[XFS] Provide XFS support for the splice syscall.

Signed-off-by: Nathan Scott <nathans@sgi.com>

5 files changed, 195 insertions, 62 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 85997b1205f5..ae4c4754ed31 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -69,7 +69,6 @@ __xfs_file_read(
         return rval;
 }
 
-
 STATIC ssize_t
 xfs_file_aio_read(
         struct kiocb            *iocb,
@@ -90,7 +89,6 @@ xfs_file_aio_read_invis(
         return __xfs_file_read(iocb, buf, IO_ISAIO|IO_INVIS, count, pos);
 }
 
-
 STATIC inline ssize_t
 __xfs_file_write(
         struct kiocb    *iocb,
@@ -113,7 +111,6 @@ __xfs_file_write(
         return rval;
 }
 
-
 STATIC ssize_t
 xfs_file_aio_write(
         struct kiocb            *iocb,
@@ -134,7 +131,6 @@ xfs_file_aio_write_invis(
         return __xfs_file_write(iocb, buf, IO_ISAIO|IO_INVIS, count, pos);
 }
 
-
 STATIC inline ssize_t
 __xfs_file_readv(
         struct file             *file,
@@ -179,7 +175,6 @@ xfs_file_readv_invis(
         return __xfs_file_readv(file, iov, IO_INVIS, nr_segs, ppos);
 }
 
-
 STATIC inline ssize_t
 __xfs_file_writev(
         struct file             *file,
@@ -204,7 +199,6 @@ __xfs_file_writev(
         return rval;
 }
 
-
 STATIC ssize_t
 xfs_file_writev(
         struct file             *file,
@@ -228,7 +222,7 @@ xfs_file_writev_invis(
 STATIC ssize_t
 xfs_file_sendfile(
         struct file             *filp,
-        loff_t                  *ppos,
+        loff_t                  *pos,
         size_t                  count,
         read_actor_t            actor,
         void                    *target)
@@ -236,10 +230,80 @@ xfs_file_sendfile(
         vnode_t                 *vp = vn_from_inode(filp->f_dentry->d_inode);
         ssize_t                 rval;
 
-        VOP_SENDFILE(vp, filp, ppos, 0, count, actor, target, NULL, rval);
+        VOP_SENDFILE(vp, filp, pos, 0, count, actor, target, NULL, rval);
         return rval;
 }
 
+STATIC ssize_t
+xfs_file_sendfile_invis(
+        struct file             *filp,
+        loff_t                  *pos,
+        size_t                  count,
+        read_actor_t            actor,
+        void                    *target)
+{
+        vnode_t                 *vp = vn_from_inode(filp->f_dentry->d_inode);
+        ssize_t                 rval;
+
+        VOP_SENDFILE(vp, filp, pos, IO_INVIS, count, actor, target, NULL, rval);
+        return rval;
+}
+
+STATIC ssize_t
+xfs_file_splice_read(
+        struct file             *infilp,
+        struct inode            *pipe,
+        size_t                  len,
+        unsigned int            flags)
+{
+        vnode_t                 *vp = vn_from_inode(infilp->f_dentry->d_inode);
+        ssize_t                 rval;
+
+        VOP_SPLICE_READ(vp, infilp, pipe, len, flags, 0, NULL, rval);
+        return rval;
+}
+
+STATIC ssize_t
+xfs_file_splice_read_invis(
+        struct file             *infilp,
+        struct inode            *pipe,
+        size_t                  len,
+        unsigned int            flags)
+{
+        vnode_t                 *vp = vn_from_inode(infilp->f_dentry->d_inode);
+        ssize_t                 rval;
+
+        VOP_SPLICE_READ(vp, infilp, pipe, len, flags, IO_INVIS, NULL, rval);
+        return rval;
+}
+
+STATIC ssize_t
+xfs_file_splice_write(
+        struct inode            *pipe,
+        struct file             *outfilp,
+        size_t                  len,
+        unsigned int            flags)
+{
+        vnode_t                 *vp = vn_from_inode(outfilp->f_dentry->d_inode);
+        ssize_t                 rval;
+
+        VOP_SPLICE_WRITE(vp, pipe, outfilp, len, flags, 0, NULL, rval);
+        return rval;
+}
+
+STATIC ssize_t
+xfs_file_splice_write_invis(
+        struct inode            *pipe,
+        struct file             *outfilp,
+        size_t                  len,
+        unsigned int            flags)
+{
+        vnode_t                 *vp = vn_from_inode(outfilp->f_dentry->d_inode);
+        ssize_t                 rval;
+
+        VOP_SPLICE_WRITE(vp, pipe, outfilp, len, flags, IO_INVIS, NULL, rval);
+        return rval;
+}
 
