[XFS] Provide XFS support for the splice syscall.

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

1 files changed, 93 insertions, 27 deletions

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.