[XFS] add a FMODE flag to make XFS invisible I/O less hacky

XFS has a mode called invisble I/O that doesn't update any of the
timestamps.  It's used for HSM-style applications and exposed through
the nasty open by handle ioctl.

Instead of doing directly assignment of file operations that set an
internal flag for it add a new FMODE_NOCMTIME flag that we can check
in the normal file operations.

(addition of the generic VFS flag has been ACKed by Al as an interims
 solution)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

7 files changed, 71 insertions, 178 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index f999d20a429c..a0c45cc8a6b8 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -45,81 +45,45 @@
 
 static struct vm_operations_struct xfs_file_vm_ops;
 
-STATIC_INLINE ssize_t
-__xfs_file_read(
+STATIC ssize_t
+xfs_file_aio_read(
         struct kiocb            *iocb,
         const struct iovec      *iov,
         unsigned long           nr_segs,
-        int                     ioflags,
         loff_t                  pos)
 {
         struct file             *file = iocb->ki_filp;
+        int                     ioflags = IO_ISAIO;
 
         BUG_ON(iocb->ki_pos != pos);
         if (unlikely(file->f_flags & O_DIRECT))
                 ioflags |= IO_ISDIRECT;
+        if (file->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
         return xfs_read(XFS_I(file->f_path.dentry->d_inode), iocb, iov,
                                 nr_segs, &iocb->ki_pos, ioflags);
 }
 
 STATIC ssize_t
-xfs_file_aio_read(
-        struct kiocb            *iocb,
-        const struct iovec      *iov,
-        unsigned long           nr_segs,
-        loff_t                  pos)
-{
-        return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO, pos);
-}
-
-STATIC ssize_t
-xfs_file_aio_read_invis(
-        struct kiocb            *iocb,
-        const struct iovec      *iov,
-        unsigned long           nr_segs,
-        loff_t                  pos)
-{
-        return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
-}
-
-STATIC_INLINE ssize_t
-__xfs_file_write(
+xfs_file_aio_write(
         struct kiocb            *iocb,
         const struct iovec      *iov,
         unsigned long           nr_segs,
-        int                     ioflags,
         loff_t                  pos)
 {
-        struct file     *file = iocb->ki_filp;
+        struct file             *file = iocb->ki_filp;
+        int                     ioflags = IO_ISAIO;
 
         BUG_ON(iocb->ki_pos != pos);
         if (unlikely(file->f_flags & O_DIRECT))
                 ioflags |= IO_ISDIRECT;
+        if (file->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
         return xfs_write(XFS_I(file->f_mapping->host), iocb, iov, nr_segs,
                                 &iocb->ki_pos, ioflags);
 }
 
 STATIC ssize_t
-xfs_file_aio_write(
-        struct kiocb            *iocb,
-        const struct iovec      *iov,
-        unsigned long           nr_segs,
-        loff_t                  pos)
-{
-        return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO, pos);
-}
-
-STATIC ssize_t
-xfs_file_aio_write_invis(
-        struct kiocb            *iocb,
-        const struct iovec      *iov,
-        unsigned long           nr_segs,
-        loff_t                  pos)
-{
-        return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
-}
-
-STATIC ssize_t
 xfs_file_splice_read(
         struct file             *infilp,
         loff_t                  *ppos,
@@ -127,20 +91,13 @@ xfs_file_splice_read(
         size_t                  len,
         unsigned int            flags)
 {
-        return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
-                                   infilp, ppos, pipe, len, flags, 0);
-}
+        int                     ioflags = 0;
+
+        if (infilp->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
 
-STATIC ssize_t
-xfs_file_splice_read_invis(
-        struct file             *infilp,
-        loff_t                  *ppos,
-        struct pipe_inode_info  *pipe,
-        size_t                  len,
-        unsigned int            flags)
-{
         return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
-                                   infilp, ppos, pipe, len, flags, IO_INVIS);
+                                   infilp, ppos, pipe, len, flags, ioflags);
 }
 