 STATIC int
 xfs_file_open(
@@ -251,13 +315,10 @@ xfs_file_open(
 
         if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
                 return -EFBIG;
-
-        ASSERT(vp);
         VOP_OPEN(vp, NULL, error);
         return -error;
 }
 
-
 STATIC int
 xfs_file_release(
         struct inode    *inode,
@@ -271,7 +332,6 @@ xfs_file_release(
         return -error;
 }
 
-
 STATIC int
 xfs_file_fsync(
         struct file     *filp,
@@ -285,21 +345,11 @@ xfs_file_fsync(
 
         if (datasync)
                 flags |= FSYNC_DATA;
-
-        ASSERT(vp);
         VOP_FSYNC(vp, flags, NULL, (xfs_off_t)0, (xfs_off_t)-1, error);
         return -error;
 }
 
-/*
- * xfs_file_readdir maps to VOP_READDIR().
- * We need to build a uio, cred, ...
- */
-
-#define nextdp(dp)      ((struct xfs_dirent *)((char *)(dp) + (dp)->d_reclen))
-
 #ifdef CONFIG_XFS_DMAPI
-
 STATIC struct page *
 xfs_vm_nopage(
         struct vm_area_struct   *area,
@@ -319,10 +369,8 @@ xfs_vm_nopage(
 
         return filemap_nopage(area, address, type);
 }
-
 #endif /* CONFIG_XFS_DMAPI */
 
-
 STATIC int
 xfs_file_readdir(
         struct file     *filp,
@@ -330,7 +378,7 @@ xfs_file_readdir(
         filldir_t       filldir)
 {
         int             error = 0;
-        vnode_t         *vp;
+        vnode_t         *vp = vn_from_inode(filp->f_dentry->d_inode);
         uio_t           uio;
         iovec_t         iov;
         int             eof = 0;
@@ -340,9 +388,6 @@ xfs_file_readdir(
         xfs_off_t       start_offset, curr_offset;
         xfs_dirent_t    *dbp = NULL;
 
-        vp = vn_from_inode(filp->f_dentry->d_inode);
-        ASSERT(vp);
-
         /* Try fairly hard to get memory */
         do {
                 if ((read_buf = (caddr_t)kmalloc(rlen, GFP_KERNEL)))
@@ -387,7 +432,7 @@ xfs_file_readdir(
                         }
                         size -= dbp->d_reclen;
                         curr_offset = (loff_t)dbp->d_off /* & 0x7fffffff */;
-                        dbp = nextdp(dbp);
+                        dbp = (xfs_dirent_t *)((char *)dbp + dbp->d_reclen);
                 }
         }
 done:
@@ -402,7 +447,6 @@ done:
         return -error;
 }
 
-
 STATIC int
 xfs_file_mmap(
         struct file     *filp,
@@ -457,11 +501,10 @@ xfs_file_ioctl_invis(
         unsigned int    cmd,
         unsigned long   arg)
 {
-        int             error;
         struct inode    *inode = filp->f_dentry->d_inode;
         vnode_t         *vp = vn_from_inode(inode);
+        int             error;
 
-        ASSERT(vp);
         VOP_IOCTL(vp, inode, filp, IO_INVIS, cmd, (void __user *)arg, error);
         VMODIFY(vp);
 
