kill generic_segment_checks()

all callers of ->aio_read() and ->aio_write() have iov/nr_segs already
checked - generic_segment_checks() done after that is just an odd way
to spell iov_length().

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

10 files changed, 16 insertions, 104 deletions

diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 8e844a6371e0..220bd8390a84 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -1180,9 +1180,7 @@ static ssize_t ll_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
         ssize_t      result;
         int              refcheck;
 
-        result = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
-        if (result)
-                return result;
+        count = iov_length(iov, nr_segs);
 
         env = cl_env_get(&refcheck);
         if (IS_ERR(env))
@@ -1235,14 +1233,10 @@ static ssize_t ll_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 {
         struct lu_env      *env;
         struct vvp_io_args *args;
-        size_t        count = 0;
+        size_t        count = iov_length(iov, nr_segs);
         ssize_t      result;
         int              refcheck;
 
-        result = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
-        if (result)
-                return result;
-
         env = cl_env_get(&refcheck);
         if (IS_ERR(env))
                 return PTR_ERR(env);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 1dafe0701daf..a0a94a30d85a 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1726,12 +1726,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 
         mutex_lock(&inode->i_mutex);
 
-        err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
-        if (err) {
-                mutex_unlock(&inode->i_mutex);
-                goto out;
-        }
-        count = ocount;
+        count = ocount = iov_length(iov, nr_segs);
 
         current->backing_dev_info = inode->i_mapping->backing_dev_info;
         err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ef9115e4a6fa..21a56c27b74c 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -828,12 +828,8 @@ again:
                      inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
                      ceph_cap_string(got));
 
-                if (!read) {
-                        ret = generic_segment_checks(iov, &nr_segs,
-                                                        &len, VERIFY_WRITE);
-                        if (ret)
-                                goto out;
-                }
+                if (!read)
+                        len = iov_length(iov, nr_segs);
 
                 iov_iter_init(&i, iov, nr_segs, len, read);
 
@@ -855,7 +851,6 @@ again:
 
                 ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
         }
-out:
         dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
              inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
         ceph_put_cap_refs(ci, got);
@@ -911,9 +906,7 @@ static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
         mutex_lock(&inode->i_mutex);
 
-        err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
-        if (err)
-                goto out;
+        count = iov_length(iov, nr_segs);
 
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = file->f_mapping->backing_dev_info;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 126deb5d0a9c..9c7f346879e7 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1208,12 +1208,7 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
         WARN_ON(iocb->ki_pos != pos);
 
-        ocount = 0;
-        err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
-        if (err)
-                return err;
-
-        count = ocount;
+        count = ocount = iov_length(iov, nr_segs);
         mutex_lock(&inode->i_mutex);
 
         /* We can write back this queue in page reclaim */
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index db9bd8a31725..b6fa457d8d01 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -2091,10 +2091,7 @@ static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb,
         size_t count;           /* after file limit checks */
         ssize_t written, err;
 
-        count = 0;
-        err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
-        if (err)
-                return err;
+        count = iov_length(iov, nr_segs);
         pos = *ppos;
         /* We can write back this queue in page reclaim. */
         current->backing_dev_info = mapping->backing_dev_info;
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index d6d78c2aa96e..d33c4ced0baf 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2355,12 +2355,7 @@ relock:
         /* communicate with ocfs2_dio_end_io */
         ocfs2_iocb_set_rw_locked(iocb, rw_level);
 
-        ret = generic_segment_checks(iov, &nr_segs, &ocount,
-                                     VERIFY_READ);
-        if (ret)
-                goto out_dio;
-
-        count = ocount;
+        count = ocount = iov_length(iov, nr_segs);
         ret = generic_write_checks(file, ppos, &count,
                                    S_ISBLK(inode->i_mode));
         if (ret)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 8617497867c7..f0f8084a67be 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -253,9 +253,7 @@ xfs_file_aio_read(
         if (file->f_mode & FMODE_NOCMTIME)
                 ioflags |= IO_INVIS;
 
