Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * fs/libfs.c |
| 3 | * Library for filesystems writers. |
| 4 | */ |
| 5 | |
Fabian Frederick | ac13a82 | 2014-06-04 16:06:27 -0700 | [diff] [blame] | 6 | #include <linux/blkdev.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 7 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/pagemap.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 9 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/mount.h> |
| 11 | #include <linux/vfs.h> |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 12 | #include <linux/quotaops.h> |
Ingo Molnar | 7cf34c7 | 2006-03-23 03:00:36 -0800 | [diff] [blame] | 13 | #include <linux/mutex.h> |
Al Viro | 87dc800 | 2013-09-16 10:30:04 -0400 | [diff] [blame] | 14 | #include <linux/namei.h> |
Christoph Hellwig | 2596110 | 2007-10-21 16:42:05 -0700 | [diff] [blame] | 15 | #include <linux/exportfs.h> |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 16 | #include <linux/writeback.h> |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 17 | #include <linux/buffer_head.h> /* sync_mapping_buffers */ |
Ingo Molnar | 7cf34c7 | 2006-03-23 03:00:36 -0800 | [diff] [blame] | 18 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <asm/uaccess.h> |
| 20 | |
Al Viro | a4464db | 2011-07-07 15:03:58 -0400 | [diff] [blame] | 21 | #include "internal.h" |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | int simple_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| 24 | struct kstat *stat) |
| 25 | { |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 26 | struct inode *inode = d_inode(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | generic_fillattr(inode, stat); |
| 28 | stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9); |
| 29 | return 0; |
| 30 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 31 | EXPORT_SYMBOL(simple_getattr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 33 | int simple_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 35 | buf->f_type = dentry->d_sb->s_magic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | buf->f_bsize = PAGE_CACHE_SIZE; |
| 37 | buf->f_namelen = NAME_MAX; |
| 38 | return 0; |
| 39 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 40 | EXPORT_SYMBOL(simple_statfs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
| 42 | /* |
| 43 | * Retaining negative dentries for an in-memory filesystem just wastes |
| 44 | * memory and lookup time: arrange for them to be deleted immediately. |
| 45 | */ |
Al Viro | b26d4cd | 2013-10-25 18:47:37 -0400 | [diff] [blame] | 46 | int always_delete_dentry(const struct dentry *dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | { |
| 48 | return 1; |
| 49 | } |
Al Viro | b26d4cd | 2013-10-25 18:47:37 -0400 | [diff] [blame] | 50 | EXPORT_SYMBOL(always_delete_dentry); |
| 51 | |
| 52 | const struct dentry_operations simple_dentry_operations = { |
| 53 | .d_delete = always_delete_dentry, |
| 54 | }; |
| 55 | EXPORT_SYMBOL(simple_dentry_operations); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
| 57 | /* |
| 58 | * Lookup the data. This is trivial - if the dentry didn't already |
| 59 | * exist, we know it is negative. Set d_op to delete negative dentries. |
| 60 | */ |
Al Viro | 00cd8dd | 2012-06-10 17:13:09 -0400 | [diff] [blame] | 61 | struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | if (dentry->d_name.len > NAME_MAX) |
| 64 | return ERR_PTR(-ENAMETOOLONG); |
Al Viro | 74931da | 2013-07-14 17:43:25 +0400 | [diff] [blame] | 65 | if (!dentry->d_sb->s_d_op) |
| 66 | d_set_d_op(dentry, &simple_dentry_operations); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | d_add(dentry, NULL); |
| 68 | return NULL; |
| 69 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 70 | EXPORT_SYMBOL(simple_lookup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | int dcache_dir_open(struct inode *inode, struct file *file) |
| 73 | { |
Linus Torvalds | 26fe575 | 2012-05-10 13:14:12 -0700 | [diff] [blame] | 74 | static struct qstr cursor_name = QSTR_INIT(".", 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 76 | file->private_data = d_alloc(file->f_path.dentry, &cursor_name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | return file->private_data ? 0 : -ENOMEM; |
| 79 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 80 | EXPORT_SYMBOL(dcache_dir_open); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | |
| 82 | int dcache_dir_close(struct inode *inode, struct file *file) |
| 83 | { |
| 84 | dput(file->private_data); |
| 85 | return 0; |
| 86 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 87 | EXPORT_SYMBOL(dcache_dir_close); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 89 | loff_t dcache_dir_lseek(struct file *file, loff_t offset, int whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | { |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 91 | struct dentry *dentry = file->f_path.dentry; |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 92 | mutex_lock(&d_inode(dentry)->i_mutex); |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 93 | switch (whence) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | case 1: |
| 95 | offset += file->f_pos; |
| 96 | case 0: |
| 97 | if (offset >= 0) |
| 98 | break; |
| 99 | default: |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 100 | mutex_unlock(&d_inode(dentry)->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | return -EINVAL; |
| 102 | } |
| 103 | if (offset != file->f_pos) { |
| 104 | file->f_pos = offset; |
| 105 | if (file->f_pos >= 2) { |
| 106 | struct list_head *p; |
| 107 | struct dentry *cursor = file->private_data; |
| 108 | loff_t n = file->f_pos - 2; |
| 109 | |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 110 | spin_lock(&dentry->d_lock); |
| 111 | /* d_lock not required for cursor */ |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 112 | list_del(&cursor->d_child); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 113 | p = dentry->d_subdirs.next; |
| 114 | while (n && p != &dentry->d_subdirs) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | struct dentry *next; |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 116 | next = list_entry(p, struct dentry, d_child); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 117 | spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); |
Nick Piggin | da50295 | 2011-01-07 17:49:33 +1100 | [diff] [blame] | 118 | if (simple_positive(next)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | n--; |
Nick Piggin | da50295 | 2011-01-07 17:49:33 +1100 | [diff] [blame] | 120 | spin_unlock(&next->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | p = p->next; |
| 122 | } |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 123 | list_add_tail(&cursor->d_child, p); |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 124 | spin_unlock(&dentry->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | } |
| 126 | } |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 127 | mutex_unlock(&d_inode(dentry)->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | return offset; |
| 129 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 130 | EXPORT_SYMBOL(dcache_dir_lseek); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | |
| 132 | /* Relationship between i_mode and the DT_xxx types */ |
| 133 | static inline unsigned char dt_type(struct inode *inode) |
| 134 | { |
| 135 | return (inode->i_mode >> 12) & 15; |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * Directory is locked and all positive dentries in it are safe, since |