 STATIC ssize_t
@@ -151,20 +108,13 @@ xfs_file_splice_write(
         size_t                  len,
         unsigned int            flags)
 {
-        return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
-                                    pipe, outfilp, ppos, len, flags, 0);
-}
+        int                     ioflags = 0;
+
+        if (outfilp->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
 
-STATIC ssize_t
-xfs_file_splice_write_invis(
-        struct pipe_inode_info  *pipe,
-        struct file             *outfilp,
-        loff_t                  *ppos,
-        size_t                  len,
-        unsigned int            flags)
-{
         return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
-                                    pipe, outfilp, ppos, len, flags, IO_INVIS);
+                                    pipe, outfilp, ppos, len, flags, ioflags);
 }
 
 STATIC int
@@ -275,42 +225,6 @@ xfs_file_mmap(
         return 0;
 }
 
-STATIC long
-xfs_file_ioctl(
-        struct file     *filp,
-        unsigned int    cmd,
-        unsigned long   p)
-{
-        struct inode    *inode = filp->f_path.dentry->d_inode;
-
-
-        /* NOTE:  some of the ioctl's return positive #'s as a
-         *        byte count indicating success, such as
-         *        readlink_by_handle.  So we don't "sign flip"
-         *        like most other routines.  This means true
-         *        errors need to be returned as a negative value.
-         */
-        return xfs_ioctl(XFS_I(inode), filp, 0, cmd, (void __user *)p);
-}
-
-STATIC long
-xfs_file_ioctl_invis(
-        struct file     *filp,
-        unsigned int    cmd,
-        unsigned long   p)
-{
-        struct inode    *inode = filp->f_path.dentry->d_inode;
-
-
-        /* NOTE:  some of the ioctl's return positive #'s as a
-         *        byte count indicating success, such as
-         *        readlink_by_handle.  So we don't "sign flip"
-         *        like most other routines.  This means true
-         *        errors need to be returned as a negative value.
-         */
-        return xfs_ioctl(XFS_I(inode), filp, IO_INVIS, cmd, (void __user *)p);
-}
-
 /*
  * mmap()d file has taken write protection fault and is being made
  * writable. We can set the page state up correctly for a writable
@@ -346,25 +260,6 @@ const struct file_operations xfs_file_operations = {
 #endif
 };
 
-const struct file_operations xfs_invis_file_operations = {
-        .llseek         = generic_file_llseek,
-        .read           = do_sync_read,
-        .write          = do_sync_write,
-        .aio_read       = xfs_file_aio_read_invis,
-        .aio_write      = xfs_file_aio_write_invis,
-        .splice_read    = xfs_file_splice_read_invis,
-        .splice_write   = xfs_file_splice_write_invis,
-        .unlocked_ioctl = xfs_file_ioctl_invis,
-#ifdef CONFIG_COMPAT
-        .compat_ioctl   = xfs_file_compat_invis_ioctl,
-#endif
-        .mmap           = xfs_file_mmap,
-        .open           = xfs_file_open,
-        .release        = xfs_file_release,
-        .fsync          = xfs_file_fsync,
-};
-
-
 const struct file_operations xfs_dir_file_operations = {
         .open           = xfs_dir_open,
         .read           = generic_read_dir,
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index c8f1e632ba94..0264c8719ffd 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -319,10 +319,11 @@ xfs_open_by_handle(
                 put_unused_fd(new_fd);
                 return -XFS_ERROR(-PTR_ERR(filp));
         }
+
         if (inode->i_mode & S_IFREG) {
                 /* invisible operation should not change atime */
                 filp->f_flags |= O_NOATIME;
-                filp->f_op = &xfs_invis_file_operations;
+                filp->f_mode |= FMODE_NOCMTIME;
         }
 
         fd_install(new_fd, filp);
@@ -1328,21 +1329,31 @@ xfs_ioc_getbmapx(
         return 0;
 }
 
