ext4: improve llseek error handling for overly large seek offsets
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ext4 / file.c
blob5a5c55ddceef2171e133867969f41dec431f2c39
1 /*
2 * linux/fs/ext4/file.c
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)
9 * from
11 * linux/fs/minix/file.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * ext4 fs regular file handling primitives
17 * 64-bit file support on 64-bit platforms by Jakub Jelinek
18 * (jj@sunsite.ms.mff.cuni.cz)
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"
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.
37 static int ext4_release_file(struct inode *inode, struct file *filp)
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);
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)
48 down_write(&EXT4_I(inode)->i_data_sem);
49 ext4_discard_preallocations(inode);
50 up_write(&EXT4_I(inode)->i_data_sem);
52 if (is_dx(inode) && filp->private_data)
53 ext4_htree_free_dir_info(filp->private_data);
55 return 0;
58 static ssize_t
59 ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
60 unsigned long nr_segs, loff_t pos)
62 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
65 * If we have encountered a bitmap-format file, the size limit
66 * is smaller than s_maxbytes, which is for extent-mapped files.
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);
73 if ((pos > sbi->s_bitmap_maxbytes ||
74 (pos == sbi->s_bitmap_maxbytes && length > 0)))
75 return -EFBIG;
77 if (pos + length > sbi->s_bitmap_maxbytes) {
78 nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
79 sbi->s_bitmap_maxbytes - pos);
83 return generic_file_aio_write(iocb, iov, nr_segs, pos);
86 static const struct vm_operations_struct ext4_file_vm_ops = {
87 .fault = filemap_fault,
88 .page_mkwrite = ext4_page_mkwrite,
91 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
93 struct address_space *mapping = file->f_mapping;
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;
103 static int ext4_file_open(struct inode * inode, struct file * filp)
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;
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;
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.
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);
130 return dquot_file_open(inode, filp);
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().
138 loff_t ext4_llseek(struct file *file, loff_t offset, int origin)
140 struct inode *inode = file->f_mapping->host;
141 loff_t maxbytes;
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;
157 offset += file->f_pos;
158 break;
161 if (offset < 0 || offset > maxbytes) {
162 mutex_unlock(&inode->i_mutex);
163 return -EINVAL;
166 if (offset != file->f_pos) {
167 file->f_pos = offset;
168 file->f_version = 0;
170 mutex_unlock(&inode->i_mutex);
172 return offset;
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,
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,