| 140 | * for ramfs-type trees they can't go away without unlink() or rmdir(), |
| 141 | * both impossible due to the lock on directory. |
| 142 | */ |
| 143 | |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 144 | int dcache_readdir(struct file *file, struct dir_context *ctx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | { |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 146 | struct dentry *dentry = file->f_path.dentry; |
| 147 | struct dentry *cursor = file->private_data; |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 148 | struct list_head *p, *q = &cursor->d_child; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 150 | if (!dir_emit_dots(file, ctx)) |
| 151 | return 0; |
| 152 | spin_lock(&dentry->d_lock); |
| 153 | if (ctx->pos == 2) |
| 154 | list_move(q, &dentry->d_subdirs); |
Akinobu Mita | 1bfba4e | 2006-06-26 00:24:40 -0700 | [diff] [blame] | 155 | |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 156 | for (p = q->next; p != &dentry->d_subdirs; p = p->next) { |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 157 | struct dentry *next = list_entry(p, struct dentry, d_child); |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 158 | spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); |
| 159 | if (!simple_positive(next)) { |
| 160 | spin_unlock(&next->d_lock); |
| 161 | continue; |
| 162 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 164 | spin_unlock(&next->d_lock); |
| 165 | spin_unlock(&dentry->d_lock); |
| 166 | if (!dir_emit(ctx, next->d_name.name, next->d_name.len, |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 167 | d_inode(next)->i_ino, dt_type(d_inode(next)))) |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 168 | return 0; |
| 169 | spin_lock(&dentry->d_lock); |
| 170 | spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); |
| 171 | /* next is still alive */ |
| 172 | list_move(q, p); |
| 173 | spin_unlock(&next->d_lock); |
| 174 | p = q; |
| 175 | ctx->pos++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | } |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 177 | spin_unlock(&dentry->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | return 0; |
| 179 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 180 | EXPORT_SYMBOL(dcache_readdir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
| 182 | ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos) |
| 183 | { |
| 184 | return -EISDIR; |
| 185 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 186 | EXPORT_SYMBOL(generic_read_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 188 | const struct file_operations simple_dir_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | .open = dcache_dir_open, |
| 190 | .release = dcache_dir_close, |
| 191 | .llseek = dcache_dir_lseek, |
| 192 | .read = generic_read_dir, |
Al Viro | 5f99f4e | 2013-05-15 20:23:06 -0400 | [diff] [blame] | 193 | .iterate = dcache_readdir, |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 194 | .fsync = noop_fsync, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | }; |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 196 | EXPORT_SYMBOL(simple_dir_operations); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 198 | const struct inode_operations simple_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | .lookup = simple_lookup, |
| 200 | }; |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 201 | EXPORT_SYMBOL(simple_dir_inode_operations); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 203 | static const struct super_operations simple_super_operations = { |
| 204 | .statfs = simple_statfs, |
| 205 | }; |
| 206 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | /* |
| 208 | * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that |
| 209 | * will never be mountable) |
| 210 | */ |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 211 | struct dentry *mount_pseudo(struct file_system_type *fs_type, char *name, |
Al Viro | c74a1cb | 2011-01-12 16:59:34 -0500 | [diff] [blame] | 212 | const struct super_operations *ops, |
| 213 | const struct dentry_operations *dops, unsigned long magic) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | { |
David Howells | 9249e17 | 2012-06-25 12:55:37 +0100 | [diff] [blame] | 215 | struct super_block *s; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | struct dentry *dentry; |
| 217 | struct inode *root; |
Linus Torvalds | 26fe575 | 2012-05-10 13:14:12 -0700 | [diff] [blame] | 218 | struct qstr d_name = QSTR_INIT(name, strlen(name)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | |
David Howells | 9249e17 | 2012-06-25 12:55:37 +0100 | [diff] [blame] | 220 | s = sget(fs_type, NULL, set_anon_super, MS_NOUSER, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | if (IS_ERR(s)) |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 222 | return ERR_CAST(s); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
Jeff Layton | 89a4eb4 | 2009-08-18 14:11:08 -0700 | [diff] [blame] | 224 | s->s_maxbytes = MAX_LFS_FILESIZE; |
Alex Nixon | 3971e1a | 2008-07-29 22:33:03 -0700 | [diff] [blame] | 225 | s->s_blocksize = PAGE_SIZE; |
| 226 | s->s_blocksize_bits = PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | s->s_magic = magic; |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 228 | s->s_op = ops ? ops : &simple_super_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | s->s_time_gran = 1; |
| 230 | root = new_inode(s); |
| 231 | if (!root) |
| 232 | goto Enomem; |
Jeff Layton | 1a1c9bb | 2007-05-08 00:32:31 -0700 | [diff] [blame] | 233 | /* |
| 234 | * since this is the first inode, make it number 1. New inodes created |
| 235 | * after this must take care not to collide with it (by passing |
| 236 | * max_reserved of 1 to iunique). |
| 237 | */ |
| 238 | root->i_ino = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; |
Al Viro | a4464db | 2011-07-07 15:03:58 -0400 | [diff] [blame] | 241 | dentry = __d_alloc(s, &d_name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | if (!dentry) { |
| 243 | iput(root); |
| 244 | goto Enomem; |
| 245 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | d_instantiate(dentry, root); |
| 247 | s->s_root = dentry; |
Al Viro | c74a1cb | 2011-01-12 16:59:34 -0500 | [diff] [blame] | 248 | s->s_d_op = dops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | s->s_flags |= MS_ACTIVE; |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 250 | return dget(s->s_root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
| 252 | Enomem: |
Al Viro | 6f5bbff | 2009-05-06 01:34:22 -0400 | [diff] [blame] | 253 | deactivate_locked_super(s); |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 254 | return ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 256 | EXPORT_SYMBOL(mount_pseudo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | |
Stephen Boyd | 20955e8 | 2012-04-05 14:25:09 -0700 | [diff] [blame] | 258 | int simple_open(struct inode *inode, struct file *file) |
| 259 | { |
| 260 | if (inode->i_private) |
| 261 | file->private_data = inode->i_private; |
| 262 | return 0; |
| 263 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 264 | EXPORT_SYMBOL(simple_open); |
Stephen Boyd | 20955e8 | 2012-04-05 14:25:09 -0700 | [diff] [blame] | 265 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 267 | { |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 268 | struct inode *inode = d_inode(old_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | |
| 270 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 271 | inc_nlink(inode); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 272 | ihold(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | dget(dentry); |
| 274 | d_instantiate(dentry, inode); |
| 275 | return 0; |
| 276 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 277 | EXPORT_SYMBOL(simple_link); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | int simple_empty(struct dentry *dentry) |
| 280 | { |
| 281 | struct dentry *child; |
| 282 | int ret = 0; |
| 283 | |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 284 | spin_lock(&dentry->d_lock); |
Al Viro | 946e51f | 2014-10-26 19:19:16 -0400 | [diff] [blame] | 285 | list_for_each_entry(child, &dentry->d_subdirs, d_child) { |
Nick Piggin | da50295 | 2011-01-07 17:49:33 +1100 | [diff] [blame] | 286 | spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); |
| 287 | if (simple_positive(child)) { |
| 288 | spin_unlock(&child->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | goto out; |
Nick Piggin | da50295 | 2011-01-07 17:49:33 +1100 | [diff] [blame] | 290 | } |
| 291 | spin_unlock(&child->d_lock); |
| 292 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | ret = 1; |
| 294 | out: |
Nick Piggin | 2fd6b7f | 2011-01-07 17:49:34 +1100 | [diff] [blame] | 295 | spin_unlock(&dentry->d_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | return ret; |
| 297 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 298 | EXPORT_SYMBOL(simple_empty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | |
| 300 | int simple_unlink(struct inode *dir, struct dentry *dentry) |
| 301 | { |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 302 | struct inode *inode = d_inode(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | |
| 304 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 305 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | dput(dentry); |
| 307 | return 0; |
| 308 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 309 | EXPORT_SYMBOL(simple_unlink); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | |
| 311 | int simple_rmdir(struct inode *dir, struct dentry *dentry) |
| 312 | { |
| 313 | if (!simple_empty(dentry)) |
| 314 | return -ENOTEMPTY; |
| 315 | |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 316 | drop_nlink(d_inode(dentry)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | simple_unlink(dir, dentry); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 318 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | return 0; |
| 320 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 321 | EXPORT_SYMBOL(simple_rmdir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | |
| 323 | int simple_rename(struct inode *old_dir, struct dentry *old_dentry, |
| 324 | struct inode *new_dir, struct dentry *new_dentry) |
| 325 | { |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 326 | struct inode *inode = d_inode(old_dentry); |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 327 | int they_are_dirs = d_is_dir(old_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | |
| 329 | if (!simple_empty(new_dentry)) |
| 330 | return -ENOTEMPTY; |
| 331 | |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 332 | if (d_really_is_positive(new_dentry)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | simple_unlink(new_dir, new_dentry); |
Al Viro | 841590c | 2011-07-21 15:49:09 -0400 | [diff] [blame] | 334 | if (they_are_dirs) { |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 335 | drop_nlink(d_inode(new_dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 336 | drop_nlink(old_dir); |
Al Viro | 841590c | 2011-07-21 15:49:09 -0400 | [diff] [blame] | 337 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 339 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 340 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | } |
| 342 | |
| 343 | old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = |
| 344 | new_dir->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 345 | |
| 346 | return 0; |
| 347 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 348 | EXPORT_SYMBOL(simple_rename); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 350 | /** |
Christoph Hellwig | eef2380 | 2010-06-04 11:30:01 +0200 | [diff] [blame] | 351 | * simple_setattr - setattr for simple filesystem |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 352 | * @dentry: dentry |
| 353 | * @iattr: iattr structure |
| 354 | * |
| 355 | * Returns 0 on success, -error on failure. |
| 356 | * |
Christoph Hellwig | eef2380 | 2010-06-04 11:30:01 +0200 | [diff] [blame] | 357 | * simple_setattr is a simple ->setattr implementation without a proper |
| 358 | * implementation of size changes. |
| 359 | * |
| 360 | * It can either be used for in-memory filesystems or special files |
| 361 | * on simple regular filesystems. Anything that needs to change on-disk |
| 362 | * or wire state on size changes needs its own setattr method. |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 363 | */ |
| 364 | int simple_setattr(struct dentry *dentry, struct iattr *iattr) |
| 365 | { |
David Howells | dea655c | 2015-03-17 22:26:15 +0000 | [diff] [blame] | 366 | struct inode *inode = d_inode(dentry); |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 367 | int error; |
| 368 | |
| 369 | error = inode_change_ok(inode, iattr); |
| 370 | if (error) |
| 371 | return error; |
| 372 | |
Christoph Hellwig | 2c27c65 | 2010-06-04 11:30:04 +0200 | [diff] [blame] | 373 | if (iattr->ia_valid & ATTR_SIZE) |
| 374 | truncate_setsize(inode, iattr->ia_size); |
Christoph Hellwig | 6a1a90a | 2010-06-04 11:30:00 +0200 | [diff] [blame] | 375 | setattr_copy(inode, iattr); |
Christoph Hellwig | eef2380 | 2010-06-04 11:30:01 +0200 | [diff] [blame] | 376 | mark_inode_dirty(inode); |
| 377 | return 0; |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 378 | } |
| 379 | EXPORT_SYMBOL(simple_setattr); |
| 380 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | int simple_readpage(struct file *file, struct page *page) |
| 382 | { |
Pekka J Enberg | c0d92cb | 2006-09-29 01:59:09 -0700 | [diff] [blame] | 383 | clear_highpage(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | flush_dcache_page(page); |
| 385 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | unlock_page(page); |
| 387 | return 0; |
| 388 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 389 | EXPORT_SYMBOL(simple_readpage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 391 | int simple_write_begin(struct file *file, struct address_space *mapping, |
| 392 | loff_t pos, unsigned len, unsigned flags, |
| 393 | struct page **pagep, void **fsdata) |
| 394 | { |
| 395 | struct page *page; |
| 396 | pgoff_t index; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 397 | |
| 398 | index = pos >> PAGE_CACHE_SHIFT; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 399 | |
Nick Piggin | 54566b2 | 2009-01-04 12:00:53 -0800 | [diff] [blame] | 400 | page = grab_cache_page_write_begin(mapping, index, flags); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 401 | if (!page) |
| 402 | return -ENOMEM; |
| 403 | |
| 404 | *pagep = page; |
| 405 | |
Boaz Harrosh | 193cf4b | 2010-01-12 16:18:08 +0200 | [diff] [blame] | 406 | if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) { |
| 407 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| 408 | |
| 409 | zero_user_segments(page, 0, from, from + len, PAGE_CACHE_SIZE); |
| 410 | } |
