[PATCH] splice: pass offset around for ->splice_read() and ->splice_write()
Jens Axboe [Tue, 11 Apr 2006 12:57:50 +0000 (14:57 +0200)]
We need not use ->f_pos as the offset for the file input/output. If the
user passed an offset pointer in through sys_splice(), just use that and
leave ->f_pos alone.

Signed-off-by: Jens Axboe <axboe@suse.de>

fs/splice.c
fs/xfs/linux-2.6/xfs_file.c
fs/xfs/linux-2.6/xfs_lrw.c
fs/xfs/linux-2.6/xfs_lrw.h
fs/xfs/linux-2.6/xfs_vnode.h
include/linux/fs.h

index e50a460..5d3eda6 100644 (file)
@@ -231,8 +231,9 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages,
 }
 
 static int
-__generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe,
-                          size_t len, unsigned int flags)
+__generic_file_splice_read(struct file *in, loff_t *ppos,
+                          struct pipe_inode_info *pipe, size_t len,
+                          unsigned int flags)
 {
        struct address_space *mapping = in->f_mapping;
        unsigned int offset, nr_pages;
@@ -241,8 +242,8 @@ __generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe,
        pgoff_t index;
        int i, error;
 
-       index = in->f_pos >> PAGE_CACHE_SHIFT;
-       offset = in->f_pos & ~PAGE_CACHE_MASK;
+       index = *ppos >> PAGE_CACHE_SHIFT;
+       offset = *ppos & ~PAGE_CACHE_MASK;
        nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
        if (nr_pages > PIPE_BUFFERS)
@@ -348,8 +349,9 @@ fill_it:
  *
  * Will read pages from given file and fill them into a pipe.
  */
-ssize_t generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe,
-                                size_t len, unsigned int flags)
+ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
+                                struct pipe_inode_info *pipe, size_t len,
+                                unsigned int flags)
 {
        ssize_t spliced;
        int ret;
@@ -358,12 +360,12 @@ ssize_t generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe,
        spliced = 0;
 
        while (len) {
-               ret = __generic_file_splice_read(in, pipe, len, flags);
+               ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
 
                if (ret <= 0)
                        break;
 
-               in->f_pos += ret;
+               *ppos += ret;
                len -= ret;
                spliced += ret;
 
@@ -561,7 +563,7 @@ typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
  * to the wanted destination. See pipe_to_file/pipe_to_sendpage above.
  */
 static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out,
-                             size_t len, unsigned int flags,
+                             loff_t *ppos, size_t len, unsigned int flags,
                              splice_actor *actor)
 {
        int ret, do_wakeup, err;
@@ -573,7 +575,7 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out,
        sd.total_len = len;
        sd.flags = flags;
        sd.file = out;
-       sd.pos = out->f_pos;
+       sd.pos = *ppos;
 
        if (pipe->inode)
                mutex_lock(&pipe->inode->i_mutex);
@@ -656,9 +658,7 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out,
                kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
        }
 
-       out->f_pos = sd.pos;
        return ret;
-
 }
 
 /**
@@ -674,12 +674,12 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out,
  */
 ssize_t
 generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
-                         size_t len, unsigned int flags)
+                         loff_t *ppos, size_t len, unsigned int flags)
 {
        struct address_space *mapping = out->f_mapping;
        ssize_t ret;
 
-       ret = move_from_pipe(pipe, out, len, flags, pipe_to_file);
+       ret = move_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
 
        /*
         * If file or inode is SYNC and we actually wrote some data, sync it.
@@ -715,9 +715,9 @@ EXPORT_SYMBOL(generic_file_splice_write);
  *
  */
 ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
-                               size_t len, unsigned int flags)
+                               loff_t *ppos, size_t len, unsigned int flags)
 {
-       return move_from_pipe(pipe, out, len, flags, pipe_to_sendpage);
+       return move_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
 }
 
 EXPORT_SYMBOL(generic_splice_sendpage);
@@ -726,9 +726,8 @@ EXPORT_SYMBOL(generic_splice_sendpage);
  * Attempt to initiate a splice from pipe to file.
  */
 static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
-                          size_t len, unsigned int flags)
+                          loff_t *ppos, size_t len, unsigned int flags)
 {
-       loff_t pos;
        int ret;
 
        if (unlikely(!out->f_op || !out->f_op->splice_write))
@@ -737,22 +736,21 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
        if (unlikely(!(out->f_mode & FMODE_WRITE)))
                return -EBADF;
 
-       pos = out->f_pos;
-
-       ret = rw_verify_area(WRITE, out, &pos, len);
+       ret = rw_verify_area(WRITE, out, ppos, len);
        if (unlikely(ret < 0))
                return ret;
 
-       return out->f_op->splice_write(pipe, out, len, flags);
+       return out->f_op->splice_write(pipe, out, ppos, len, flags);
 }
 