@@ -537,6 +580,8 @@ const struct file_operations xfs_file_operations = {
         .aio_read       = xfs_file_aio_read,
         .aio_write      = xfs_file_aio_write,
         .sendfile       = xfs_file_sendfile,
+        .splice_read    = xfs_file_splice_read,
+        .splice_write   = xfs_file_splice_write,
         .unlocked_ioctl = xfs_file_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = xfs_file_compat_ioctl,
@@ -558,7 +603,9 @@ const struct file_operations xfs_invis_file_operations = {
         .writev         = xfs_file_writev_invis,
         .aio_read       = xfs_file_aio_read_invis,
         .aio_write      = xfs_file_aio_write_invis,
-        .sendfile       = xfs_file_sendfile,
+        .sendfile       = xfs_file_sendfile_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,
diff --git a/fs/xfs/linux-2.6/xfs_linux.h b/fs/xfs/linux-2.6/xfs_linux.h
index 1fe09f2d6519..e9fe43d74768 100644
--- a/fs/xfs/linux-2.6/xfs_linux.h
+++ b/fs/xfs/linux-2.6/xfs_linux.h
@@ -103,6 +103,7 @@
  */
 #undef  HAVE_REFCACHE   /* reference cache not needed for NFS in 2.6 */
 #define HAVE_SENDFILE   /* sendfile(2) exists in 2.6, but not in 2.4 */
+#define HAVE_SPLICE     /* a splice(2) exists in 2.6, but not in 2.4 */
 #ifdef CONFIG_SMP
 #define HAVE_PERCPU_SB  /* per cpu superblock counters are a 2.6 feature */
 #else
diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index 84ddf1893894..90cd314acbaa 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -301,36 +301,23 @@ xfs_sendfile(
         void                    *target,
         cred_t                  *credp)
 {
+        xfs_inode_t             *ip = XFS_BHVTOI(bdp);
+        xfs_mount_t             *mp = ip->i_mount;
         ssize_t                 ret;
-        xfs_fsize_t             n;
-        xfs_inode_t             *ip;
-        xfs_mount_t             *mp;
-        vnode_t                 *vp;
-
-        ip = XFS_BHVTOI(bdp);
-        vp = BHV_TO_VNODE(bdp);
-        mp = ip->i_mount;
 
         XFS_STATS_INC(xs_read_calls);
-
-        n = XFS_MAXIOFFSET(mp) - *offset;
-        if ((n <= 0) || (count == 0))
-                return 0;
-
-        if (n < count)
-                count = n;
-
-        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+        if (XFS_FORCED_SHUTDOWN(mp))
                 return -EIO;
 
         xfs_ilock(ip, XFS_IOLOCK_SHARED);
 
-        if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) &&
+        if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
             (!(ioflags & IO_INVIS))) {
                 vrwlock_t locktype = VRWLOCK_READ;
                 int error;
 
-                error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, count,
+                error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
+                                      *offset, count,
                                       FILP_DELAY_FLAG(filp), &locktype);
                 if (error) {
                         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@@ -340,12 +327,96 @@ xfs_sendfile(
         xfs_rw_enter_trace(XFS_SENDFILE_ENTER, &ip->i_iocore,
                    (void *)(unsigned long)target, count, *offset, ioflags);
         ret = generic_file_sendfile(filp, offset, count, actor, target);
+        if (ret > 0)
+                XFS_STATS_ADD(xs_read_bytes, ret);
 
         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+        return ret;
+}
 
+ssize_t
+xfs_splice_read(
+        bhv_desc_t              *bdp,
+        struct file             *infilp,
+        struct inode            *pipe,
+        size_t                  count,
+        int                     flags,
+        int                     ioflags,
+        cred_t                  *credp)
+{
+        xfs_inode_t             *ip = XFS_BHVTOI(bdp);
+        xfs_mount_t             *mp = ip->i_mount;
+        ssize_t                 ret;
+
+        XFS_STATS_INC(xs_read_calls);
+        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+                return -EIO;
+
+        xfs_ilock(ip, XFS_IOLOCK_SHARED);
+
+        if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
+            (!(ioflags & IO_INVIS))) {
+                vrwlock_t locktype = VRWLOCK_READ;
+                int error;
+
+                error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
+                                        infilp->f_pos, count,
+                                        FILP_DELAY_FLAG(infilp), &locktype);
+                if (error) {
+                        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+                        return -error;
+                }
+        }
+        xfs_rw_enter_trace(XFS_SPLICE_READ_ENTER, &ip->i_iocore,
+                           pipe, count, infilp->f_pos, ioflags);
+        ret = generic_file_splice_read(infilp, pipe, count, flags);
         if (ret > 0)
                 XFS_STATS_ADD(xs_read_bytes, ret);
 