| 411 | return 0; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 412 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 413 | EXPORT_SYMBOL(simple_write_begin); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 414 | |
Boaz Harrosh | ad2a722f | 2010-01-12 15:13:47 +0200 | [diff] [blame] | 415 | /** |
| 416 | * simple_write_end - .write_end helper for non-block-device FSes |
| 417 | * @available: See .write_end of address_space_operations |
| 418 | * @file: " |
| 419 | * @mapping: " |
| 420 | * @pos: " |
| 421 | * @len: " |
| 422 | * @copied: " |
| 423 | * @page: " |
| 424 | * @fsdata: " |
| 425 | * |
| 426 | * simple_write_end does the minimum needed for updating a page after writing is |
| 427 | * done. It has the same API signature as the .write_end of |
| 428 | * address_space_operations vector. So it can just be set onto .write_end for |
| 429 | * FSes that don't need any other processing. i_mutex is assumed to be held. |
| 430 | * Block based filesystems should use generic_write_end(). |
| 431 | * NOTE: Even though i_size might get updated by this function, mark_inode_dirty |
| 432 | * is not called, so a filesystem that actually does store data in .write_inode |
| 433 | * should extend on what's done here with a call to mark_inode_dirty() in the |
| 434 | * case that i_size has changed. |
| 435 | */ |
| 436 | int simple_write_end(struct file *file, struct address_space *mapping, |
| 437 | loff_t pos, unsigned len, unsigned copied, |
| 438 | struct page *page, void *fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | { |
| 440 | struct inode *inode = page->mapping->host; |
Boaz Harrosh | ad2a722f | 2010-01-12 15:13:47 +0200 | [diff] [blame] | 441 | loff_t last_pos = pos + copied; |
| 442 | |
| 443 | /* zero the stale part of the page if we did a short copy */ |
| 444 | if (copied < len) { |
| 445 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| 446 | |
| 447 | zero_user(page, from + copied, len - copied); |
| 448 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | |
Nick Piggin | 955eff5 | 2007-02-20 13:58:08 -0800 | [diff] [blame] | 450 | if (!PageUptodate(page)) |
| 451 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | /* |
| 453 | * No need to use i_size_read() here, the i_size |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 454 | * cannot change under us because we hold the i_mutex. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | */ |
Boaz Harrosh | ad2a722f | 2010-01-12 15:13:47 +0200 | [diff] [blame] | 456 | if (last_pos > inode->i_size) |
| 457 | i_size_write(inode, last_pos); |
| 458 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | set_page_dirty(page); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 460 | unlock_page(page); |
| 461 | page_cache_release(page); |
| 462 | |
| 463 | return copied; |
| 464 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 465 | EXPORT_SYMBOL(simple_write_end); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 466 | |
Jeff Layton | 1a1c9bb | 2007-05-08 00:32:31 -0700 | [diff] [blame] | 467 | /* |
| 468 | * the inodes created here are not hashed. If you use iunique to generate |
| 469 | * unique inode values later for this filesystem, then you must take care |
| 470 | * to pass it an appropriate max_reserved value to avoid collisions. |
| 471 | */ |
Roberto Sassu | 7d683a0 | 2010-06-03 11:58:28 +0200 | [diff] [blame] | 472 | int simple_fill_super(struct super_block *s, unsigned long magic, |
| 473 | struct tree_descr *files) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | struct inode *inode; |
| 476 | struct dentry *root; |
| 477 | struct dentry *dentry; |
| 478 | int i; |
| 479 | |
| 480 | s->s_blocksize = PAGE_CACHE_SIZE; |
| 481 | s->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 482 | s->s_magic = magic; |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 483 | s->s_op = &simple_super_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | s->s_time_gran = 1; |
| 485 | |
| 486 | inode = new_inode(s); |
| 487 | if (!inode) |
| 488 | return -ENOMEM; |
Jeff Layton | 1a1c9bb | 2007-05-08 00:32:31 -0700 | [diff] [blame] | 489 | /* |
| 490 | * because the root inode is 1, the files array must not contain an |
| 491 | * entry at index 1 |
| 492 | */ |
| 493 | inode->i_ino = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | inode->i_mode = S_IFDIR | 0755; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 496 | inode->i_op = &simple_dir_inode_operations; |
| 497 | inode->i_fop = &simple_dir_operations; |
Miklos Szeredi | bfe8684 | 2011-10-28 14:13:29 +0200 | [diff] [blame] | 498 | set_nlink(inode, 2); |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 499 | root = d_make_root(inode); |
| 500 | if (!root) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | for (i = 0; !files->name || files->name[0]; i++, files++) { |
| 503 | if (!files->name) |
| 504 | continue; |
Jeff Layton | 1a1c9bb | 2007-05-08 00:32:31 -0700 | [diff] [blame] | 505 | |
| 506 | /* warn if it tries to conflict with the root inode */ |
| 507 | if (unlikely(i == 1)) |
| 508 | printk(KERN_WARNING "%s: %s passed in a files array" |
| 509 | "with an index of 1!\n", __func__, |
| 510 | s->s_type->name); |
| 511 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | dentry = d_alloc_name(root, files->name); |
| 513 | if (!dentry) |
| 514 | goto out; |
| 515 | inode = new_inode(s); |
Konstantin Khlebnikov | 32096ea | 2011-11-01 16:12:33 +0300 | [diff] [blame] | 516 | if (!inode) { |
| 517 | dput(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | goto out; |
Konstantin Khlebnikov | 32096ea | 2011-11-01 16:12:33 +0300 | [diff] [blame] | 519 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | inode->i_mode = S_IFREG | files->mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 522 | inode->i_fop = files->ops; |
| 523 | inode->i_ino = i; |
| 524 | d_add(dentry, inode); |
| 525 | } |
| 526 | s->s_root = root; |
| 527 | return 0; |
| 528 | out: |
| 529 | d_genocide(root); |
Al Viro | 640946f | 2012-04-02 19:22:25 -0400 | [diff] [blame] | 530 | shrink_dcache_parent(root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | dput(root); |
| 532 | return -ENOMEM; |
| 533 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 534 | EXPORT_SYMBOL(simple_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | |
| 536 | static DEFINE_SPINLOCK(pin_fs_lock); |
| 537 | |
Trond Myklebust | 1f5ce9e | 2006-06-09 09:34:16 -0400 | [diff] [blame] | 538 | int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | { |
| 540 | struct vfsmount *mnt = NULL; |
| 541 | spin_lock(&pin_fs_lock); |
| 542 | if (unlikely(!*mount)) { |
| 543 | spin_unlock(&pin_fs_lock); |
Al Viro | 2452992 | 2012-03-17 02:13:52 -0400 | [diff] [blame] | 544 | mnt = vfs_kern_mount(type, MS_KERNMOUNT, type->name, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | if (IS_ERR(mnt)) |
| 546 | return PTR_ERR(mnt); |
| 547 | spin_lock(&pin_fs_lock); |
| 548 | if (!*mount) |
| 549 | *mount = mnt; |
| 550 | } |
| 551 | mntget(*mount); |
| 552 | ++*count; |
| 553 | spin_unlock(&pin_fs_lock); |
| 554 | mntput(mnt); |
| 555 | return 0; |
| 556 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 557 | EXPORT_SYMBOL(simple_pin_fs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | |
| 559 | void simple_release_fs(struct vfsmount **mount, int *count) |
| 560 | { |
| 561 | struct vfsmount *mnt; |
| 562 | spin_lock(&pin_fs_lock); |
| 563 | mnt = *mount; |
| 564 | if (!--*count) |
| 565 | *mount = NULL; |
| 566 | spin_unlock(&pin_fs_lock); |
| 567 | mntput(mnt); |