 /*
  * Attempt to initiate a splice from a file to a pipe.
  */
-static long do_splice_to(struct file *in, struct pipe_inode_info *pipe,
-                        size_t len, unsigned int flags)
+static long do_splice_to(struct file *in, loff_t *ppos,
+                        struct pipe_inode_info *pipe, size_t len,
+                        unsigned int flags)
 {
-       loff_t pos, isize, left;
+       loff_t isize, left;
        int ret;
 
        if (unlikely(!in->f_op || !in->f_op->splice_read))
@@ -761,28 +759,27 @@ static long do_splice_to(struct file *in, struct pipe_inode_info *pipe,
        if (unlikely(!(in->f_mode & FMODE_READ)))
                return -EBADF;
 
-       pos = in->f_pos;
-
-       ret = rw_verify_area(READ, in, &pos, len);
+       ret = rw_verify_area(READ, in, ppos, len);
        if (unlikely(ret < 0))
                return ret;
 
        isize = i_size_read(in->f_mapping->host);
-       if (unlikely(in->f_pos >= isize))
+       if (unlikely(*ppos >= isize))
                return 0;
        
-       left = isize - in->f_pos;
+       left = isize - *ppos;
        if (unlikely(left < len))
                len = left;
 
-       return in->f_op->splice_read(in, pipe, len, flags);
+       return in->f_op->splice_read(in, ppos, pipe, len, flags);
 }
 
-long do_splice_direct(struct file *in, struct file *out, size_t len,
-                     unsigned int flags)
+long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
+                     size_t len, unsigned int flags)
 {
        struct pipe_inode_info *pipe;
        long ret, bytes;
+       loff_t out_off;
        umode_t i_mode;
        int i;
 
@@ -820,6 +817,7 @@ long do_splice_direct(struct file *in, struct file *out, size_t len,
         */
        ret = 0;
        bytes = 0;
+       out_off = 0;
 
        while (len) {
                size_t read_len, max_read_len;
@@ -829,7 +827,7 @@ long do_splice_direct(struct file *in, struct file *out, size_t len,
                 */
                max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE));
 
-               ret = do_splice_to(in, pipe, max_read_len, flags);
+               ret = do_splice_to(in, ppos, pipe, max_read_len, flags);
                if (unlikely(ret < 0))
                        goto out_release;
 
@@ -840,7 +838,7 @@ long do_splice_direct(struct file *in, struct file *out, size_t len,
                 * must not do the output in nonblocking mode as then we
                 * could get stuck data in the internal pipe:
                 */
-               ret = do_splice_from(pipe, out, read_len,
+               ret = do_splice_from(pipe, out, &out_off, read_len,
                                     flags & ~SPLICE_F_NONBLOCK);
                if (unlikely(ret < 0))
                        goto out_release;
@@ -898,6 +896,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                      size_t len, unsigned int flags)
 {
        struct pipe_inode_info *pipe;
+       loff_t offset, *off;
 
        pipe = in->f_dentry->d_inode->i_pipe;
        if (pipe) {
@@ -906,12 +905,13 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                if (off_out) {
                        if (out->f_op->llseek == no_llseek)
                                return -EINVAL;
-                       if (copy_from_user(&out->f_pos, off_out,
-                                          sizeof(loff_t)))
+                       if (copy_from_user(&offset, off_out, sizeof(loff_t)))
                                return -EFAULT;
-               }
+                       off = &offset;
+               } else
+                       off = &out->f_pos;
 
-               return do_splice_from(pipe, out, len, flags);
+               return do_splice_from(pipe, out, off, len, flags);
        }
 
        pipe = out->f_dentry->d_inode->i_pipe;
@@ -921,11 +921,13 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                if (off_in) {
                        if (in->f_op->llseek == no_llseek)
                                return -EINVAL;
-                       if (copy_from_user(&in->f_pos, off_in, sizeof(loff_t)))
+                       if (copy_from_user(&offset, off_in, sizeof(loff_t)))
                                return -EFAULT;
-               }
+                       off = &offset;
+               } else
+                       off = &in->f_pos;
 
-               return do_splice_to(in, pipe, len, flags);
+               return do_splice_to(in, off, pipe, len, flags);
        }
 
        return -EINVAL;
index 269721a..c847416 100644 (file)
@@ -252,6 +252,7 @@ xfs_file_sendfile_invis(
 STATIC ssize_t
 xfs_file_splice_read(
        struct file             *infilp,
+       loff_t                  *ppos,
        struct pipe_inode_info  *pipe,
        size_t                  len,
        unsigned int            flags)
@@ -259,13 +260,14 @@ xfs_file_splice_read(
        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);
+       VOP_SPLICE_READ(vp, infilp, ppos, pipe, len, flags, 0, NULL, rval);
        return rval;
 }
 
 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)
@@ -273,7 +275,7 @@ xfs_file_splice_read_invis(
        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);
+       VOP_SPLICE_READ(vp, infilp, ppos, pipe, len, flags, IO_INVIS, NULL, rval);
        return rval;
 }
 
@@ -281,13 +283,14 @@ STATIC ssize_t
 xfs_file_splice_write(
        struct pipe_inode_info  *pipe,
        struct file             *outfilp,
+       loff_t                  *ppos,
        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);
+       VOP_SPLICE_WRITE(vp, pipe, outfilp, ppos, len, flags, 0, NULL, rval);
        return rval;
 }
 
