VFS: Add 64 bit inode version support From: Jean Noel Cordenner The i_version field of the inode is changed to be a 64-bit counter that is set on every inode creation and that is incremented every time the inode data is modified (similarly to the "ctime" time-stamp). The aim is to fulfill a NFSv4 requirement for rfc3530. This first part concerns the vfs, it converts the 32-bit i_version in the generic inode to a 64-bit, a flag is added in the super block in order to check if the feature is enabled and the i_version is incremented in the vfs. Signed-off-by: Mingming Cao Signed-off-by: Jean Noel Cordenner Signed-off-by: Kalpak Shah --- fs/inode.c | 22 ++++++++++++++++++++++ include/linux/fs.h | 5 ++++- 2 files changed, 26 insertions(+), 1 deletion(-) Index: linux-2.6.24-rc3/include/linux/fs.h =================================================================== --- linux-2.6.24-rc3.orig/include/linux/fs.h 2007-11-20 17:11:39.000000000 -0800 +++ linux-2.6.24-rc3/include/linux/fs.h 2007-11-20 17:15:24.000000000 -0800 @@ -124,6 +124,7 @@ extern int dir_notify_enable; #define MS_SHARED (1<<20) /* change to shared */ #define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */ #define MS_KERNMOUNT (1<<22) /* this is a kern_mount call */ +#define MS_I_VERSION (1<<23) /* Update inode I_version field */ #define MS_ACTIVE (1<<30) #define MS_NOUSER (1<<31) @@ -173,6 +174,7 @@ extern int dir_notify_enable; ((inode)->i_flags & (S_SYNC|S_DIRSYNC))) #define IS_MANDLOCK(inode) __IS_FLG(inode, MS_MANDLOCK) #define IS_NOATIME(inode) __IS_FLG(inode, MS_RDONLY|MS_NOATIME) +#define IS_I_VERSION(inode) __IS_FLG(inode, MS_I_VERSION) #define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA) #define IS_APPEND(inode) ((inode)->i_flags & S_APPEND) @@ -599,7 +601,7 @@ struct inode { uid_t i_uid; gid_t i_gid; dev_t i_rdev; - unsigned long i_version; + u64 i_version; loff_t i_size; #ifdef __NEED_I_SIZE_ORDERED seqcount_t i_size_seqcount; @@ -1394,6 +1396,7 @@ static inline void inode_dec_link_count( mark_inode_dirty(inode); } +extern void inode_inc_iversion(struct inode *inode); extern void touch_atime(struct vfsmount *mnt, struct dentry *dentry); static inline void file_accessed(struct file *file) { Index: linux-2.6.24-rc3/fs/inode.c =================================================================== --- linux-2.6.24-rc3.orig/fs/inode.c 2007-11-16 21:16:36.000000000 -0800 +++ linux-2.6.24-rc3/fs/inode.c 2007-11-20 17:12:52.000000000 -0800 @@ -1243,6 +1243,23 @@ void touch_atime(struct vfsmount *mnt, s EXPORT_SYMBOL(touch_atime); /** + * inode_inc_iversion - increments i_version + * @inode: inode that need to be updated + * + * Every time the inode is modified, the i_version field + * will be incremented. + * The filesystem has to be mounted with i_version flag + * + */ + +void inode_inc_iversion(struct inode *inode) +{ + spin_lock(&inode->i_lock); + inode->i_version++; + spin_unlock(&inode->i_lock); +} + +/** * file_update_time - update mtime and ctime time * @file: file accessed * @@ -1276,6 +1293,11 @@ void file_update_time(struct file *file) sync_it = 1; } + if (IS_I_VERSION(inode)) { + inode_inc_iversion(inode); + sync_it = 1; + } + if (sync_it) mark_inode_dirty_sync(inode); }