| 568 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 569 | EXPORT_SYMBOL(simple_release_fs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | |
Akinobu Mita | 6d1029b | 2008-07-04 09:59:51 -0700 | [diff] [blame] | 571 | /** |
| 572 | * simple_read_from_buffer - copy data from the buffer to user space |
| 573 | * @to: the user space buffer to read to |
| 574 | * @count: the maximum number of bytes to read |
| 575 | * @ppos: the current position in the buffer |
| 576 | * @from: the buffer to read from |
| 577 | * @available: the size of the buffer |
| 578 | * |
| 579 | * The simple_read_from_buffer() function reads up to @count bytes from the |
| 580 | * buffer @from at offset @ppos into the user space address starting at @to. |
| 581 | * |
| 582 | * On success, the number of bytes read is returned and the offset @ppos is |
| 583 | * advanced by this number, or negative value is returned on error. |
| 584 | **/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, |
| 586 | const void *from, size_t available) |
| 587 | { |
| 588 | loff_t pos = *ppos; |
Steven Rostedt | 14be274 | 2009-09-18 13:05:42 -0700 | [diff] [blame] | 589 | size_t ret; |
| 590 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | if (pos < 0) |
| 592 | return -EINVAL; |
Steven Rostedt | 14be274 | 2009-09-18 13:05:42 -0700 | [diff] [blame] | 593 | if (pos >= available || !count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | return 0; |
| 595 | if (count > available - pos) |
| 596 | count = available - pos; |
Steven Rostedt | 14be274 | 2009-09-18 13:05:42 -0700 | [diff] [blame] | 597 | ret = copy_to_user(to, from + pos, count); |
| 598 | if (ret == count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | return -EFAULT; |
Steven Rostedt | 14be274 | 2009-09-18 13:05:42 -0700 | [diff] [blame] | 600 | count -= ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | *ppos = pos + count; |
| 602 | return count; |
| 603 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 604 | EXPORT_SYMBOL(simple_read_from_buffer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | |
Akinobu Mita | 6d1029b | 2008-07-04 09:59:51 -0700 | [diff] [blame] | 606 | /** |
Jiri Slaby | 6a727b4 | 2010-05-01 23:51:22 +0200 | [diff] [blame] | 607 | * simple_write_to_buffer - copy data from user space to the buffer |
| 608 | * @to: the buffer to write to |
| 609 | * @available: the size of the buffer |
| 610 | * @ppos: the current position in the buffer |
| 611 | * @from: the user space buffer to read from |
| 612 | * @count: the maximum number of bytes to read |
| 613 | * |
| 614 | * The simple_write_to_buffer() function reads up to @count bytes from the user |
| 615 | * space address starting at @from into the buffer @to at offset @ppos. |
| 616 | * |
| 617 | * On success, the number of bytes written is returned and the offset @ppos is |
| 618 | * advanced by this number, or negative value is returned on error. |
| 619 | **/ |
| 620 | ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, |
| 621 | const void __user *from, size_t count) |
| 622 | { |
| 623 | loff_t pos = *ppos; |
| 624 | size_t res; |
| 625 | |
| 626 | if (pos < 0) |
| 627 | return -EINVAL; |
| 628 | if (pos >= available || !count) |
| 629 | return 0; |
| 630 | if (count > available - pos) |
| 631 | count = available - pos; |
| 632 | res = copy_from_user(to + pos, from, count); |
| 633 | if (res == count) |
| 634 | return -EFAULT; |
| 635 | count -= res; |
| 636 | *ppos = pos + count; |
| 637 | return count; |
| 638 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 639 | EXPORT_SYMBOL(simple_write_to_buffer); |
Jiri Slaby | 6a727b4 | 2010-05-01 23:51:22 +0200 | [diff] [blame] | 640 | |
| 641 | /** |
Akinobu Mita | 6d1029b | 2008-07-04 09:59:51 -0700 | [diff] [blame] | 642 | * memory_read_from_buffer - copy data from the buffer |
| 643 | * @to: the kernel space buffer to read to |
| 644 | * @count: the maximum number of bytes to read |
| 645 | * @ppos: the current position in the buffer |
| 646 | * @from: the buffer to read from |
| 647 | * @available: the size of the buffer |
| 648 | * |
| 649 | * The memory_read_from_buffer() function reads up to @count bytes from the |
| 650 | * buffer @from at offset @ppos into the kernel space address starting at @to. |
| 651 | * |
| 652 | * On success, the number of bytes read is returned and the offset @ppos is |
| 653 | * advanced by this number, or negative value is returned on error. |
| 654 | **/ |
Akinobu Mita | 93b0711 | 2008-06-05 22:46:21 -0700 | [diff] [blame] | 655 | ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, |
| 656 | const void *from, size_t available) |
| 657 | { |
| 658 | loff_t pos = *ppos; |
| 659 | |
| 660 | if (pos < 0) |
| 661 | return -EINVAL; |
| 662 | if (pos >= available) |
| 663 | return 0; |
| 664 | if (count > available - pos) |
| 665 | count = available - pos; |
| 666 | memcpy(to, from + pos, count); |
| 667 | *ppos = pos + count; |
| 668 | |
| 669 | return count; |
| 670 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 671 | EXPORT_SYMBOL(memory_read_from_buffer); |
Akinobu Mita | 93b0711 | 2008-06-05 22:46:21 -0700 | [diff] [blame] | 672 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | /* |
| 674 | * Transaction based IO. |
| 675 | * The file expects a single write which triggers the transaction, and then |
| 676 | * possibly a read which collects the result - which is stored in a |
| 677 | * file-local buffer. |
| 678 | */ |
Ingo Molnar | 76791ab | 2009-03-25 16:48:35 +0100 | [diff] [blame] | 679 | |
| 680 | void simple_transaction_set(struct file *file, size_t n) |
| 681 | { |
| 682 | struct simple_transaction_argresp *ar = file->private_data; |
| 683 | |
| 684 | BUG_ON(n > SIMPLE_TRANSACTION_LIMIT); |
| 685 | |
| 686 | /* |
| 687 | * The barrier ensures that ar->size will really remain zero until |
| 688 | * ar->data is ready for reading. |
| 689 | */ |
| 690 | smp_mb(); |
| 691 | ar->size = n; |
| 692 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 693 | EXPORT_SYMBOL(simple_transaction_set); |
Ingo Molnar | 76791ab | 2009-03-25 16:48:35 +0100 | [diff] [blame] | 694 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | char *simple_transaction_get(struct file *file, const char __user *buf, size_t size) |
| 696 | { |
| 697 | struct simple_transaction_argresp *ar; |
| 698 | static DEFINE_SPINLOCK(simple_transaction_lock); |
| 699 | |
| 700 | if (size > SIMPLE_TRANSACTION_LIMIT - 1) |
| 701 | return ERR_PTR(-EFBIG); |
| 702 | |
| 703 | ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL); |
| 704 | if (!ar) |
| 705 | return ERR_PTR(-ENOMEM); |
| 706 | |
| 707 | spin_lock(&simple_transaction_lock); |
| 708 | |
| 709 | /* only one write allowed per open */ |
| 710 | if (file->private_data) { |
| 711 | spin_unlock(&simple_transaction_lock); |
| 712 | free_page((unsigned long)ar); |
| 713 | return ERR_PTR(-EBUSY); |
| 714 | } |
| 715 | |
| 716 | file->private_data = ar; |
| 717 | |
| 718 | spin_unlock(&simple_transaction_lock); |
| 719 | |
| 720 | if (copy_from_user(ar->data, buf, size)) |
| 721 | return ERR_PTR(-EFAULT); |
| 722 | |
| 723 | return ar->data; |
| 724 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 725 | EXPORT_SYMBOL(simple_transaction_get); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | |
| 727 | ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos) |
| 728 | { |
| 729 | struct simple_transaction_argresp *ar = file->private_data; |
| 730 | |
| 731 | if (!ar) |
| 732 | return 0; |
| 733 | return simple_read_from_buffer(buf, size, pos, ar->data, ar->size); |