@@ -295,13 +298,14 @@ 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)
 {
        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);
+       VOP_SPLICE_WRITE(vp, pipe, outfilp, ppos, len, flags, IO_INVIS, NULL, rval);
        return rval;
 }
 
index 74a5293..67efe33 100644 (file)
@@ -338,6 +338,7 @@ ssize_t
 xfs_splice_read(
        bhv_desc_t              *bdp,
        struct file             *infilp,
+       loff_t                  *ppos,
        struct pipe_inode_info  *pipe,
        size_t                  count,
        int                     flags,
@@ -360,7 +361,7 @@ xfs_splice_read(
                int error;
 
                error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
-                                       infilp->f_pos, count,
+                                       *ppos, count,
                                        FILP_DELAY_FLAG(infilp), &locktype);
                if (error) {
                        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@@ -368,8 +369,8 @@ xfs_splice_read(
                }
        }
        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);
+                          pipe, count, *ppos, ioflags);
+       ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
        if (ret > 0)
                XFS_STATS_ADD(xs_read_bytes, ret);
 
@@ -382,6 +383,7 @@ xfs_splice_write(
        bhv_desc_t              *bdp,
        struct pipe_inode_info  *pipe,
        struct file             *outfilp,
+       loff_t                  *ppos,
        size_t                  count,
        int                     flags,
        int                     ioflags,
@@ -403,7 +405,7 @@ xfs_splice_write(
                int error;
 
                error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, BHV_TO_VNODE(bdp),
-                                       outfilp->f_pos, count,
+                                       *ppos, count,
                                        FILP_DELAY_FLAG(outfilp), &locktype);
                if (error) {
                        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
@@ -411,8 +413,8 @@ xfs_splice_write(
                }
        }
        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);
+                          pipe, count, *ppos, ioflags);
+       ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
        if (ret > 0)
                XFS_STATS_ADD(xs_write_bytes, ret);
 
index 55c689a..8f45399 100644 (file)
@@ -93,11 +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 ssize_t xfs_splice_read(struct bhv_desc *, struct file *,
+extern ssize_t xfs_splice_read(struct bhv_desc *, struct file *, loff_t *,
                                struct pipe_inode_info *, size_t, int, int,
                                struct cred *);
 extern ssize_t xfs_splice_write(struct bhv_desc *, struct pipe_inode_info *,
-                               struct file *, size_t, int, int,
+                               struct file *, loff_t *, size_t, int, int,
                                struct cred *);
 
 #endif /* __XFS_LRW_H__ */
index 88b09f1..2a8e16c 100644 (file)
@@ -173,11 +173,11 @@ 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 *,
+typedef ssize_t (*vop_splice_read_t)(bhv_desc_t *, struct file *, loff_t *,
                                struct pipe_inode_info *, size_t, int, int,
                                struct cred *);
 typedef ssize_t (*vop_splice_write_t)(bhv_desc_t *, struct pipe_inode_info *,
-                               struct file *, size_t, int, int,
+                               struct file *, loff_t *, size_t, int, int,
                                struct cred *);
 typedef int    (*vop_ioctl_t)(bhv_desc_t *, struct inode *, struct file *,
                                int, unsigned int, void __user *);
@@ -284,10 +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_SPLICE_READ(vp,f,o,pipe,cnt,fl,iofl,cr,rv)                 \
+       rv = _VOP_(vop_splice_read, vp)((vp)->v_fbhv,f,o,pipe,cnt,fl,iofl,cr)
+#define VOP_SPLICE_WRITE(vp,f,o,pipe,cnt,fl,iofl,cr,rv)                        \
+       rv = _VOP_(vop_splice_write, vp)((vp)->v_fbhv,f,o,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)                                           \
index 162c6e5..3de2bfb 100644 (file)
@@ -1039,8 +1039,8 @@ struct file_operations {
        int (*check_flags)(int);
        int (*dir_notify)(struct file *filp, unsigned long arg);
        int (*flock) (struct file *, int, struct file_lock *);
-       ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, size_t, unsigned int);
-       ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned int);
+       ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
+       ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
 };
 
 struct inode_operations {
@@ -1613,13 +1613,13 @@ extern void do_generic_mapping_read(struct address_space *mapping,
                                    loff_t *, read_descriptor_t *, read_actor_t);
 
 /* fs/splice.c */
-extern ssize_t generic_file_splice_read(struct file *,
+extern ssize_t generic_file_splice_read(struct file *, loff_t *,
                struct pipe_inode_info *, size_t, unsigned int);
 extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
-               struct file *, size_t, unsigned int);
+               struct file *, loff_t *, size_t, unsigned int);
 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
-               struct file *out, size_t len, unsigned int flags);
-extern long do_splice_direct(struct file *in, struct file *out,
+               struct file *out, loff_t *, size_t len, unsigned int flags);
+extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                size_t len, unsigned int flags);
 
 extern void