include/wrapper/fs.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * wrapper/fs.h
   4  *
   5  * Copyright (C) 2020 Michael Jeanson <mjeanson@efficios.com>
   6  */
   7
   8 #ifndef _LTTNG_WRAPPER_FS_H
   9 #define _LTTNG_WRAPPER_FS_H
  10
  11 #include <linux/fs.h>
  12 #include <lttng/kernel-version.h>
  13
  14 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,14,0))
  15
  16 static inline
  17 ssize_t lttng_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
  18 {
  19         return kernel_read(file, buf, count, pos);
  20 }
  21
  22 #else /* LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,14,0) */
  23
  24 static inline
  25 ssize_t lttng_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
  26 {
  27         ssize_t len;
  28
  29         len = kernel_read(file, *pos, buf, count);
  30
  31         /*
  32          * Move 'pos' forward since it's passed by value in this
  33          * implementation of 'kernel_read'.
  34          */
  35         if (len > 0)
  36                 (*pos) += len;
  37
  38         return len;
  39 }
  40
  41 #endif /* LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,14,0) */
  42
  43 #endif /* _LTTNG_WRAPPER_FS_H */