Anton Salikhmetov wrote:
From: Anton Salikhmetov <[EMAIL PROTECTED]>
The patch contains changes for updating the ctime and mtime fields for memory
mapped files:
1) adding a new flag triggering update of the inode data;
2) implementing a helper function for checking that flag and updating ctime and
mtime;
3) updating time stamps for mapped files in sys_msync() and do_fsync().
Sorry, one other issue to throw out too -- an mmap'd block device
should also have its inode time fields updated. This is a little
tricky because the inode referenced via mapping->host isn't the
one that needs to have the time fields updated on.
I have attached the patch that I submitted last. It is quite out
of date, but does show my attempt to resolve some of these issues.
Thanx...
ps
--- linux-2.6.20.i686/fs/buffer.c.org
+++ linux-2.6.20.i686/fs/buffer.c
@@ -710,6 +710,7 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
int __set_page_dirty_buffers(struct page *page)
{
struct address_space * const mapping = page_mapping(page);
+ int ret = 0;
if (unlikely(!mapping))
return !TestSetPageDirty(page);
@@ -727,7 +728,7 @@ int __set_page_dirty_buffers(struct page
spin_unlock(&mapping->private_lock);
if (TestSetPageDirty(page))
- return 0;
+ goto out;
write_lock_irq(&mapping->tree_lock);
if (page->mapping) { /* Race with truncate? */
@@ -740,7 +741,11 @@ int __set_page_dirty_buffers(struct page
}
write_unlock_irq(&mapping->tree_lock);
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
- return 1;
+ ret = 1;
+out:
+ if (page_mapped(page))
+ set_bit(AS_MCTIME, &mapping->flags);
+ return ret;
}
EXPORT_SYMBOL(__set_page_dirty_buffers);
--- linux-2.6.20.i686/fs/fs-writeback.c.org
+++ linux-2.6.20.i686/fs/fs-writeback.c
@@ -167,6 +167,13 @@ __sync_single_inode(struct inode *inode,
spin_unlock(&inode_lock);
+ if (test_and_clear_bit(AS_MCTIME, &mapping->flags)) {
+ if (S_ISBLK(inode->i_mode))
+ bd_inode_update_time(inode);
+ else
+ inode_update_time(inode);
+ }
+
ret = do_writepages(mapping, wbc);
/* Don't write the inode if only I_DIRTY_PAGES was set */
--- linux-2.6.20.i686/fs/inode.c.org
+++ linux-2.6.20.i686/fs/inode.c
@@ -1201,8 +1201,8 @@ void touch_atime(struct vfsmount *mnt, s
EXPORT_SYMBOL(touch_atime);
/**
- * file_update_time - update mtime and ctime time
- * @file: file accessed
+ * inode_update_time - update mtime and ctime time
+ * @inode: file accessed
*
* Update the mtime and ctime members of an inode and mark the inode
* for writeback. Note that this function is meant exclusively for
@@ -1212,9 +1212,8 @@ EXPORT_SYMBOL(touch_atime);
* timestamps are handled by the server.