+        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+        return ret;
+}
+
+ssize_t
+xfs_splice_write(
+        bhv_desc_t              *bdp,
+        struct inode            *pipe,
+        struct file             *outfilp,
+        size_t                  count,
+        int                     flags,
+        int                     ioflags,
+        cred_t                  *credp)
+{
+        xfs_inode_t             *ip = XFS_BHVTOI(bdp);
+        xfs_mount_t             *mp = ip->i_mount;
+        ssize_t                 ret;
+
+        XFS_STATS_INC(xs_write_calls);
+        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+                return -EIO;
+
+        xfs_ilock(ip, XFS_IOLOCK_EXCL);
+
+        if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_WRITE) &&
+            (!(ioflags & IO_INVIS))) {
+                vrwlock_t locktype = VRWLOCK_WRITE;
+                int error;
+
+                error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, BHV_TO_VNODE(bdp),
+                                        outfilp->f_pos, count,
+                                        FILP_DELAY_FLAG(outfilp), &locktype);
+                if (error) {
+                        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+                        return -error;
+                }
+        }
+        xfs_rw_enter_trace(XFS_SPLICE_WRITE_ENTER, &ip->i_iocore,
+                           pipe, count, outfilp->f_pos, ioflags);
+        ret = generic_file_splice_write(pipe, outfilp, count, flags);
+        if (ret > 0)
+                XFS_STATS_ADD(xs_write_bytes, ret);
+
+        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
         return ret;
 }
 
@@ -363,7 +434,7 @@ xfs_zero_last_block(
         xfs_fsize_t     end_size)
 {
         xfs_fileoff_t   last_fsb;
-        xfs_mount_t     *mp;
+        xfs_mount_t     *mp = io->io_mount;
         int             nimaps;
         int             zero_offset;
         int             zero_len;
@@ -373,8 +444,6 @@ xfs_zero_last_block(
 
         ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
 
-        mp = io->io_mount;
-
         zero_offset = XFS_B_FSB_OFFSET(mp, isize);
         if (zero_offset == 0) {
                 /*
@@ -405,10 +474,9 @@ xfs_zero_last_block(
          * don't deadlock when the buffer cache calls back to us.
          */
         XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
-        loff = XFS_FSB_TO_B(mp, last_fsb);
 
+        loff = XFS_FSB_TO_B(mp, last_fsb);
         zero_len = mp->m_sb.sb_blocksize - zero_offset;
-
         error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size);
 
         XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
@@ -441,7 +509,7 @@ xfs_zero_eof(
         xfs_fileoff_t   zero_count_fsb;
         xfs_fileoff_t   last_fsb;
         xfs_extlen_t    buf_len_fsb;
-        xfs_mount_t     *mp;
+        xfs_mount_t     *mp = io->io_mount;
         int             nimaps;
         int             error = 0;
         xfs_bmbt_irec_t imap;
@@ -450,8 +518,6 @@ xfs_zero_eof(
         ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
         ASSERT(offset > isize);
 
-        mp = io->io_mount;
-
         /*
          * First handle zeroing the block on which isize resides.
          * We only zero a part of that block so it is handled specially.
diff --git a/fs/xfs/linux-2.6/xfs_lrw.h b/fs/xfs/linux-2.6/xfs_lrw.h
index 38864a88d42d..eaa5659713fb 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.h
+++ b/fs/xfs/linux-2.6/xfs_lrw.h
@@ -60,6 +60,8 @@ struct xfs_iomap;
 #define XFS_IOMAP_ALLOC_ENTER   25
 #define XFS_IOMAP_ALLOC_MAP     26
 #define XFS_IOMAP_UNWRITTEN     27
+#define XFS_SPLICE_READ_ENTER   28
+#define XFS_SPLICE_WRITE_ENTER  29
 extern void xfs_rw_enter_trace(int, struct xfs_iocore *,
                                 void *, size_t, loff_t, int);
 extern void xfs_inval_cached_trace(struct xfs_iocore *,
@@ -78,6 +80,7 @@ extern int xfs_bmap(struct bhv_desc *, xfs_off_t, ssize_t, int,
                         struct xfs_iomap *, int *);
 extern int xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
 extern int xfs_bdstrat_cb(struct xfs_buf *);
+extern int xfs_dev_is_read_only(struct xfs_mount *, char *);
 
