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Date: Sat, 13 Apr 2013 12:35:54 +0200
From: Marco Stornelli <marco.stornelli@...il.com>
To: Linux FS Devel <linux-fsdevel@...r.kernel.org>
CC: Linux Kernel <linux-kernel@...r.kernel.org>,
Jan Kara <jack@...e.cz>, Al Viro <viro@...IV.linux.org.uk>
Subject: [PATCH 1/3] fsfreeze: wait in killable state in __sb_start_write
Added a new enum to decide if we want to sleep in uninterruptible or
killable state or we want simply to return immediately.
Signed-off-by: Marco Stornelli <marco.stornelli@...il.com>
---
fs/super.c | 24 ++++++++++++++++++------
include/linux/fs.h | 19 +++++++++++++------
2 files changed, 31 insertions(+), 12 deletions(-)
diff --git a/fs/super.c b/fs/super.c
index 7465d43..6b70c7f 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1190,14 +1190,25 @@ static void acquire_freeze_lock(struct super_block *sb, int level, bool trylock,
* This is an internal function, please use sb_start_{write,pagefault,intwrite}
* instead.
*/
-int __sb_start_write(struct super_block *sb, int level, bool wait)
+int __sb_start_write(struct super_block *sb, int level, int wait)
{
+ int ret = 0;
retry:
if (unlikely(sb->s_writers.frozen >= level)) {
- if (!wait)
- return 0;
- wait_event(sb->s_writers.wait_unfrozen,
- sb->s_writers.frozen < level);
+ switch (wait) {
+ case FREEZE_NOWAIT:
+ return ret;
+ case FREEZE_WAIT:
+ wait_event(sb->s_writers.wait_unfrozen,
+ sb->s_writers.frozen < level);
+ break;
+ case FREEZE_WAIT_KILLABLE:
+ ret = wait_event_killable(sb->s_writers.wait_unfrozen,
+ sb->s_writers.frozen < level);
+ if (ret)
+ return -EINTR;
+ break;
+ }
}
#ifdef CONFIG_LOCKDEP
@@ -1213,7 +1224,8 @@ retry:
__sb_end_write(sb, level);
goto retry;
}
- return 1;
+ ret = 1;
+ return ret;
}
EXPORT_SYMBOL(__sb_start_write);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8d47c9a..c8b7325 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1220,6 +1220,13 @@ enum {
#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
+/* Possible waiting modes */
+enum {
+ FREEZE_NOWAIT = 0, /* no blocking call */
+ FREEZE_WAIT = 1, /* wait in uninterruptible state */
+ FREEZE_WAIT_KILLABLE = 2, /* wait in killable state */
+};
+
struct sb_writers {
/* Counters for counting writers at each level */
struct percpu_counter counter[SB_FREEZE_LEVELS];
@@ -1335,7 +1342,7 @@ extern struct timespec current_fs_time(struct super_block *sb);
*/
void __sb_end_write(struct super_block *sb, int level);
-int __sb_start_write(struct super_block *sb, int level, bool wait);
+int __sb_start_write(struct super_block *sb, int level, int wait);
/**
* sb_end_write - drop write access to a superblock
@@ -1394,12 +1401,12 @@ static inline void sb_end_intwrite(struct super_block *sb)
*/
static inline void sb_start_write(struct super_block *sb)
{
- __sb_start_write(sb, SB_FREEZE_WRITE, true);
+ __sb_start_write(sb, SB_FREEZE_WRITE, FREEZE_WAIT);
}
static inline int sb_start_write_trylock(struct super_block *sb)
{
- return __sb_start_write(sb, SB_FREEZE_WRITE, false);
+ return __sb_start_write(sb, SB_FREEZE_WRITE, FREEZE_NOWAIT);
}
/**
@@ -1423,7 +1430,7 @@ static inline int sb_start_write_trylock(struct super_block *sb)
*/
static inline void sb_start_pagefault(struct super_block *sb)
{
- __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
+ __sb_start_write(sb, SB_FREEZE_PAGEFAULT, FREEZE_WAIT);
}
/*
@@ -1441,7 +1448,7 @@ static inline void sb_start_pagefault(struct super_block *sb)
*/
static inline void sb_start_intwrite(struct super_block *sb)
{
- __sb_start_write(sb, SB_FREEZE_FS, true);
+ __sb_start_write(sb, SB_FREEZE_FS, FREEZE_WAIT);
}
@@ -2224,7 +2231,7 @@ static inline void file_start_write(struct file *file)
{
if (!S_ISREG(file_inode(file)->i_mode))
return;
- __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+ __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, FREEZE_WAIT);
}
static inline void file_end_write(struct file *file)
--
1.7.3.4
--
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