 14/15] vfs: don't use BKL in default_llseek
Date: Tue, 14 Sep 2010 22:22:42 +0200	[thread overview]
Message-ID: <1284495763-7506-15-git-send-email-arnd@arndb.de> (raw)
In-Reply-To: <1284495763-7506-1-git-send-email-arnd@arndb.de>

There are currently 191 users of default_llseek.
Nine of these are in device drivers that use the
big kernel lock. None of these ever touch
file->f_pos outside of llseek or file_pos_write.

Consequently, we never rely on the BKL
in the default_llseek function and can
replace that with i_mutex, which is also
used in generic_file_llseek.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/read_write.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 74e3658..fd09f61 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -124,7 +124,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
 {
 	loff_t retval;
 
-	lock_kernel();
+	mutex_lock(&file->f_dentry->d_inode->i_mutex);
 	switch (origin) {
 		case SEEK_END:
 			offset += i_size_read(file->f_path.dentry->d_inode);
@@ -145,7 +145,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
 		retval = offset;
 	}
 out:
-	unlock_kernel();
+	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
 	return retval;
 }
 EXPORT_SYMBOL(default_llseek);
-- 
1.7.1


  parent reply	other threads:[~2010-09-14 20:23 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-14 20:22 [PATCH 00/15] change default_llseek action Arnd Bergmann
2010-09-14 20:22 ` [PATCH 01/15] drm: use noop_llseek Arnd Bergmann
2010-09-14 20:22 ` [PATCH 02/15] net/wireless: use generic_file_llseek in debugfs Arnd Bergmann
2010-09-14 20:22 ` [PATCH 03/15] lkdtm: " Arnd Bergmann
2010-09-14 20:22 ` [PATCH 04/15] arm/omap: use generic_file_llseek in iommu_debug Arnd Bergmann
2010-09-14 20:22 ` [PATCH 05/15] spufs: use llseek in all file operations Arnd Bergmann
2010-09-14 20:22 ` [PATCH 06/15] ibmasmfs: use generic_file_llseek Arnd Bergmann
2010-09-14 20:22 ` [PATCH 07/15] raw: use explicit llseek file operations Arnd Bergmann
2010-09-14 20:22 ` [PATCH 08/15] irda/irnet: use noop_llseek Arnd Bergmann
2010-09-16  2:31   ` David Miller
2010-09-14 20:22 ` [PATCH 09/15] viotape: " Arnd Bergmann
2010-09-14 20:22 ` [PATCH 10/15] lirc: make chardev nonseekable Arnd Bergmann
2010-09-14 20:22 ` [PATCH 11/15] mac80211: disallow seeks in minstrel debug code Arnd Bergmann
2010-09-14 20:22 ` [PATCH 12/15] libfs: use generic_file_llseek for simple_attr Arnd Bergmann
2010-09-14 20:22 ` [PATCH 13/15] llseek: automatically add .llseek fop Arnd Bergmann
2010-09-14 20:22 ` Arnd Bergmann [this message]
2010-09-14 20:22 ` [PATCH 15/15] vfs: make no_llseek the default Arnd Bergmann
2010-09-15  9:39 ` [PATCH 00/15] change default_llseek action Stephen Rothwell
2010-09-15 16:06   ` Luis R. Rodriguez
2010-09-15 15:38 ` Valdis.Kletnieks
2010-09-15 16:37   ` Arnd Bergmann

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