module/zfs/zpl_super.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2011, Lawrence Livermore National Security, LLC.
  23  */
  24
  25
  26 #include <sys/zfs_vfsops.h>
  27 #include <sys/zfs_vnops.h>
  28 #include <sys/zfs_znode.h>
  29 #include <sys/zfs_ctldir.h>
  30 #include <sys/zpl.h>
  31
  32
  33 static struct inode *
  34 zpl_inode_alloc(struct super_block *sb)
  35 {
  36         struct inode *ip;
  37
  38         VERIFY3S(zfs_inode_alloc(sb, &ip), ==, 0);
  39         ip->i_version = 1;
  40
  41         return (ip);
  42 }
  43
  44 static void
  45 zpl_inode_destroy(struct inode *ip)
  46 {
  47         ASSERT(atomic_read(&ip->i_count) == 0);
  48         zfs_inode_destroy(ip);
  49 }
  50
  51 /*
  52  * Called from __mark_inode_dirty() to reflect that something in the
  53  * inode has changed.  We use it to ensure the znode system attributes
  54  * are always strictly update to date with respect to the inode.
  55  */
  56 #ifdef HAVE_DIRTY_INODE_WITH_FLAGS
  57 static void
  58 zpl_dirty_inode(struct inode *ip, int flags)
  59 {
  60         fstrans_cookie_t cookie;
  61
  62         cookie = spl_fstrans_mark();
  63         zfs_dirty_inode(ip, flags);
  64         spl_fstrans_unmark(cookie);
  65 }
  66 #else
  67 static void
  68 zpl_dirty_inode(struct inode *ip)
  69 {
  70         fstrans_cookie_t cookie;
  71
  72         cookie = spl_fstrans_mark();
  73         zfs_dirty_inode(ip, 0);
  74         spl_fstrans_unmark(cookie);
  75 }
  76 #endif /* HAVE_DIRTY_INODE_WITH_FLAGS */
  77
  78 /*
  79  * When ->drop_inode() is called its return value indicates if the
  80  * inode should be evicted from the inode cache.  If the inode is
  81  * unhashed and has no links the default policy is to evict it
  82  * immediately.
  83  *
  84  * Prior to 2.6.36 this eviction was accomplished by the vfs calling
  85  * ->delete_inode().  It was ->delete_inode()'s responsibility to
  86  * truncate the inode pages and call clear_inode().  The call to
  87  * clear_inode() synchronously invalidates all the buffers and
  88  * calls ->clear_inode().  It was ->clear_inode()'s responsibility
  89  * to cleanup and filesystem specific data before freeing the inode.
  90  *
  91  * This elaborate mechanism was replaced by ->evict_inode() which
  92  * does the job of both ->delete_inode() and ->clear_inode().  It
  93  * will be called exactly once, and when it returns the inode must
  94  * be in a state where it can simply be freed.i
  95  *
  96  * The ->evict_inode() callback must minimally truncate the inode pages,
  97  * and call clear_inode().  For 2.6.35 and later kernels this will
  98  * simply update the inode state, with the sync occurring before the
  99  * truncate in evict().  For earlier kernels clear_inode() maps to
 100  * end_writeback() which is responsible for completing all outstanding
 101  * write back.  In either case, once this is done it is safe to cleanup
 102  * any remaining inode specific data via zfs_inactive().
 103  * remaining filesystem specific data.
