Ensure no new files will be added when we're inspecting 'all' files. Without
this, files could be added in front while we're iterating and we'd miss those.
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
---
fs/file_table.c | 9 +++++++++
fs/super.c | 3 +++
include/linux/fs.h | 2 ++
security/selinux/selinuxfs.c | 7 ++++---
4 files changed, 18 insertions(+), 3 deletions(-)
Index: linux-2.6/fs/file_table.c
===================================================================
--- linux-2.6.orig/fs/file_table.c 2007-01-27 21:07:44.000000000 +0100
+++ linux-2.6/fs/file_table.c 2007-01-27 21:11:12.000000000 +0100
@@ -354,6 +354,12 @@ EXPORT_SYMBOL_GPL(filevec_add_drain_all)
void file_kill(struct file *file)
{
+ if (file && file->f_mapping && file->f_mapping->host) {
+ struct super_block *sb = file->f_mapping->host->i_sb;
+ if (sb)
+ barrier_sync(&sb->s_barrier);
+ }
+
if (file_flag(file, F_SUPERBLOCK)) {
void **ptr;
@@ -412,6 +418,7 @@ int fs_may_remount_ro(struct super_block
struct file *file;
/* Check that no files are currently opened for writing. */
+ barrier_lock(&sb->s_barrier);
filevec_add_drain_all();
lock_list_for_each_entry(file, &sb->s_files, f_u.fu_llist) {
struct inode *inode = file->f_path.dentry->d_inode;
@@ -424,9 +431,11 @@ int fs_may_remount_ro(struct super_block
if (S_ISREG(inode->i_mode) && (file->f_mode & FMODE_WRITE))
goto too_bad;
}
+ barrier_unlock(&sb->s_barrier);
return 1; /* Tis' cool bro. */
too_bad:
lock_list_for_each_entry_stop(file, f_u.fu_llist);
+ barrier_unlock(&sb->s_barrier);
return 0;
}
Index: linux-2.6/fs/super.c
===================================================================
--- linux-2.6.orig/fs/super.c 2007-01-27 21:07:44.000000000 +0100
+++ linux-2.6/fs/super.c 2007-01-27 21:11:12.000000000 +0100
@@ -68,6 +68,7 @@ static struct super_block *alloc_super(s
INIT_LIST_HEAD(&s->s_dirty);
INIT_LIST_HEAD(&s->s_io);
INIT_LOCK_LIST_HEAD(&s->s_files);
+ init_barrier(&s->s_barrier);
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
@@ -568,11 +569,13 @@ static void mark_files_ro(struct super_b
{
struct file *f;
+ barrier_lock(&sb->s_barrier);
filevec_add_drain_all();
lock_list_for_each_entry(f, &sb->s_files, f_u.fu_llist) {
if (S_ISREG(f->f_path.dentry->d_inode->i_mode) && file_count(f))
f->f_mode &= ~FMODE_WRITE;
}
+ barrier_unlock(&sb->s_barrier);
}
/**
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2007-01-27 21:07:44.000000000 +0100
+++ linux-2.6/include/linux/fs.h 2007-01-27 21:11:12.000000000 +0100
@@ -281,6 +281,7 @@ extern int dir_notify_enable;
#include <linux/init.h>
#include <linux/pid.h>
#include <linux/mutex.h>
+#include <linux/barrier.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
@@ -950,6 +951,7 @@ struct super_block {
struct list_head s_io; /* parked for writeback */
struct hlist_head s_anon; /* anonymous dentries for (nfs)
exporting */
struct lock_list_head s_files;
+ struct barrier s_barrier;
struct block_device *s_bdev;
struct list_head s_instances;
Index: linux-2.6/security/selinux/selinuxfs.c
===================================================================
--- linux-2.6.orig/security/selinux/selinuxfs.c 2007-01-27 21:10:48.000000000
+0100
+++ linux-2.6/security/selinux/selinuxfs.c 2007-01-27 21:11:40.000000000
+0100
@@ -963,6 +963,7 @@ static void sel_remove_bools(struct dent
spin_unlock(&dcache_lock);
+ barrier_lock(&sb->s_barrier);
filevec_add_drain_all();
lock_list_for_each_entry(filp, &sb->s_files, f_u.fu_llist) {
struct dentry * dentry = filp->f_path.dentry;
@@ -972,6 +973,7 @@ static void sel_remove_bools(struct dent
}
filp->f_op = NULL;
}
+ barrier_unlock(&sb->s_barrier);
}
#define BOOL_DIR_NAME "booleans"
--
-
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