-int
-xfs_ioctl(
-        xfs_inode_t             *ip,
+/*
+ * Note: some of the ioctl's return positive numbers as a
+ * byte count indicating success, such as readlink_by_handle.
+ * So we don't "sign flip" like most other routines.  This means
+ * true errors need to be returned as a negative value.
+ */
+long
+xfs_file_ioctl(
         struct file             *filp,
-        int                     ioflags,
         unsigned int            cmd,
-        void                    __user *arg)
+        unsigned long           p)
 {
         struct inode            *inode = filp->f_path.dentry->d_inode;
-        xfs_mount_t             *mp = ip->i_mount;
+        struct xfs_inode        *ip = XFS_I(inode);
+        struct xfs_mount        *mp = ip->i_mount;
+        void                    __user *arg = (void __user *)p;
+        int                     ioflags = 0;
         int                     error;
 
-        xfs_itrace_entry(XFS_I(inode));
-        switch (cmd) {
+        if (filp->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
 
+        xfs_itrace_entry(ip);
+
+        switch (cmd) {
         case XFS_IOC_ALLOCSP:
         case XFS_IOC_FREESP:
         case XFS_IOC_RESVSP:
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.h b/fs/xfs/linux-2.6/xfs_ioctl.h
index d92131c827bc..8c16bf2d7e03 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.h
+++ b/fs/xfs/linux-2.6/xfs_ioctl.h
@@ -68,13 +68,13 @@ xfs_attrmulti_attr_remove(
         __uint32_t              flags);
 
 extern long
-xfs_file_compat_ioctl(
-        struct file             *file,
+xfs_file_ioctl(
+        struct file             *filp,
         unsigned int            cmd,
-        unsigned long           arg);
+        unsigned long           p);
 
 extern long
-xfs_file_compat_invis_ioctl(
+xfs_file_compat_ioctl(
         struct file             *file,
         unsigned int            cmd,
         unsigned long           arg);
diff --git a/fs/xfs/linux-2.6/xfs_ioctl32.c b/fs/xfs/linux-2.6/xfs_ioctl32.c
index b34b3d8892a2..0504cece9f66 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl32.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl32.c
@@ -599,19 +599,24 @@ out:
         return error;
 }
 
-STATIC long
-xfs_compat_ioctl(
-        xfs_inode_t     *ip,
-        struct file     *filp,
-        int             ioflags,
-        unsigned        cmd,
-        void            __user *arg)
+long
+xfs_file_compat_ioctl(
+        struct file             *filp,
+        unsigned                cmd,
+        unsigned long           p)
 {
-        struct inode    *inode = filp->f_path.dentry->d_inode;
-        xfs_mount_t     *mp = ip->i_mount;
-        int             error;
+        struct inode            *inode = filp->f_path.dentry->d_inode;
+        struct xfs_inode        *ip = XFS_I(inode);
+        struct xfs_mount        *mp = ip->i_mount;
+        void                    __user *arg = (void __user *)p;
+        int                     ioflags = 0;
+        int                     error;
+
+        if (filp->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
+
+        xfs_itrace_entry(ip);
 
