LU-8964 clio: Parallelize generic I/O

[fs/lustre-release.git] / lustre / include / lustre_compat.h

diff --git a/lustre/include/lustre_compat.h b/lustre/include/lustre_compat.h
index 8eff04d..498d27b 100644 (file)
--- a/lustre/include/lustre_compat.h
+++ b/lustre/include/lustre_compat.h
@@ -41,6 +41,7 @@
 
 #include <libcfs/libcfs.h>
 #include <lustre_patchless_compat.h>
+#include <obd_support.h>
 
 #ifdef HAVE_FS_STRUCT_RWLOCK
 # define LOCK_FS_STRUCT(fs)    write_lock(&(fs)->lock)
@@ -442,4 +443,122 @@ static inline void truncate_inode_pages_final(struct address_space *map)
 # define GET_POSIX_ACL_XATTR_ENTRY(head) ((head)->a_entries)
 #endif
 
+#ifndef HAVE_IOV_ITER_TRUNCATE
+static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
+{
+       if (i->count > count)
+               i->count = count;
+}
+#endif
+
+#ifndef HAVE_IS_SXID
+static inline bool is_sxid(umode_t mode)
+{
+       return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
+}
+#endif
+
+#ifndef IS_NOSEC
+#define IS_NOSEC(inode)        (!is_sxid(inode->i_mode))
+#endif
+
+#ifndef HAVE_FILE_OPERATIONS_READ_WRITE_ITER
+static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
+{
+       i->count = count;
+}
+
+static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
+{
+       return (struct iovec) {
+               .iov_base = iter->iov->iov_base + iter->iov_offset,
+               .iov_len = min(iter->count,
+                              iter->iov->iov_len - iter->iov_offset),
+       };
+}
+
+#define iov_for_each(iov, iter, start)                                 \
+       for (iter = (start);                                            \
+            (iter).count && ((iov = iov_iter_iovec(&(iter))), 1);      \
+            iov_iter_advance(&(iter), (iov).iov_len))
+
+static inline ssize_t
+generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+       struct iovec iov;
+       struct iov_iter i;
+       ssize_t bytes = 0;
+
+       iov_for_each(iov, i, *iter) {
+               ssize_t res;
+
+               res = generic_file_aio_read(iocb, &iov, 1, iocb->ki_pos);
+               if (res <= 0) {
+                       if (bytes == 0)
+                               bytes = res;
+                       break;
+               }
+
+               bytes += res;
+               if (res < iov.iov_len)
+                       break;
+       }
+
+       if (bytes > 0)
+               iov_iter_advance(iter, bytes);
+       return bytes;
+}
+
+static inline ssize_t
+__generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+       struct iovec iov;
+       struct iov_iter i;
+       ssize_t bytes = 0;
+
+       /* Since LLITE updates file size at the end of I/O in
+        * vvp_io_commit_write(), append write has to be done in atomic when
+        * there are multiple segments because otherwise each iteration to
+        * __generic_file_aio_write() will see original file size */
+       if (unlikely(iocb->ki_filp->f_flags & O_APPEND && iter->nr_segs > 1)) {
+               struct iovec *iov_copy;
+               int count = 0;
+
+               OBD_ALLOC(iov_copy, sizeof(*iov_copy) * iter->nr_segs);
+               if (!iov_copy)
+                       return -ENOMEM;
+
+               iov_for_each(iov, i, *iter)
+                       iov_copy[count++] = iov;
+
+               bytes = __generic_file_aio_write(iocb, iov_copy, count,
+                                                &iocb->ki_pos);
+               OBD_FREE(iov_copy, sizeof(*iov_copy) * iter->nr_segs);
+
+               if (bytes > 0)
+                       iov_iter_advance(iter, bytes);
+               return bytes;
+       }
+
+       iov_for_each(iov, i, *iter) {
+               ssize_t res;
+
+               res = __generic_file_aio_write(iocb, &iov, 1, &iocb->ki_pos);
+               if (res <= 0) {
+                       if (bytes == 0)
+                               bytes = res;
+                       break;
+               }
+
+               bytes += res;
+               if (res < iov.iov_len)
+                       break;
+       }
+
+       if (bytes > 0)
+               iov_iter_advance(iter, bytes);
+       return bytes;
+}
+#endif /* HAVE_FILE_OPERATIONS_READ_WRITE_ITER */
+
 #endif /* _LUSTRE_COMPAT_H */