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1da177e4 LT |
1 | /* |
2 | * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README | |
3 | */ | |
4 | ||
5 | #include <linux/fs.h> | |
6 | #include <linux/reiserfs_fs.h> | |
7 | #include <linux/time.h> | |
8 | #include <asm/uaccess.h> | |
9 | #include <linux/pagemap.h> | |
10 | #include <linux/smp_lock.h> | |
11 | ||
12 | static int reiserfs_unpack (struct inode * inode, struct file * filp); | |
13 | ||
14 | /* | |
15 | ** reiserfs_ioctl - handler for ioctl for inode | |
16 | ** supported commands: | |
17 | ** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect | |
18 | ** and prevent packing file (argument arg has to be non-zero) | |
19 | ** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION | |
20 | ** 3) That's all for a while ... | |
21 | */ | |
22 | int reiserfs_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, | |
23 | unsigned long arg) | |
24 | { | |
25 | unsigned int flags; | |
26 | ||
27 | switch (cmd) { | |
28 | case REISERFS_IOC_UNPACK: | |
29 | if( S_ISREG( inode -> i_mode ) ) { | |
30 | if (arg) | |
31 | return reiserfs_unpack (inode, filp); | |
32 | else | |
33 | return 0; | |
34 | } else | |
35 | return -ENOTTY; | |
36 | /* following two cases are taken from fs/ext2/ioctl.c by Remy | |
37 | Card (card@masi.ibp.fr) */ | |
38 | case REISERFS_IOC_GETFLAGS: | |
869eb76e JM |
39 | if (!reiserfs_attrs (inode->i_sb)) |
40 | return -ENOTTY; | |
41 | ||
1da177e4 LT |
42 | flags = REISERFS_I(inode) -> i_attrs; |
43 | i_attrs_to_sd_attrs( inode, ( __u16 * ) &flags ); | |
44 | return put_user(flags, (int __user *) arg); | |
45 | case REISERFS_IOC_SETFLAGS: { | |
869eb76e JM |
46 | if (!reiserfs_attrs (inode->i_sb)) |
47 | return -ENOTTY; | |
48 | ||
1da177e4 LT |
49 | if (IS_RDONLY(inode)) |
50 | return -EROFS; | |
51 | ||
52 | if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) | |
53 | return -EPERM; | |
54 | ||
55 | if (get_user(flags, (int __user *) arg)) | |
56 | return -EFAULT; | |
57 | ||
58 | if ( ( ( flags ^ REISERFS_I(inode) -> i_attrs) & ( REISERFS_IMMUTABLE_FL | REISERFS_APPEND_FL)) && | |
59 | !capable( CAP_LINUX_IMMUTABLE ) ) | |
60 | return -EPERM; | |
61 | ||
62 | if( ( flags & REISERFS_NOTAIL_FL ) && | |
63 | S_ISREG( inode -> i_mode ) ) { | |
64 | int result; | |
65 | ||
66 | result = reiserfs_unpack( inode, filp ); | |
67 | if( result ) | |
68 | return result; | |
69 | } | |
70 | sd_attrs_to_i_attrs( flags, inode ); | |
71 | REISERFS_I(inode) -> i_attrs = flags; | |
72 | inode->i_ctime = CURRENT_TIME_SEC; | |
73 | mark_inode_dirty(inode); | |
74 | return 0; | |
75 | } | |
76 | case REISERFS_IOC_GETVERSION: | |
77 | return put_user(inode->i_generation, (int __user *) arg); | |
78 | case REISERFS_IOC_SETVERSION: | |
79 | if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) | |
80 | return -EPERM; | |
81 | if (IS_RDONLY(inode)) | |
82 | return -EROFS; | |
83 | if (get_user(inode->i_generation, (int __user *) arg)) | |
84 | return -EFAULT; | |
85 | inode->i_ctime = CURRENT_TIME_SEC; | |
86 | mark_inode_dirty(inode); | |
87 | return 0; | |
88 | default: | |
89 | return -ENOTTY; | |
90 | } | |
91 | } | |
92 | ||
93 | /* | |
94 | ** reiserfs_unpack | |
95 | ** Function try to convert tail from direct item into indirect. | |
96 | ** It set up nopack attribute in the REISERFS_I(inode)->nopack | |
97 | */ | |
98 | static int reiserfs_unpack (struct inode * inode, struct file * filp) | |
99 | { | |
100 | int retval = 0; | |
101 | int index ; | |
102 | struct page *page ; | |
103 | struct address_space *mapping ; | |
104 | unsigned long write_from ; | |
105 | unsigned long blocksize = inode->i_sb->s_blocksize ; | |
106 | ||
107 | if (inode->i_size == 0) { | |
108 | REISERFS_I(inode)->i_flags |= i_nopack_mask; | |
109 | return 0 ; | |
110 | } | |
111 | /* ioctl already done */ | |
112 | if (REISERFS_I(inode)->i_flags & i_nopack_mask) { | |
113 | return 0 ; | |
114 | } | |
115 | reiserfs_write_lock(inode->i_sb); | |
116 | ||
117 | /* we need to make sure nobody is changing the file size beneath | |
118 | ** us | |
119 | */ | |
120 | down(&inode->i_sem) ; | |
121 | ||
122 | write_from = inode->i_size & (blocksize - 1) ; | |
123 | /* if we are on a block boundary, we are already unpacked. */ | |
124 | if ( write_from == 0) { | |
125 | REISERFS_I(inode)->i_flags |= i_nopack_mask; | |
126 | goto out ; | |
127 | } | |
128 | ||
129 | /* we unpack by finding the page with the tail, and calling | |
130 | ** reiserfs_prepare_write on that page. This will force a | |
131 | ** reiserfs_get_block to unpack the tail for us. | |
132 | */ | |
133 | index = inode->i_size >> PAGE_CACHE_SHIFT ; | |
134 | mapping = inode->i_mapping ; | |
135 | page = grab_cache_page(mapping, index) ; | |
136 | retval = -ENOMEM; | |
137 | if (!page) { | |
138 | goto out ; | |
139 | } | |
140 | retval = mapping->a_ops->prepare_write(NULL, page, write_from, write_from) ; | |
141 | if (retval) | |
142 | goto out_unlock ; | |
143 | ||
144 | /* conversion can change page contents, must flush */ | |
145 | flush_dcache_page(page) ; | |
146 | retval = mapping->a_ops->commit_write(NULL, page, write_from, write_from) ; | |
147 | REISERFS_I(inode)->i_flags |= i_nopack_mask; | |
148 | ||
149 | out_unlock: | |
150 | unlock_page(page) ; | |
151 | page_cache_release(page) ; | |
152 | ||
153 | out: | |
154 | up(&inode->i_sem) ; | |
155 | reiserfs_write_unlock(inode->i_sb); | |
156 | return retval; | |
157 | } |