Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
[linux-2.6] / 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 "ext4.h"
25 #include "ext4_jbd2.h"
26 #include "xattr.h"
27 #include "acl.h"
28
29 /*
30  * Called when an inode is released. Note that this is different
31  * from ext4_file_open: open gets called at every open, but release
32  * gets called only when /all/ the files are closed.
33  */
34 static int ext4_release_file(struct inode *inode, struct file *filp)
35 {
36         if (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) {
37                 ext4_alloc_da_blocks(inode);
38                 EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE;
39         }
40         /* if we are the last writer on the inode, drop the block reservation */
41         if ((filp->f_mode & FMODE_WRITE) &&
42                         (atomic_read(&inode->i_writecount) == 1) &&
43                         !EXT4_I(inode)->i_reserved_data_blocks)
44         {
45                 down_write(&EXT4_I(inode)->i_data_sem);
46                 ext4_discard_preallocations(inode);
47                 up_write(&EXT4_I(inode)->i_data_sem);
48         }
49         if (is_dx(inode) && filp->private_data)
50                 ext4_htree_free_dir_info(filp->private_data);
51
52         return 0;
53 }
54
55 static ssize_t
56 ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
57                 unsigned long nr_segs, loff_t pos)
58 {
59         struct file *file = iocb->ki_filp;
60         struct inode *inode = file->f_path.dentry->d_inode;
61         ssize_t ret;
62         int err;
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_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
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                         return -EFBIG;
75
76                 if (pos + length > sbi->s_bitmap_maxbytes) {
77                         nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
78                                               sbi->s_bitmap_maxbytes - pos);
79                 }
80         }
81
82         ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
83         /*
84          * Skip flushing if there was an error, or if nothing was written.
85          */
86         if (ret <= 0)
87                 return ret;
88
89         /*
90          * If the inode is IS_SYNC, or is O_SYNC and we are doing data
91          * journalling then we need to make sure that we force the transaction
92          * to disk to keep all metadata uptodate synchronously.
93          */
94         if (file->f_flags & O_SYNC) {
95                 /*
96                  * If we are non-data-journaled, then the dirty data has
97                  * already been flushed to backing store by generic_osync_inode,
98                  * and the inode has been flushed too if there have been any
99                  * modifications other than mere timestamp updates.
100                  *
101                  * Open question --- do we care about flushing timestamps too
102                  * if the inode is IS_SYNC?
103                  */
104                 if (!ext4_should_journal_data(inode))
105                         return ret;
106
107                 goto force_commit;
108         }
109
110         /*
111          * So we know that there has been no forced data flush.  If the inode
112          * is marked IS_SYNC, we need to force one ourselves.
113          */
114         if (!IS_SYNC(inode))
115                 return ret;
116
117         /*
118          * Open question #2 --- should we force data to disk here too?  If we
119          * don't, the only impact is that data=writeback filesystems won't
120          * flush data to disk automatically on IS_SYNC, only metadata (but
121          * historically, that is what ext2 has done.)
122          */
123
124 force_commit:
125         err = ext4_force_commit(inode->i_sb);
126         if (err)
127                 return err;
128         return ret;
129 }
130
131 static struct vm_operations_struct ext4_file_vm_ops = {
132         .fault          = filemap_fault,
133         .page_mkwrite   = ext4_page_mkwrite,
134 };
135
136 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
137 {
138         struct address_space *mapping = file->f_mapping;
139
140         if (!mapping->a_ops->readpage)
141                 return -ENOEXEC;
142         file_accessed(file);
143         vma->vm_ops = &ext4_file_vm_ops;
144         vma->vm_flags |= VM_CAN_NONLINEAR;
145         return 0;
146 }
147
148 const struct file_operations ext4_file_operations = {
149         .llseek         = generic_file_llseek,
150         .read           = do_sync_read,
151         .write          = do_sync_write,
152         .aio_read       = generic_file_aio_read,
153         .aio_write      = ext4_file_write,
154         .unlocked_ioctl = ext4_ioctl,
155 #ifdef CONFIG_COMPAT
156         .compat_ioctl   = ext4_compat_ioctl,
157 #endif
158         .mmap           = ext4_file_mmap,
159         .open           = generic_file_open,
160         .release        = ext4_release_file,
161         .fsync          = ext4_sync_file,
162         .splice_read    = generic_file_splice_read,
163         .splice_write   = generic_file_splice_write,
164 };
165
166 const struct inode_operations ext4_file_inode_operations = {
167         .truncate       = ext4_truncate,
168         .setattr        = ext4_setattr,
169         .getattr        = ext4_getattr,
170 #ifdef CONFIG_EXT4_FS_XATTR
171         .setxattr       = generic_setxattr,
172         .getxattr       = generic_getxattr,
173         .listxattr      = ext4_listxattr,
174         .removexattr    = generic_removexattr,
175 #endif
176         .permission     = ext4_permission,
177         .fallocate      = ext4_fallocate,
178         .fiemap         = ext4_fiemap,
179 };
180