fs/ext2/file.c

   1 /*
   2  *  linux/fs/ext2/file.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/file.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  ext2 fs regular file handling primitives
  16  *
  17  *  64-bit file support on 64-bit platforms by Jakub Jelinek
  18  *      (jj@sunsite.ms.mff.cuni.cz)
  19  */
  20
  21 #include <linux/time.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/quotaops.h>
  24 #include "ext2.h"
  25 #include "xattr.h"
  26 #include "acl.h"
  27
  28 #ifdef CONFIG_FS_DAX
  29 static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  30 {
  31         return dax_fault(vma, vmf, ext2_get_block, NULL);
  32 }
  33
  34 static int ext2_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
  35 {
  36         return dax_mkwrite(vma, vmf, ext2_get_block, NULL);
  37 }
  38
  39 static const struct vm_operations_struct ext2_dax_vm_ops = {
  40         .fault          = ext2_dax_fault,
  41         .page_mkwrite   = ext2_dax_mkwrite,
  42         .pfn_mkwrite    = dax_pfn_mkwrite,
  43 };
  44
  45 static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
  46 {
  47         if (!IS_DAX(file_inode(file)))
  48                 return generic_file_mmap(file, vma);
  49
  50         file_accessed(file);
  51         vma->vm_ops = &ext2_dax_vm_ops;
  52         vma->vm_flags |= VM_MIXEDMAP;
  53         return 0;
  54 }
  55 #else
  56 #define ext2_file_mmap  generic_file_mmap
  57 #endif
  58
  59 /*
  60  * Called when filp is released. This happens when all file descriptors
  61  * for a single struct file are closed. Note that different open() calls
  62  * for the same file yield different struct file structures.
  63  */
  64 static int ext2_release_file (struct inode * inode, struct file * filp)
  65 {
  66         if (filp->f_mode & FMODE_WRITE) {
  67                 mutex_lock(&EXT2_I(inode)->truncate_mutex);
  68                 ext2_discard_reservation(inode);
  69                 mutex_unlock(&EXT2_I(inode)->truncate_mutex);
  70         }
  71         return 0;
  72 }
  73
  74 int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  75 {
  76         int ret;
  77         struct super_block *sb = file->f_mapping->host->i_sb;
  78         struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
  79
  80         ret = generic_file_fsync(file, start, end, datasync);
  81         if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) {
  82                 /* We don't really know where the IO error happened... */
  83                 ext2_error(sb, __func__,
  84                            "detected IO error when writing metadata buffers");
  85                 ret = -EIO;
  86         }
  87         return ret;
  88 }
  89
  90 /*
  91  * We have mostly NULL's here: the current defaults are ok for
  92  * the ext2 filesystem.
  93  */
  94 const struct file_operations ext2_file_operations = {
  95         .llseek         = generic_file_llseek,
  96         .read_iter      = generic_file_read_iter,
  97         .write_iter     = generic_file_write_iter,
  98         .unlocked_ioctl = ext2_ioctl,
  99 #ifdef CONFIG_COMPAT
 100         .compat_ioctl   = ext2_compat_ioctl,
 101 #endif
 102         .mmap           = ext2_file_mmap,
 103         .open           = dquot_file_open,
 104         .release        = ext2_release_file,
 105         .fsync          = ext2_fsync,
 106         .splice_read    = generic_file_splice_read,
 107         .splice_write   = iter_file_splice_write,
 108 };
 109
 110 const struct inode_operations ext2_file_inode_operations = {
 111 #ifdef CONFIG_EXT2_FS_XATTR
 112         .setxattr       = generic_setxattr,
 113         .getxattr       = generic_getxattr,
 114         .listxattr      = ext2_listxattr,
 115         .removexattr    = generic_removexattr,
 116 #endif
 117         .setattr        = ext2_setattr,
 118         .get_acl        = ext2_get_acl,
 119         .set_acl        = ext2_set_acl,
 120         .fiemap         = ext2_fiemap,
 121 };