splice: don't pass the address of ->f_pos to methods

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/internal.h b/fs/internal.h
index eaa75f75b625c572ec6e75650b3e6fb89d715a4a..68121584ae37d40a074bf81e55184ecb1674d882 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -131,6 +131,12 @@ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
  */
 extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
 
+/*
+ * splice.c
+ */
+extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
+               loff_t *opos, size_t len, unsigned int flags);
+
 /*
  * pipe.c
  */

diff --git a/fs/read_write.c b/fs/read_write.c
index 03430008704e68fd74470e8dbb9fcb637dce3f97..2cefa417be349b0016ffa8606635db9e85751015 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1064,6 +1064,7 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
        struct fd in, out;
        struct inode *in_inode, *out_inode;
        loff_t pos;
+       loff_t out_pos;
        ssize_t retval;
        int fl;
 
@@ -1077,12 +1078,14 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
        if (!(in.file->f_mode & FMODE_READ))
                goto fput_in;
        retval = -ESPIPE;
-       if (!ppos)
-               ppos = &in.file->f_pos;
-       else
+       if (!ppos) {
+               pos = in.file->f_pos;
+       } else {
+               pos = *ppos;
                if (!(in.file->f_mode & FMODE_PREAD))
                        goto fput_in;
-       retval = rw_verify_area(READ, in.file, ppos, count);
+       }
+       retval = rw_verify_area(READ, in.file, &pos, count);
        if (retval < 0)
                goto fput_in;
        count = retval;
@@ -1099,7 +1102,8 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
        retval = -EINVAL;
        in_inode = file_inode(in.file);
        out_inode = file_inode(out.file);
-       retval = rw_verify_area(WRITE, out.file, &out.file->f_pos, count);
+       out_pos = out.file->f_pos;
+       retval = rw_verify_area(WRITE, out.file, &out_pos, count);
        if (retval < 0)
                goto fput_out;
        count = retval;
@@ -1107,7 +1111,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
        if (!max)
                max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
 
-       pos = *ppos;
        if (unlikely(pos + count > max)) {
                retval = -EOVERFLOW;
                if (pos >= max)
@@ -1126,18 +1129,23 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
        if (in.file->f_flags & O_NONBLOCK)
                fl = SPLICE_F_NONBLOCK;
 #endif
-       retval = do_splice_direct(in.file, ppos, out.file, count, fl);
+       retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
 
        if (retval > 0) {
                add_rchar(current, retval);
                add_wchar(current, retval);
                fsnotify_access(in.file);
                fsnotify_modify(out.file);
+               out.file->f_pos = out_pos;
+               if (ppos)
+                       *ppos = pos;
+               else
+                       in.file->f_pos = pos;
        }
 
        inc_syscr(current);
        inc_syscw(current);
-       if (*ppos > max)
+       if (pos > max)
                retval = -EOVERFLOW;
 
 fput_out:

diff --git a/fs/splice.c b/fs/splice.c
index e6b25598c8c413d66026f96e6d6d1b351e28b62c..9eca476227d535eb29c74dfa7aaf324167f7e93f 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1274,7 +1274,7 @@ static int direct_splice_actor(struct pipe_inode_info *pipe,
 {
        struct file *file = sd->u.file;
 
-       return do_splice_from(pipe, file, &file->f_pos, sd->total_len,
+       return do_splice_from(pipe, file, sd->opos, sd->total_len,
                              sd->flags);
 }
 
@@ -1294,7 +1294,7 @@ static int direct_splice_actor(struct pipe_inode_info *pipe,
  *
  */
 long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
-                     size_t len, unsigned int flags)
+                     loff_t *opos, size_t len, unsigned int flags)
 {
        struct splice_desc sd = {
                .len            = len,
@@ -1302,6 +1302,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                .flags          = flags,
                .pos            = *ppos,
                .u.file         = out,
+               .opos           = opos,
        };
        long ret;
 
@@ -1325,7 +1326,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
 {
        struct pipe_inode_info *ipipe;
        struct pipe_inode_info *opipe;
-       loff_t offset, *off;
+       loff_t offset;
        long ret;
 
        ipipe = get_pipe_info(in);
@@ -1356,13 +1357,15 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                                return -EINVAL;
                        if (copy_from_user(&offset, off_out, sizeof(loff_t)))
                                return -EFAULT;
-                       off = &offset;
-               } else
-                       off = &out->f_pos;
+               } else {
+                       offset = out->f_pos;
+               }
 
-               ret = do_splice_from(ipipe, out, off, len, flags);
+               ret = do_splice_from(ipipe, out, &offset, len, flags);
 
-               if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
+               if (!off_out)
+                       out->f_pos = offset;
+               else if (copy_to_user(off_out, &offset, sizeof(loff_t)))
                        ret = -EFAULT;
 
                return ret;
@@ -1376,13 +1379,15 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                                return -EINVAL;
                        if (copy_from_user(&offset, off_in, sizeof(loff_t)))
                                return -EFAULT;
-                       off = &offset;
-               } else
-                       off = &in->f_pos;
+               } else {
+                       offset = in->f_pos;
+               }
 
-               ret = do_splice_to(in, off, opipe, len, flags);
+               ret = do_splice_to(in, &offset, opipe, len, flags);
 
-               if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
+               if (!off_in)
+                       in->f_pos = offset;
+               else if (copy_to_user(off_in, &offset, sizeof(loff_t)))
                        ret = -EFAULT;
 
                return ret;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 43db02e9c9fa11bed1b058fba9dd9039ea9c226d..65c2be22b601cc40c17b175e4a88f8980979cc62 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2414,8 +2414,6 @@ extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
                struct file *, loff_t *, size_t, unsigned int);
 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
                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
 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);

diff --git a/include/linux/splice.h b/include/linux/splice.h
index 09a545a7dfa39bcd7f736f446358d4c3b112aae4..74575cbf2d6f579c317fec5f1f16e9d3793fab03 100644 (file)
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -35,6 +35,7 @@ struct splice_desc {
                void *data;             /* cookie */
        } u;
        loff_t pos;                     /* file position */
+       loff_t *opos;                   /* sendfile: output position */
        size_t num_spliced;             /* number of bytes already spliced */
        bool need_wakeup;               /* need to wake up writer */
 };