 extern int xfs_zero_eof(struct vnode *, struct xfs_iocore *, xfs_off_t,
                                 xfs_fsize_t, xfs_fsize_t);
@@ -90,7 +93,11 @@ extern ssize_t xfs_write(struct bhv_desc *, struct kiocb *,
 extern ssize_t xfs_sendfile(struct bhv_desc *, struct file *,
                                 loff_t *, int, size_t, read_actor_t,
                                 void *, struct cred *);
-
-extern int xfs_dev_is_read_only(struct xfs_mount *, char *);
+extern ssize_t xfs_splice_read(struct bhv_desc *, struct file *,
+                                struct inode *, size_t, int, int,
+                                struct cred *);
+extern ssize_t xfs_splice_write(struct bhv_desc *, struct inode *,
+                                struct file *, size_t, int, int,
+                                struct cred *);
 
 #endif  /* __XFS_LRW_H__ */
diff --git a/fs/xfs/linux-2.6/xfs_vnode.h b/fs/xfs/linux-2.6/xfs_vnode.h
index 06f5845e9568..6f1c79a28f8b 100644
--- a/fs/xfs/linux-2.6/xfs_vnode.h
+++ b/fs/xfs/linux-2.6/xfs_vnode.h
@@ -173,6 +173,12 @@ typedef ssize_t (*vop_write_t)(bhv_desc_t *, struct kiocb *,
 typedef ssize_t (*vop_sendfile_t)(bhv_desc_t *, struct file *,
                                 loff_t *, int, size_t, read_actor_t,
                                 void *, struct cred *);
+typedef ssize_t (*vop_splice_read_t)(bhv_desc_t *, struct file *,
+                                struct inode *, size_t, int, int,
+                                struct cred *);
+typedef ssize_t (*vop_splice_write_t)(bhv_desc_t *, struct inode *,
+                                struct file *, size_t, int, int,
+                                struct cred *);
 typedef int     (*vop_ioctl_t)(bhv_desc_t *, struct inode *, struct file *,
                                 int, unsigned int, void __user *);
 typedef int     (*vop_getattr_t)(bhv_desc_t *, struct vattr *, int,
@@ -231,6 +237,8 @@ typedef struct vnodeops {
         vop_read_t              vop_read;
         vop_write_t             vop_write;
         vop_sendfile_t          vop_sendfile;
+        vop_splice_read_t       vop_splice_read;
+        vop_splice_write_t      vop_splice_write;
         vop_ioctl_t             vop_ioctl;
         vop_getattr_t           vop_getattr;
         vop_setattr_t           vop_setattr;
@@ -276,6 +284,10 @@ typedef struct vnodeops {
         rv = _VOP_(vop_write, vp)((vp)->v_fbhv,file,iov,segs,offset,ioflags,cr)
 #define VOP_SENDFILE(vp,f,off,ioflags,cnt,act,targ,cr,rv)               \
         rv = _VOP_(vop_sendfile, vp)((vp)->v_fbhv,f,off,ioflags,cnt,act,targ,cr)
+#define VOP_SPLICE_READ(vp,f,pipe,cnt,fl,iofl,cr,rv)                    \
+        rv = _VOP_(vop_splice_read, vp)((vp)->v_fbhv,f,pipe,cnt,fl,iofl,cr)
+#define VOP_SPLICE_WRITE(vp,f,pipe,cnt,fl,iofl,cr,rv)                   \
+        rv = _VOP_(vop_splice_write, vp)((vp)->v_fbhv,f,pipe,cnt,fl,iofl,cr)
 #define VOP_BMAP(vp,of,sz,rw,b,n,rv)                                    \
         rv = _VOP_(vop_bmap, vp)((vp)->v_fbhv,of,sz,rw,b,n)
 #define VOP_OPEN(vp, cr, rv)                                            \