| 734 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 735 | EXPORT_SYMBOL(simple_transaction_read); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | |
| 737 | int simple_transaction_release(struct inode *inode, struct file *file) |
| 738 | { |
| 739 | free_page((unsigned long)file->private_data); |
| 740 | return 0; |
| 741 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 742 | EXPORT_SYMBOL(simple_transaction_release); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 744 | /* Simple attribute files */ |
| 745 | |
| 746 | struct simple_attr { |
Christoph Hellwig | 8b88b09 | 2008-02-08 04:20:26 -0800 | [diff] [blame] | 747 | int (*get)(void *, u64 *); |
| 748 | int (*set)(void *, u64); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 749 | char get_buf[24]; /* enough to store a u64 and "\n\0" */ |
| 750 | char set_buf[24]; |
| 751 | void *data; |
| 752 | const char *fmt; /* format for read operation */ |
Ingo Molnar | 7cf34c7 | 2006-03-23 03:00:36 -0800 | [diff] [blame] | 753 | struct mutex mutex; /* protects access to these buffers */ |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 754 | }; |
| 755 | |
| 756 | /* simple_attr_open is called by an actual attribute open file operation |
| 757 | * to set the attribute specific access operations. */ |
| 758 | int simple_attr_open(struct inode *inode, struct file *file, |
Christoph Hellwig | 8b88b09 | 2008-02-08 04:20:26 -0800 | [diff] [blame] | 759 | int (*get)(void *, u64 *), int (*set)(void *, u64), |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 760 | const char *fmt) |
| 761 | { |
| 762 | struct simple_attr *attr; |
| 763 | |
| 764 | attr = kmalloc(sizeof(*attr), GFP_KERNEL); |
| 765 | if (!attr) |
| 766 | return -ENOMEM; |
| 767 | |
| 768 | attr->get = get; |
| 769 | attr->set = set; |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 770 | attr->data = inode->i_private; |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 771 | attr->fmt = fmt; |
Ingo Molnar | 7cf34c7 | 2006-03-23 03:00:36 -0800 | [diff] [blame] | 772 | mutex_init(&attr->mutex); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 773 | |
| 774 | file->private_data = attr; |
| 775 | |
| 776 | return nonseekable_open(inode, file); |
| 777 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 778 | EXPORT_SYMBOL_GPL(simple_attr_open); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 779 | |
Christoph Hellwig | 74bedc4 | 2008-02-08 04:20:28 -0800 | [diff] [blame] | 780 | int simple_attr_release(struct inode *inode, struct file *file) |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 781 | { |
| 782 | kfree(file->private_data); |
| 783 | return 0; |
| 784 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 785 | EXPORT_SYMBOL_GPL(simple_attr_release); /* GPL-only? This? Really? */ |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 786 | |
| 787 | /* read from the buffer that is filled with the get function */ |
| 788 | ssize_t simple_attr_read(struct file *file, char __user *buf, |
| 789 | size_t len, loff_t *ppos) |
| 790 | { |
| 791 | struct simple_attr *attr; |
| 792 | size_t size; |
| 793 | ssize_t ret; |
| 794 | |
| 795 | attr = file->private_data; |
| 796 | |
| 797 | if (!attr->get) |
| 798 | return -EACCES; |
| 799 | |
Christoph Hellwig | 9261303 | 2008-02-08 04:20:27 -0800 | [diff] [blame] | 800 | ret = mutex_lock_interruptible(&attr->mutex); |
| 801 | if (ret) |
| 802 | return ret; |
| 803 | |
Christoph Hellwig | 8b88b09 | 2008-02-08 04:20:26 -0800 | [diff] [blame] | 804 | if (*ppos) { /* continued read */ |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 805 | size = strlen(attr->get_buf); |
Christoph Hellwig | 8b88b09 | 2008-02-08 04:20:26 -0800 | [diff] [blame] | 806 | } else { /* first read */ |
| 807 | u64 val; |
| 808 | ret = attr->get(attr->data, &val); |
| 809 | if (ret) |
| 810 | goto out; |
| 811 | |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 812 | size = scnprintf(attr->get_buf, sizeof(attr->get_buf), |
Christoph Hellwig | 8b88b09 | 2008-02-08 04:20:26 -0800 | [diff] [blame] | 813 | attr->fmt, (unsigned long long)val); |
| 814 | } |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 815 | |
| 816 | ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size); |
Christoph Hellwig | 8b88b09 | 2008-02-08 04:20:26 -0800 | [diff] [blame] | 817 | out: |
Ingo Molnar | 7cf34c7 | 2006-03-23 03:00:36 -0800 | [diff] [blame] | 818 | mutex_unlock(&attr->mutex); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 819 | return ret; |
| 820 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 821 | EXPORT_SYMBOL_GPL(simple_attr_read); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 822 | |
| 823 | /* interpret the buffer as a number to call the set function with */ |
| 824 | ssize_t simple_attr_write(struct file *file, const char __user *buf, |
| 825 | size_t len, loff_t *ppos) |
| 826 | { |
| 827 | struct simple_attr *attr; |
| 828 | u64 val; |
| 829 | size_t size; |
| 830 | ssize_t ret; |
| 831 | |
| 832 | attr = file->private_data; |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 833 | if (!attr->set) |
| 834 | return -EACCES; |
| 835 | |
Christoph Hellwig | 9261303 | 2008-02-08 04:20:27 -0800 | [diff] [blame] | 836 | ret = mutex_lock_interruptible(&attr->mutex); |
| 837 | if (ret) |
| 838 | return ret; |
| 839 | |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 840 | ret = -EFAULT; |
| 841 | size = min(sizeof(attr->set_buf) - 1, len); |
| 842 | if (copy_from_user(attr->set_buf, buf, size)) |
| 843 | goto out; |
| 844 | |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 845 | attr->set_buf[size] = '\0'; |
Akinobu Mita | f7b8863 | 2011-07-19 08:49:25 -0700 | [diff] [blame] | 846 | val = simple_strtoll(attr->set_buf, NULL, 0); |
Wu Fengguang | 05cc0ce | 2009-09-18 13:06:03 -0700 | [diff] [blame] | 847 | ret = attr->set(attr->data, val); |
| 848 | if (ret == 0) |
| 849 | ret = len; /* on success, claim we got the whole input */ |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 850 | out: |
Ingo Molnar | 7cf34c7 | 2006-03-23 03:00:36 -0800 | [diff] [blame] | 851 | mutex_unlock(&attr->mutex); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 852 | return ret; |
| 853 | } |
Al Viro | 12f3887 | 2013-09-15 21:20:49 -0400 | [diff] [blame] | 854 | EXPORT_SYMBOL_GPL(simple_attr_write); |
Arnd Bergmann | acaefc2 | 2005-05-18 14:40:59 +0200 | [diff] [blame] | 855 | |
Christoph Hellwig | 2596110 | 2007-10-21 16:42:05 -0700 | [diff] [blame] | 856 | /** |
| 857 | * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation |
| 858 | * @sb: filesystem to do the file handle conversion on |
| 859 | * @fid: file handle to convert |
| 860 | * @fh_len: length of the file handle in bytes |
| 861 | * @fh_type: type of file handle |
| 862 | * @get_inode: filesystem callback to retrieve inode |
| 863 | * |
| 864 | * This function decodes @fid as long as it has one of the well-known |
| 865 | * Linux filehandle types and calls @get_inode on it to retrieve the |
| 866 | * inode for the object specified in the file handle. |
| 867 | */ |
| 868 | struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid, |
| 869 | int fh_len, int fh_type, struct inode *(*get_inode) |
| 870 | (struct super_block *sb, u64 ino, u32 gen)) |
| 871 | { |
| 872 | struct inode *inode = NULL; |
| 873 | |
| 874 | if (fh_len < 2) |
| 875 | return NULL; |
| 876 | |
| 877 | switch (fh_type) { |
| 878 | case FILEID_INO32_GEN: |
| 879 | case FILEID_INO32_GEN_PARENT: |
