Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / fs / ext4 / file.c
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 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