*/
-void file_update_time(struct file *file)
+void inode_update_time(struct inode *inode)
{
- struct inode *inode = file->f_path.dentry->d_inode;
struct timespec now;
int sync_it = 0;
@@ -1238,7 +1237,7 @@ void file_update_time(struct file *file)
mark_inode_dirty_sync(inode);
}
-EXPORT_SYMBOL(file_update_time);
+EXPORT_SYMBOL(inode_update_time);
int inode_needs_sync(struct inode *inode)
{
--- linux-2.6.20.i686/fs/block_dev.c.org
+++ linux-2.6.20.i686/fs/block_dev.c
@@ -608,6 +608,22 @@ void bdput(struct block_device *bdev)
EXPORT_SYMBOL(bdput);
+void bd_inode_update_time(struct inode *inode)
+{
+ struct block_device *bdev = inode->i_bdev;
+ struct list_head *p;
+
+ if (bdev == NULL)
+ return;
+
+ spin_lock(&bdev_lock);
+ list_for_each(p, &bdev->bd_inodes) {
+ inode = list_entry(p, struct inode, i_devices);
+ inode_update_time(inode);
+ }
+ spin_unlock(&bdev_lock);
+}
+
static struct block_device *bd_acquire(struct inode *inode)
{
struct block_device *bdev;
--- linux-2.6.20.i686/include/linux/fs.h.org
+++ linux-2.6.20.i686/include/linux/fs.h
@@ -1488,6 +1488,7 @@ extern struct block_device *bdget(dev_t)
extern void bd_set_size(struct block_device *, loff_t size);
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
+extern void bd_inode_update_time(struct inode *);
extern struct block_device *open_by_devnum(dev_t, unsigned);
extern const struct address_space_operations def_blk_aops;
#else
@@ -1892,7 +1893,11 @@ extern int buffer_migrate_page(struct ad
extern int inode_change_ok(struct inode *, struct iattr *);
extern int __must_check inode_setattr(struct inode *, struct iattr *);
-extern void file_update_time(struct file *file);
+extern void inode_update_time(struct inode *inode);
+static inline void file_update_time(struct file *file)
+{
+ inode_update_time(file->f_path.dentry->d_inode);
+}
static inline ino_t parent_ino(struct dentry *dentry)
{
--- linux-2.6.20.i686/include/linux/pagemap.h.org
+++ linux-2.6.20.i686/include/linux/pagemap.h
@@ -16,8 +16,9 @@
* Bits in mapping->flags. The lower __GFP_BITS_SHIFT bits are the page
* allocation mode flags.
*/
-#define AS_EIO (__GFP_BITS_SHIFT + 0) /* IO error on async
write */
+#define AS_EIO (__GFP_BITS_SHIFT + 0) /* IO error on async write */
#define AS_ENOSPC (__GFP_BITS_SHIFT + 1) /* ENOSPC on async write */
+#define AS_MCTIME (__GFP_BITS_SHIFT + 2) /* need m/ctime change */
static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
{
--- linux-2.6.20.i686/mm/page-writeback.c.org
+++ linux-2.6.20.i686/mm/page-writeback.c
@@ -760,8 +760,10 @@ int __set_page_dirty_no_writeback(struct
*/
int __set_page_dirty_nobuffers(struct page *page)
{
+ struct address_space *mapping = page_mapping(page);
+ int ret = 0;
+
if (!TestSetPageDirty(page)) {
- struct address_space *mapping = page_mapping(page);
struct address_space *mapping2;
if (!mapping)
@@ -783,9 +785,11 @@ int __set_page_dirty_nobuffers(struct pa
/* !PageAnon && !swapper_space */
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
- return 1;
+ ret = 1;
}
- return 0;
+ if (page_mapped(page))
+ set_bit(AS_MCTIME, &mapping->flags);
+ return ret;
}
EXPORT_SYMBOL(__set_page_dirty_nobuffers);
--- linux-2.6.20.i686/mm/msync.c.org
+++ linux-2.6.20.i686/mm/msync.c
@@ -12,6 +12,7 @@
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/syscalls.h>
+#include <linux/pagemap.h>
/*
* MS_SYNC syncs the entire file - including mappings.
@@ -77,11 +78,16 @@ asmlinkage long sys_msync(unsigned long
}
file = vma->vm_file;
start = vma->vm_end;
- if ((flags & MS_SYNC) && file &&
- (vma->vm_flags & VM_SHARED)) {
+ if ((flags & (MS_SYNC|MS_ASYNC)) &&
+ file && (vma->vm_flags & VM_SHARED)) {
get_file(file);
up_read(&mm->mmap_sem);
- error = do_fsync(file, 0);
+ error = 0;
+ if (flags & MS_SYNC)
+ error = do_fsync(file, 0);
+ else if (test_and_clear_bit(AS_MCTIME,
+ &file->f_mapping->flags))
+ file_update_time(file);
fput(file);
if (error || start >= end)
goto out;