-        ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
-        if (ret < 0)
-                return ret;
+        size = iov_length(iovp, nr_segs);
 
         if (unlikely(ioflags & IO_ISDIRECT)) {
                 xfs_buftarg_t   *target =
@@ -777,10 +775,7 @@ xfs_file_aio_write(
 
         BUG_ON(iocb->ki_pos != pos);
 
-        ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
-        if (ret)
-                return ret;
-
+        ocount = iov_length(iovp, nr_segs);
         if (ocount == 0)
                 return 0;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 262f96e579b8..796de742fe4a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2412,8 +2412,6 @@ extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *,
 extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
-extern int generic_segment_checks(const struct iovec *iov,
-                unsigned long *nr_segs, size_t *count, int access_flags);
 
 /* fs/block_dev.c */
 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
diff --git a/mm/filemap.c b/mm/filemap.c
index a840890ed39f..7c1417b0bd7b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1663,45 +1663,6 @@ out:
         return written ? written : error;
 }
 
-/*
- * Performs necessary checks before doing a write
- * @iov:        io vector request
- * @nr_segs:    number of segments in the iovec
- * @count:      number of bytes to write
- * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE
- *
- * Adjust number of segments and amount of bytes to write (nr_segs should be
- * properly initialized first). Returns appropriate error code that caller
- * should return or zero in case that write should be allowed.
- */
-int generic_segment_checks(const struct iovec *iov,
-                        unsigned long *nr_segs, size_t *count, int access_flags)
-{
-        unsigned long   seg;
-        size_t cnt = 0;
-        for (seg = 0; seg < *nr_segs; seg++) {
-                const struct iovec *iv = &iov[seg];
-
-                /*
-                 * If any segment has a negative length, or the cumulative
-                 * length ever wraps negative then return -EINVAL.
-                 */
-                cnt += iv->iov_len;
-                if (unlikely((ssize_t)(cnt|iv->iov_len) < 0))
-                        return -EINVAL;
-                if (access_ok(access_flags, iv->iov_base, iv->iov_len))
-                        continue;
-                if (seg == 0)
-                        return -EFAULT;
-                *nr_segs = seg;
-                cnt -= iv->iov_len;     /* This segment is no good */
-                break;
-        }
-        *count = cnt;
-        return 0;
-}
-EXPORT_SYMBOL(generic_segment_checks);
-
 /**
  * generic_file_aio_read - generic filesystem read routine
  * @iocb:       kernel I/O control block
@@ -1717,15 +1678,12 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
                 unsigned long nr_segs, loff_t pos)
 {
         struct file *filp = iocb->ki_filp;
-        ssize_t retval;
+        ssize_t retval = 0;
         size_t count;
         loff_t *ppos = &iocb->ki_pos;
         struct iov_iter i;
 
-        count = 0;
-        retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
-        if (retval)
-                return retval;
+        count = iov_length(iov, nr_segs);
         iov_iter_init(&i, iov, nr_segs, count, 0);
 
         /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
@@ -2615,12 +2573,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         ssize_t         status;
         struct iov_iter from;
 
-        ocount = 0;
-        err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
-        if (err)
-                return err;
-
-        count = ocount;
+        count = ocount = iov_length(iov, nr_segs);
 
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = mapping->backing_dev_info;
diff --git a/mm/shmem.c b/mm/shmem.c
index 9f70e02111c6..2a93e625adaf 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1412,14 +1412,11 @@ static ssize_t shmem_file_aio_read(struct kiocb *iocb,
         unsigned long offset;
         enum sgp_type sgp = SGP_READ;
         int error = 0;
-        ssize_t retval;
-        size_t count;
+        ssize_t retval = 0;
+        size_t count = iov_length(iov, nr_segs);
         loff_t *ppos = &iocb->ki_pos;
         struct iov_iter iter;
 
-        retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
-        if (retval)
-                return retval;
         iov_iter_init(&iter, iov, nr_segs, count, 0);
 
         /*