| 880 | inode = get_inode(sb, fid->i32.ino, fid->i32.gen); |
| 881 | break; |
| 882 | } |
| 883 | |
Christoph Hellwig | 4ea3ada | 2008-08-11 15:48:57 +0200 | [diff] [blame] | 884 | return d_obtain_alias(inode); |
Christoph Hellwig | 2596110 | 2007-10-21 16:42:05 -0700 | [diff] [blame] | 885 | } |
| 886 | EXPORT_SYMBOL_GPL(generic_fh_to_dentry); |
| 887 | |
| 888 | /** |
Yanchuan Nian | ca18683 | 2012-09-05 16:31:29 +0800 | [diff] [blame] | 889 | * generic_fh_to_parent - generic helper for the fh_to_parent export operation |
Christoph Hellwig | 2596110 | 2007-10-21 16:42:05 -0700 | [diff] [blame] | 890 | * @sb: filesystem to do the file handle conversion on |
| 891 | * @fid: file handle to convert |
| 892 | * @fh_len: length of the file handle in bytes |
| 893 | * @fh_type: type of file handle |
| 894 | * @get_inode: filesystem callback to retrieve inode |
| 895 | * |
| 896 | * This function decodes @fid as long as it has one of the well-known |
| 897 | * Linux filehandle types and calls @get_inode on it to retrieve the |
| 898 | * inode for the _parent_ object specified in the file handle if it |
| 899 | * is specified in the file handle, or NULL otherwise. |
| 900 | */ |
| 901 | struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid, |
| 902 | int fh_len, int fh_type, struct inode *(*get_inode) |
| 903 | (struct super_block *sb, u64 ino, u32 gen)) |
| 904 | { |
| 905 | struct inode *inode = NULL; |
| 906 | |
| 907 | if (fh_len <= 2) |
| 908 | return NULL; |
| 909 | |
| 910 | switch (fh_type) { |
| 911 | case FILEID_INO32_GEN_PARENT: |
| 912 | inode = get_inode(sb, fid->i32.parent_ino, |
| 913 | (fh_len > 3 ? fid->i32.parent_gen : 0)); |
| 914 | break; |
| 915 | } |
| 916 | |
Christoph Hellwig | 4ea3ada | 2008-08-11 15:48:57 +0200 | [diff] [blame] | 917 | return d_obtain_alias(inode); |
Christoph Hellwig | 2596110 | 2007-10-21 16:42:05 -0700 | [diff] [blame] | 918 | } |
| 919 | EXPORT_SYMBOL_GPL(generic_fh_to_parent); |
| 920 | |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 921 | /** |
Fabian Frederick | ac13a82 | 2014-06-04 16:06:27 -0700 | [diff] [blame] | 922 | * __generic_file_fsync - generic fsync implementation for simple filesystems |
| 923 | * |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 924 | * @file: file to synchronize |
Fabian Frederick | ac13a82 | 2014-06-04 16:06:27 -0700 | [diff] [blame] | 925 | * @start: start offset in bytes |
| 926 | * @end: end offset in bytes (inclusive) |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 927 | * @datasync: only synchronize essential metadata if true |
| 928 | * |
| 929 | * This is a generic implementation of the fsync method for simple |
| 930 | * filesystems which track all non-inode metadata in the buffers list |
| 931 | * hanging off the address_space structure. |
| 932 | */ |
Fabian Frederick | ac13a82 | 2014-06-04 16:06:27 -0700 | [diff] [blame] | 933 | int __generic_file_fsync(struct file *file, loff_t start, loff_t end, |
| 934 | int datasync) |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 935 | { |
Christoph Hellwig | 7ea8085 | 2010-05-26 17:53:25 +0200 | [diff] [blame] | 936 | struct inode *inode = file->f_mapping->host; |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 937 | int err; |
| 938 | int ret; |
| 939 | |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 940 | err = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| 941 | if (err) |
| 942 | return err; |
| 943 | |
| 944 | mutex_lock(&inode->i_mutex); |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 945 | ret = sync_mapping_buffers(inode->i_mapping); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 946 | if (!(inode->i_state & I_DIRTY_ALL)) |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 947 | goto out; |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 948 | if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 949 | goto out; |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 950 | |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 951 | err = sync_inode_metadata(inode, 1); |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 952 | if (ret == 0) |
| 953 | ret = err; |
Fabian Frederick | ac13a82 | 2014-06-04 16:06:27 -0700 | [diff] [blame] | 954 | |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 955 | out: |
| 956 | mutex_unlock(&inode->i_mutex); |
Al Viro | d5aacad | 2009-06-07 14:56:44 -0400 | [diff] [blame] | 957 | return ret; |
| 958 | } |
Fabian Frederick | ac13a82 | 2014-06-04 16:06:27 -0700 | [diff] [blame] | 959 | EXPORT_SYMBOL(__generic_file_fsync); |
| 960 | |
| 961 | /** |
| 962 | * generic_file_fsync - generic fsync implementation for simple filesystems |
| 963 | * with flush |
| 964 | * @file: file to synchronize |
| 965 | * @start: start offset in bytes |
| 966 | * @end: end offset in bytes (inclusive) |
| 967 | * @datasync: only synchronize essential metadata if true |
| 968 | * |
| 969 | */ |
| 970 | |
| 971 | int generic_file_fsync(struct file *file, loff_t start, loff_t end, |
| 972 | int datasync) |
| 973 | { |
| 974 | struct inode *inode = file->f_mapping->host; |
| 975 | int err; |
| 976 | |
| 977 | err = __generic_file_fsync(file, start, end, datasync); |
| 978 | if (err) |
| 979 | return err; |
| 980 | return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); |
| 981 | } |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 982 | EXPORT_SYMBOL(generic_file_fsync); |
| 983 | |
Patrick J. LoPresti | 30ca22c | 2010-07-22 15:03:41 -0700 | [diff] [blame] | 984 | /** |
| 985 | * generic_check_addressable - Check addressability of file system |
| 986 | * @blocksize_bits: log of file system block size |
| 987 | * @num_blocks: number of blocks in file system |
| 988 | * |
| 989 | * Determine whether a file system with @num_blocks blocks (and a |
| 990 | * block size of 2**@blocksize_bits) is addressable by the sector_t |
| 991 | * and page cache of the system. Return 0 if so and -EFBIG otherwise. |
| 992 | */ |
| 993 | int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks) |
| 994 | { |
| 995 | u64 last_fs_block = num_blocks - 1; |
Joel Becker | a33f13e | 2010-08-16 12:10:17 -0700 | [diff] [blame] | 996 | u64 last_fs_page = |
| 997 | last_fs_block >> (PAGE_CACHE_SHIFT - blocksize_bits); |
Patrick J. LoPresti | 30ca22c | 2010-07-22 15:03:41 -0700 | [diff] [blame] | 998 | |
| 999 | if (unlikely(num_blocks == 0)) |
| 1000 | return 0; |
| 1001 | |
| 1002 | if ((blocksize_bits < 9) || (blocksize_bits > PAGE_CACHE_SHIFT)) |
| 1003 | return -EINVAL; |
| 1004 | |
Joel Becker | a33f13e | 2010-08-16 12:10:17 -0700 | [diff] [blame] | 1005 | if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) || |
| 1006 | (last_fs_page > (pgoff_t)(~0ULL))) { |
Patrick J. LoPresti | 30ca22c | 2010-07-22 15:03:41 -0700 | [diff] [blame] | 1007 | return -EFBIG; |
| 1008 | } |
| 1009 | return 0; |
| 1010 | } |
| 1011 | EXPORT_SYMBOL(generic_check_addressable); |
| 1012 | |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 1013 | /* |
| 1014 | * No-op implementation of ->fsync for in-memory filesystems. |
| 1015 | */ |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 1016 | int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 1017 | { |
| 1018 | return 0; |
| 1019 | } |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 1020 | EXPORT_SYMBOL(noop_fsync); |
Al Viro | 87dc800 | 2013-09-16 10:30:04 -0400 | [diff] [blame] | 1021 | |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 1022 | /* Because kfree isn't assignment-compatible with void(void*) ;-/ */ |
