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authorValerie Henson <val_henson@linux.intel.com>2006-12-13 00:34:34 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-13 09:05:50 -0800
commit47ae32d6a54955a041cdc30b06d0bb16e75f68d5 (patch)
treeb28623f98ae536342d35443c6548c373df342e7f
parentb227613841d4d211a10c5860acc73e133b613bc0 (diff)
[PATCH] relative atime
Add "relatime" (relative atime) support. Relative atime only updates the atime if the previous atime is older than the mtime or ctime. Like noatime, but useful for applications like mutt that need to know when a file has been read since it was last modified. A corresponding patch against mount(8) is available at http://userweb.kernel.org/~akpm/mount-relative-atime.txt Signed-off-by: Valerie Henson <val_henson@linux.intel.com> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Karel Zak <kzak@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/inode.c22
-rw-r--r--fs/namespace.c5
-rw-r--r--include/linux/fs.h1
-rw-r--r--include/linux/mount.h1
4 files changed, 24 insertions, 5 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 04536ebc5ac..bf21dc6d0db 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1177,13 +1177,27 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
return;
if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
return;
+
+ if (mnt->mnt_flags & MNT_RELATIME) {
+ /*
+ * With relative atime, only update atime if the
+ * previous atime is earlier than either the ctime or
+ * mtime.
+ */
+ if (timespec_compare(&inode->i_mtime,
+ &inode->i_atime) < 0 &&
+ timespec_compare(&inode->i_ctime,
+ &inode->i_atime) < 0)
+ return;
+ }
}
now = current_fs_time(inode->i_sb);
- if (!timespec_equal(&inode->i_atime, &now)) {
- inode->i_atime = now;
- mark_inode_dirty_sync(inode);
- }
+ if (timespec_equal(&inode->i_atime, &now))
+ return;
+
+ inode->i_atime = now;
+ mark_inode_dirty_sync(inode);
}
EXPORT_SYMBOL(touch_atime);
diff --git a/fs/namespace.c b/fs/namespace.c
index fde8553faa7..5ef336c1103 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -368,6 +368,7 @@ static int show_vfsmnt(struct seq_file *m, void *v)
{ MNT_NOEXEC, ",noexec" },
{ MNT_NOATIME, ",noatime" },
{ MNT_NODIRATIME, ",nodiratime" },
+ { MNT_RELATIME, ",relatime" },
{ 0, NULL }
};
struct proc_fs_info *fs_infop;
@@ -1405,9 +1406,11 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
mnt_flags |= MNT_NOATIME;
if (flags & MS_NODIRATIME)
mnt_flags |= MNT_NODIRATIME;
+ if (flags & MS_RELATIME)
+ mnt_flags |= MNT_RELATIME;
flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE |
- MS_NOATIME | MS_NODIRATIME);
+ MS_NOATIME | MS_NODIRATIME | MS_RELATIME);
/* ... and get the mountpoint */
retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index adce6e1d70c..186da813541 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -120,6 +120,7 @@ extern int dir_notify_enable;
#define MS_PRIVATE (1<<18) /* change to private */
#define MS_SLAVE (1<<19) /* change to slave */
#define MS_SHARED (1<<20) /* change to shared */
+#define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */
#define MS_ACTIVE (1<<30)
#define MS_NOUSER (1<<31)
diff --git a/include/linux/mount.h b/include/linux/mount.h
index e357dc86a4d..1b7e178b0d8 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -27,6 +27,7 @@ struct mnt_namespace;
#define MNT_NOEXEC 0x04
#define MNT_NOATIME 0x08
#define MNT_NODIRATIME 0x10
+#define MNT_RELATIME 0x20
#define MNT_SHRINKABLE 0x100