1 /* 2 * linux/fs/ext4/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 * ext4 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/fs.h> 23 #include <linux/jbd2.h> 24 #include <linux/mount.h> 25 #include <linux/path.h> 26 #include "ext4.h" 27 #include "ext4_jbd2.h" 28 #include "xattr.h" 29 #include "acl.h" 30 31 /* 32 * Called when an inode is released. Note that this is different 33 * from ext4_file_open: open gets called at every open, but release 34 * gets called only when /all/ the files are closed. 35 */ 36 static int ext4_release_file(struct inode *inode, struct file *filp) 37 { 38 if (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) { 39 ext4_alloc_da_blocks(inode); 40 EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE; 41 } 42 /* if we are the last writer on the inode, drop the block reservation */ 43 if ((filp->f_mode & FMODE_WRITE) && 44 (atomic_read(&inode->i_writecount) == 1) && 45 !EXT4_I(inode)->i_reserved_data_blocks) 46 { 47 down_write(&EXT4_I(inode)->i_data_sem); 48 ext4_discard_preallocations(inode); 49 up_write(&EXT4_I(inode)->i_data_sem); 50 } 51 if (is_dx(inode) && filp->private_data) 52 ext4_htree_free_dir_info(filp->private_data); 53 54 return 0; 55 } 56 57 static ssize_t 58 ext4_file_write(struct kiocb *iocb, const struct iovec *iov, 59 unsigned long nr_segs, loff_t pos) 60 { 61 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; 62 63 /* 64 * If we have encountered a bitmap-format file, the size limit 65 * is smaller than s_maxbytes, which is for extent-mapped files. 66 */ 67 68 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) { 69 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 70 size_t length = iov_length(iov, nr_segs); 71 72 if (pos > sbi->s_bitmap_maxbytes) 73 return -EFBIG; 74 75 if (pos + length > sbi->s_bitmap_maxbytes) { 76 nr_segs = iov_shorten((struct iovec *)iov, nr_segs, 77 sbi->s_bitmap_maxbytes - pos); 78 } 79 } 80 81 return generic_file_aio_write(iocb, iov, nr_segs, pos); 82 } 83 84 static const struct vm_operations_struct ext4_file_vm_ops = { 85 .fault = filemap_fault, 86 .page_mkwrite = ext4_page_mkwrite, 87 }; 88 89 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) 90 { 91 struct address_space *mapping = file->f_mapping; 92 93 if (!mapping->a_ops->readpage) 94 return -ENOEXEC; 95 file_accessed(file); 96 vma->vm_ops = &ext4_file_vm_ops; 97 vma->vm_flags |= VM_CAN_NONLINEAR; 98 return 0; 99 } 100 101 static int ext4_file_open(struct inode * inode, struct file * filp) 102 { 103 struct super_block *sb = inode->i_sb; 104 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 105 struct vfsmount *mnt = filp->f_path.mnt; 106 struct path path; 107 char buf[64], *cp; 108 109 if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) && 110 !(sb->s_flags & MS_RDONLY))) { 111 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; 112 /* 113 * Sample where the filesystem has been mounted and 114 * store it in the superblock for sysadmin convenience 115 * when trying to sort through large numbers of block 116 * devices or filesystem images. 117 */ 118 memset(buf, 0, sizeof(buf)); 119 path.mnt = mnt->mnt_parent; 120 path.dentry = mnt->mnt_mountpoint; 121 path_get(&path); 122 cp = d_path(&path, buf, sizeof(buf)); 123 path_put(&path); 124 if (!IS_ERR(cp)) { 125 memcpy(sbi->s_es->s_last_mounted, cp, 126 sizeof(sbi->s_es->s_last_mounted)); 127 sb->s_dirt = 1; 128 } 129 } 130 return generic_file_open(inode, filp); 131 } 132 133 const struct file_operations ext4_file_operations = { 134 .llseek = generic_file_llseek, 135 .read = do_sync_read, 136 .write = do_sync_write, 137 .aio_read = generic_file_aio_read, 138 .aio_write = ext4_file_write, 139 .unlocked_ioctl = ext4_ioctl, 140 #ifdef CONFIG_COMPAT 141 .compat_ioctl = ext4_compat_ioctl, 142 #endif 143 .mmap = ext4_file_mmap, 144 .open = ext4_file_open, 145 .release = ext4_release_file, 146 .fsync = ext4_sync_file, 147 .splice_read = generic_file_splice_read, 148 .splice_write = generic_file_splice_write, 149 }; 150 151 const struct inode_operations ext4_file_inode_operations = { 152 .truncate = ext4_truncate, 153 .setattr = ext4_setattr, 154 .getattr = ext4_getattr, 155 #ifdef CONFIG_EXT4_FS_XATTR 156 .setxattr = generic_setxattr, 157 .getxattr = generic_getxattr, 158 .listxattr = ext4_listxattr, 159 .removexattr = generic_removexattr, 160 #endif 161 .check_acl = ext4_check_acl, 162 .fallocate = ext4_fallocate, 163 .fiemap = ext4_fiemap, 164 }; 165 166