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 <linux/quotaops.h> 27 #include "ext4.h" 28 #include "ext4_jbd2.h" 29 #include "xattr.h" 30 #include "acl.h" 31 32 /* 33 * Called when an inode is released. Note that this is different 34 * from ext4_file_open: open gets called at every open, but release 35 * gets called only when /all/ the files are closed. 36 */ 37 static int ext4_release_file(struct inode *inode, struct file *filp) 38 { 39 if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) { 40 ext4_alloc_da_blocks(inode); 41 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); 42 } 43 /* if we are the last writer on the inode, drop the block reservation */ 44 if ((filp->f_mode & FMODE_WRITE) && 45 (atomic_read(&inode->i_writecount) == 1) && 46 !EXT4_I(inode)->i_reserved_data_blocks) 47 { 48 down_write(&EXT4_I(inode)->i_data_sem); 49 ext4_discard_preallocations(inode); 50 up_write(&EXT4_I(inode)->i_data_sem); 51 } 52 if (is_dx(inode) && filp->private_data) 53 ext4_htree_free_dir_info(filp->private_data); 54 55 return 0; 56 } 57 58 static ssize_t 59 ext4_file_write(struct kiocb *iocb, const struct iovec *iov, 60 unsigned long nr_segs, loff_t pos) 61 { 62 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; 63 64 /* 65 * If we have encountered a bitmap-format file, the size limit 66 * is smaller than s_maxbytes, which is for extent-mapped files. 67 */ 68 69 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { 70 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 71 size_t length = iov_length(iov, nr_segs); 72 73 if ((pos > sbi->s_bitmap_maxbytes || 74 (pos == sbi->s_bitmap_maxbytes && length > 0))) 75 return -EFBIG; 76 77 if (pos + length > sbi->s_bitmap_maxbytes) { 78 nr_segs = iov_shorten((struct iovec *)iov, nr_segs, 79 sbi->s_bitmap_maxbytes - pos); 80 } 81 } 82 83 return generic_file_aio_write(iocb, iov, nr_segs, pos); 84 } 85 86 static const struct vm_operations_struct ext4_file_vm_ops = { 87 .fault = filemap_fault, 88 .page_mkwrite = ext4_page_mkwrite, 89 }; 90 91 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) 92 { 93 struct address_space *mapping = file->f_mapping; 94 95 if (!mapping->a_ops->readpage) 96 return -ENOEXEC; 97 file_accessed(file); 98 vma->vm_ops = &ext4_file_vm_ops; 99 vma->vm_flags |= VM_CAN_NONLINEAR; 100 return 0; 101 } 102 103 static int ext4_file_open(struct inode * inode, struct file * filp) 104 { 105 struct super_block *sb = inode->i_sb; 106 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 107 struct vfsmount *mnt = filp->f_path.mnt; 108 struct path path; 109 char buf[64], *cp; 110 111 if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) && 112 !(sb->s_flags & MS_RDONLY))) { 113 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; 114 /* 115 * Sample where the filesystem has been mounted and 116 * store it in the superblock for sysadmin convenience 117 * when trying to sort through large numbers of block 118 * devices or filesystem images. 119 */ 120 memset(buf, 0, sizeof(buf)); 121 path.mnt = mnt; 122 path.dentry = mnt->mnt_root; 123 cp = d_path(&path, buf, sizeof(buf)); 124 if (!IS_ERR(cp)) { 125 memcpy(sbi->s_es->s_last_mounted, cp, 126 sizeof(sbi->s_es->s_last_mounted)); 127 ext4_mark_super_dirty(sb); 128 } 129 } 130 return dquot_file_open(inode, filp); 131 } 132 133 /* 134 * ext4_llseek() copied from generic_file_llseek() to handle both 135 * block-mapped and extent-mapped maxbytes values. This should 136 * otherwise be identical with generic_file_llseek(). 137 */ 138 loff_t ext4_llseek(struct file *file, loff_t offset, int origin) 139 { 140 struct inode *inode = file->f_mapping->host; 141 loff_t maxbytes; 142 143 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 144 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; 145 else 146 maxbytes = inode->i_sb->s_maxbytes; 147 mutex_lock(&inode->i_mutex); 148 switch (origin) { 149 case SEEK_END: 150 offset += inode->i_size; 151 break; 152 case SEEK_CUR: 153 if (offset == 0) { 154 mutex_unlock(&inode->i_mutex); 155 return file->f_pos; 156 } 157 offset += file->f_pos; 158 break; 159 } 160 161 if (offset < 0 || offset > maxbytes) { 162 mutex_unlock(&inode->i_mutex); 163 return -EINVAL; 164 } 165 166 if (offset != file->f_pos) { 167 file->f_pos = offset; 168 file->f_version = 0; 169 } 170 mutex_unlock(&inode->i_mutex); 171 172 return offset; 173 } 174 175 const struct file_operations ext4_file_operations = { 176 .llseek = ext4_llseek, 177 .read = do_sync_read, 178 .write = do_sync_write, 179 .aio_read = generic_file_aio_read, 180 .aio_write = ext4_file_write, 181 .unlocked_ioctl = ext4_ioctl, 182 #ifdef CONFIG_COMPAT 183 .compat_ioctl = ext4_compat_ioctl, 184 #endif 185 .mmap = ext4_file_mmap, 186 .open = ext4_file_open, 187 .release = ext4_release_file, 188 .fsync = ext4_sync_file, 189 .splice_read = generic_file_splice_read, 190 .splice_write = generic_file_splice_write, 191 }; 192 193 const struct inode_operations ext4_file_inode_operations = { 194 .truncate = ext4_truncate, 195 .setattr = ext4_setattr, 196 .getattr = ext4_getattr, 197 #ifdef CONFIG_EXT4_FS_XATTR 198 .setxattr = generic_setxattr, 199 .getxattr = generic_getxattr, 200 .listxattr = ext4_listxattr, 201 .removexattr = generic_removexattr, 202 #endif 203 .check_acl = ext4_check_acl, 204 .fallocate = ext4_fallocate, 205 .fiemap = ext4_fiemap, 206 }; 207 208