| 1023 | void kfree_link(void *p) |
Al Viro | 87dc800 | 2013-09-16 10:30:04 -0400 | [diff] [blame] | 1024 | { |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 1025 | kfree(p); |
Al Viro | 87dc800 | 2013-09-16 10:30:04 -0400 | [diff] [blame] | 1026 | } |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 1027 | EXPORT_SYMBOL(kfree_link); |
Al Viro | 6987843 | 2013-10-02 22:35:11 -0400 | [diff] [blame] | 1028 | |
| 1029 | /* |
| 1030 | * nop .set_page_dirty method so that people can use .page_mkwrite on |
| 1031 | * anon inodes. |
| 1032 | */ |
| 1033 | static int anon_set_page_dirty(struct page *page) |
| 1034 | { |
| 1035 | return 0; |
| 1036 | }; |
| 1037 | |
| 1038 | /* |
| 1039 | * A single inode exists for all anon_inode files. Contrary to pipes, |
| 1040 | * anon_inode inodes have no associated per-instance data, so we need |
| 1041 | * only allocate one of them. |
| 1042 | */ |
| 1043 | struct inode *alloc_anon_inode(struct super_block *s) |
| 1044 | { |
| 1045 | static const struct address_space_operations anon_aops = { |
| 1046 | .set_page_dirty = anon_set_page_dirty, |
| 1047 | }; |
| 1048 | struct inode *inode = new_inode_pseudo(s); |
| 1049 | |
| 1050 | if (!inode) |
| 1051 | return ERR_PTR(-ENOMEM); |
| 1052 | |
| 1053 | inode->i_ino = get_next_ino(); |
| 1054 | inode->i_mapping->a_ops = &anon_aops; |
| 1055 | |
| 1056 | /* |
| 1057 | * Mark the inode dirty from the very beginning, |
| 1058 | * that way it will never be moved to the dirty |
| 1059 | * list because mark_inode_dirty() will think |
| 1060 | * that it already _is_ on the dirty list. |
| 1061 | */ |
| 1062 | inode->i_state = I_DIRTY; |
| 1063 | inode->i_mode = S_IRUSR | S_IWUSR; |
| 1064 | inode->i_uid = current_fsuid(); |
| 1065 | inode->i_gid = current_fsgid(); |
| 1066 | inode->i_flags |= S_PRIVATE; |
| 1067 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 1068 | return inode; |
| 1069 | } |
| 1070 | EXPORT_SYMBOL(alloc_anon_inode); |
Jeff Layton | 1c994a0 | 2014-08-27 06:49:41 -0400 | [diff] [blame] | 1071 | |
| 1072 | /** |
| 1073 | * simple_nosetlease - generic helper for prohibiting leases |
| 1074 | * @filp: file pointer |
| 1075 | * @arg: type of lease to obtain |
| 1076 | * @flp: new lease supplied for insertion |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1077 | * @priv: private data for lm_setup operation |
Jeff Layton | 1c994a0 | 2014-08-27 06:49:41 -0400 | [diff] [blame] | 1078 | * |
| 1079 | * Generic helper for filesystems that do not wish to allow leases to be set. |
| 1080 | * All arguments are ignored and it just returns -EINVAL. |
| 1081 | */ |
| 1082 | int |
Jeff Layton | e6f5c78 | 2014-08-22 10:40:25 -0400 | [diff] [blame] | 1083 | simple_nosetlease(struct file *filp, long arg, struct file_lock **flp, |
| 1084 | void **priv) |
Jeff Layton | 1c994a0 | 2014-08-27 06:49:41 -0400 | [diff] [blame] | 1085 | { |
| 1086 | return -EINVAL; |
| 1087 | } |
| 1088 | EXPORT_SYMBOL(simple_nosetlease); |
Al Viro | 61ba64f | 2015-05-02 09:54:06 -0400 | [diff] [blame] | 1089 | |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 1090 | const char *simple_get_link(struct dentry *dentry, struct inode *inode, |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 1091 | struct delayed_call *done) |
Al Viro | 61ba64f | 2015-05-02 09:54:06 -0400 | [diff] [blame] | 1092 | { |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 1093 | return inode->i_link; |
Al Viro | 61ba64f | 2015-05-02 09:54:06 -0400 | [diff] [blame] | 1094 | } |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 1095 | EXPORT_SYMBOL(simple_get_link); |
Al Viro | 61ba64f | 2015-05-02 09:54:06 -0400 | [diff] [blame] | 1096 | |
| 1097 | const struct inode_operations simple_symlink_inode_operations = { |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 1098 | .get_link = simple_get_link, |
Al Viro | 61ba64f | 2015-05-02 09:54:06 -0400 | [diff] [blame] | 1099 | .readlink = generic_readlink |
| 1100 | }; |
| 1101 | EXPORT_SYMBOL(simple_symlink_inode_operations); |
Eric W. Biederman | fbabfd0 | 2015-05-09 15:54:49 -0500 | [diff] [blame] | 1102 | |
| 1103 | /* |
| 1104 | * Operations for a permanently empty directory. |
| 1105 | */ |
| 1106 | static struct dentry *empty_dir_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
| 1107 | { |
| 1108 | return ERR_PTR(-ENOENT); |
| 1109 | } |
| 1110 | |
| 1111 | static int empty_dir_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| 1112 | struct kstat *stat) |
| 1113 | { |
| 1114 | struct inode *inode = d_inode(dentry); |
| 1115 | generic_fillattr(inode, stat); |
| 1116 | return 0; |
| 1117 | } |
| 1118 | |
| 1119 | static int empty_dir_setattr(struct dentry *dentry, struct iattr *attr) |
| 1120 | { |
| 1121 | return -EPERM; |
| 1122 | } |
| 1123 | |
| 1124 | static int empty_dir_setxattr(struct dentry *dentry, const char *name, |
| 1125 | const void *value, size_t size, int flags) |
| 1126 | { |
| 1127 | return -EOPNOTSUPP; |
| 1128 | } |
| 1129 | |
| 1130 | static ssize_t empty_dir_getxattr(struct dentry *dentry, const char *name, |
| 1131 | void *value, size_t size) |
| 1132 | { |
| 1133 | return -EOPNOTSUPP; |
| 1134 | } |
| 1135 | |
| 1136 | static int empty_dir_removexattr(struct dentry *dentry, const char *name) |
| 1137 | { |
| 1138 | return -EOPNOTSUPP; |
| 1139 | } |
| 1140 | |
| 1141 | static ssize_t empty_dir_listxattr(struct dentry *dentry, char *list, size_t size) |
| 1142 | { |
| 1143 | return -EOPNOTSUPP; |
| 1144 | } |
| 1145 | |
| 1146 | static const struct inode_operations empty_dir_inode_operations = { |
| 1147 | .lookup = empty_dir_lookup, |
| 1148 | .permission = generic_permission, |
| 1149 | .setattr = empty_dir_setattr, |
| 1150 | .getattr = empty_dir_getattr, |
| 1151 | .setxattr = empty_dir_setxattr, |
| 1152 | .getxattr = empty_dir_getxattr, |
| 1153 | .removexattr = empty_dir_removexattr, |
| 1154 | .listxattr = empty_dir_listxattr, |
| 1155 | }; |
| 1156 | |
| 1157 | static loff_t empty_dir_llseek(struct file *file, loff_t offset, int whence) |
| 1158 | { |
| 1159 | /* An empty directory has two entries . and .. at offsets 0 and 1 */ |
| 1160 | return generic_file_llseek_size(file, offset, whence, 2, 2); |
| 1161 | } |
| 1162 | |
| 1163 | static int empty_dir_readdir(struct file *file, struct dir_context *ctx) |
| 1164 | { |
| 1165 | dir_emit_dots(file, ctx); |
| 1166 | return 0; |
| 1167 | } |
| 1168 | |
| 1169 | static const struct file_operations empty_dir_operations = { |
| 1170 | .llseek = empty_dir_llseek, |
| 1171 | .read = generic_read_dir, |
| 1172 | .iterate = empty_dir_readdir, |
| 1173 | .fsync = noop_fsync, |
| 1174 | }; |
| 1175 | |
| 1176 | |
| 1177 | void make_empty_dir_inode(struct inode *inode) |
| 1178 | { |
| 1179 | set_nlink(inode, 2); |
| 1180 | inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; |
| 1181 | inode->i_uid = GLOBAL_ROOT_UID; |
| 1182 | inode->i_gid = GLOBAL_ROOT_GID; |
| 1183 | inode->i_rdev = 0; |
Eric W. Biederman | 4b75de86 | 2015-08-12 15:00:12 -0500 | [diff] [blame] | 1184 | inode->i_size = 0; |
Eric W. Biederman | fbabfd0 | 2015-05-09 15:54:49 -0500 | [diff] [blame] | 1185 | inode->i_blkbits = PAGE_SHIFT; |
| 1186 | inode->i_blocks = 0; |
| 1187 | |
| 1188 | inode->i_op = &empty_dir_inode_operations; |
| 1189 | inode->i_fop = &empty_dir_operations; |
| 1190 | } |
| 1191 | |
| 1192 | bool is_empty_dir_inode(struct inode *inode) |
| 1193 | { |
| 1194 | return (inode->i_fop == &empty_dir_operations) && |
| 1195 | (inode->i_op == &empty_dir_inode_operations); |
| 1196 | } |