-        xfs_itrace_entry(XFS_I(inode));
         switch (cmd) {
         /* No size or alignment issues on any arch */
         case XFS_IOC_DIOINFO:
@@ -632,7 +637,7 @@ xfs_compat_ioctl(
         case XFS_IOC_GOINGDOWN:
         case XFS_IOC_ERROR_INJECTION:
         case XFS_IOC_ERROR_CLEARALL:
-                return xfs_ioctl(ip, filp, ioflags, cmd, arg);
+                return xfs_file_ioctl(filp, cmd, p);
 #ifndef BROKEN_X86_ALIGNMENT
         /* These are handled fine if no alignment issues */
         case XFS_IOC_ALLOCSP:
@@ -646,7 +651,7 @@ xfs_compat_ioctl(
         case XFS_IOC_FSGEOMETRY_V1:
         case XFS_IOC_FSGROWFSDATA:
         case XFS_IOC_FSGROWFSRT:
-                return xfs_ioctl(ip, filp, ioflags, cmd, arg);
+                return xfs_file_ioctl(filp, cmd, p);
 #else
         case XFS_IOC_ALLOCSP_32:
         case XFS_IOC_FREESP_32:
@@ -687,7 +692,7 @@ xfs_compat_ioctl(
         case XFS_IOC_SETXFLAGS_32:
         case XFS_IOC_GETVERSION_32:
                 cmd = _NATIVE_IOC(cmd, long);
-                return xfs_ioctl(ip, filp, ioflags, cmd, arg);
+                return xfs_file_ioctl(filp, cmd, p);
         case XFS_IOC_SWAPEXT: {
                 struct xfs_swapext        sxp;
                 struct compat_xfs_swapext __user *sxu = arg;
@@ -738,26 +743,3 @@ xfs_compat_ioctl(
                 return -XFS_ERROR(ENOIOCTLCMD);
         }
 }
-
-long
-xfs_file_compat_ioctl(
-        struct file             *filp,
-        unsigned int            cmd,
-        unsigned long           p)
-{
-        struct inode    *inode = filp->f_path.dentry->d_inode;
-
-        return xfs_compat_ioctl(XFS_I(inode), filp, 0, cmd, (void __user *)p);
-}
-
-long
-xfs_file_compat_invis_ioctl(
-        struct file             *filp,
-        unsigned int            cmd,
-        unsigned long           p)
-{
-        struct inode    *inode = filp->f_path.dentry->d_inode;
-
-        return xfs_compat_ioctl(XFS_I(inode), filp, IO_INVIS, cmd,
-                                (void __user *)p);
-}
diff --git a/fs/xfs/linux-2.6/xfs_iops.h b/fs/xfs/linux-2.6/xfs_iops.h
index 8b1a1e31dc21..ef41c92ce66e 100644
--- a/fs/xfs/linux-2.6/xfs_iops.h
+++ b/fs/xfs/linux-2.6/xfs_iops.h
@@ -22,7 +22,6 @@ struct xfs_inode;
 
 extern const struct file_operations xfs_file_operations;
 extern const struct file_operations xfs_dir_file_operations;
-extern const struct file_operations xfs_invis_file_operations;
 
 extern ssize_t xfs_vn_listxattr(struct dentry *, char *data, size_t size);
 
diff --git a/fs/xfs/xfs_vnodeops.h b/fs/xfs/xfs_vnodeops.h
index 2a45b00ad32e..55d955ec4ece 100644
--- a/fs/xfs/xfs_vnodeops.h
+++ b/fs/xfs/xfs_vnodeops.h
@@ -53,8 +53,6 @@ int xfs_attr_set(struct xfs_inode *dp, const char *name, char *value,
 int xfs_attr_remove(struct xfs_inode *dp, const char *name, int flags);
 int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
                 int flags, struct attrlist_cursor_kern *cursor);
-int xfs_ioctl(struct xfs_inode *ip, struct file *filp,
-                int ioflags, unsigned int cmd, void __user *arg);
 ssize_t xfs_read(struct xfs_inode *ip, struct kiocb *iocb,
                 const struct iovec *iovp, unsigned int segs,
                 loff_t *offset, int ioflags);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 51bd9370d437..965b9ba3865d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -81,6 +81,14 @@ extern int dir_notify_enable;
 #define FMODE_WRITE_IOCTL       ((__force fmode_t)128)
 #define FMODE_NDELAY_NOW        ((__force fmode_t)256)
 
+/*
+ * Don't update ctime and mtime.
+ *
+ * Currently a special hack for the XFS open_by_handle ioctl, but we'll
+ * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
+ */
+#define FMODE_NOCMTIME          ((__force fmode_t)2048)
+
 #define RW_MASK         1
 #define RWA_MASK        2
 #define READ 0