 104  */
 105 #ifdef HAVE_EVICT_INODE
 106 static void
 107 zpl_evict_inode(struct inode *ip)
 108 {
 109         fstrans_cookie_t cookie;
 110
 111         cookie = spl_fstrans_mark();
 112         truncate_setsize(ip, 0);
 113         clear_inode(ip);
 114         zfs_inactive(ip);
 115         spl_fstrans_unmark(cookie);
 116 }
 117
 118 #else
 119
 120 static void
 121 zpl_drop_inode(struct inode *ip)
 122 {
 123         generic_delete_inode(ip);
 124 }
 125
 126 static void
 127 zpl_clear_inode(struct inode *ip)
 128 {
 129         fstrans_cookie_t cookie;
 130
 131         cookie = spl_fstrans_mark();
 132         zfs_inactive(ip);
 133         spl_fstrans_unmark(cookie);
 134 }
 135
 136 static void
 137 zpl_inode_delete(struct inode *ip)
 138 {
 139         truncate_setsize(ip, 0);
 140         clear_inode(ip);
 141 }
 142 #endif /* HAVE_EVICT_INODE */
 143
 144 static void
 145 zpl_put_super(struct super_block *sb)
 146 {
 147         fstrans_cookie_t cookie;
 148         int error;
 149
 150         cookie = spl_fstrans_mark();
 151         error = -zfs_umount(sb);
 152         spl_fstrans_unmark(cookie);
 153         ASSERT3S(error, <=, 0);
 154 }
 155
 156 static int
 157 zpl_sync_fs(struct super_block *sb, int wait)
 158 {
 159         fstrans_cookie_t cookie;
 160         cred_t *cr = CRED();
 161         int error;
 162
 163         crhold(cr);
 164         cookie = spl_fstrans_mark();
 165         error = -zfs_sync(sb, wait, cr);
 166         spl_fstrans_unmark(cookie);
 167         crfree(cr);
 168         ASSERT3S(error, <=, 0);
 169
 170         return (error);
 171 }
 172
 173 static int
 174 zpl_statfs(struct dentry *dentry, struct kstatfs *statp)
 175 {
 176         fstrans_cookie_t cookie;
 177         int error;
 178
 179         cookie = spl_fstrans_mark();
 180         error = -zfs_statvfs(dentry, statp);
 181         spl_fstrans_unmark(cookie);
 182         ASSERT3S(error, <=, 0);
 183
 184         return (error);
 185 }
 186
 187 static int
 188 zpl_remount_fs(struct super_block *sb, int *flags, char *data)
 189 {
 190         zfs_mnt_t zm = { .mnt_osname = NULL, .mnt_data = data };
 191         fstrans_cookie_t cookie;
 192         int error;
 193
 194         cookie = spl_fstrans_mark();
 195         error = -zfs_remount(sb, flags, &zm);
 196         spl_fstrans_unmark(cookie);
 197         ASSERT3S(error, <=, 0);
 198
 199         return (error);
 200 }
 201
 202 static int
 203 __zpl_show_options(struct seq_file *seq, zfsvfs_t *zfsvfs)
 204 {
 205         seq_printf(seq, ",%s",
 206             zfsvfs->z_flags & ZSB_XATTR ? "xattr" : "noxattr");
 207
 208 #ifdef CONFIG_FS_POSIX_ACL
 209         switch (zfsvfs->z_acl_type) {
 210         case ZFS_ACLTYPE_POSIXACL:
 211                 seq_puts(seq, ",posixacl");
 212                 break;
 213         default:
 214                 seq_puts(seq, ",noacl");
 215                 break;
 216         }
 217 #endif /* CONFIG_FS_POSIX_ACL */
 218
 219         return (0);
 220 }
 221
 222 #ifdef HAVE_SHOW_OPTIONS_WITH_DENTRY
 223 static int
 224 zpl_show_options(struct seq_file *seq, struct dentry *root)
 225 {
 226         return (__zpl_show_options(seq, root->d_sb->s_fs_info));
 227 }
 228 #else
 229 static int
 230 zpl_show_options(struct seq_file *seq, struct vfsmount *vfsp)
 231 {
 232         return (__zpl_show_options(seq, vfsp->mnt_sb->s_fs_info));
 233 }
 234 #endif /* HAVE_SHOW_OPTIONS_WITH_DENTRY */
 235
 236 static int
 237 zpl_fill_super(struct super_block *sb, void *data, int silent)
 238 {
 239         zfs_mnt_t *zm = (zfs_mnt_t *)data;
 240         fstrans_cookie_t cookie;
 241         int error;
 242
 243         cookie = spl_fstrans_mark();
 244         error = -zfs_domount(sb, zm, silent);
 245         spl_fstrans_unmark(cookie);
 246         ASSERT3S(error, <=, 0);
 247
 248         return (error);
 249 }
 250
 251 #ifdef HAVE_MOUNT_NODEV
 252 static struct dentry *
 253 zpl_mount(struct file_system_type *fs_type, int flags,
 254     const char *osname, void *data)
 255 {
 256         zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };
 257
 258         return (mount_nodev(fs_type, flags, &zm, zpl_fill_super));
 259 }
 260 #else
 261 static int
 262 zpl_get_sb(struct file_system_type *fs_type, int flags,
 263     const char *osname, void *data, struct vfsmount *mnt)
 264 {
 265         zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };
 266
 267         return (get_sb_nodev(fs_type, flags, &zm, zpl_fill_super, mnt));
 268 }
 269 #endif /* HAVE_MOUNT_NODEV */
 270
 271 static void
 272 zpl_kill_sb(struct super_block *sb)
 273 {
 274         zfs_preumount(sb);
 275         kill_anon_super(sb);
 276
 277 #ifdef HAVE_S_INSTANCES_LIST_HEAD
 278         sb->s_instances.next = &(zpl_fs_type.fs_supers);
 279 #endif /* HAVE_S_INSTANCES_LIST_HEAD */
 280 }
 281
 282 void
 283 zpl_prune_sb(int64_t nr_to_scan, void *arg)
 284 {
 285         struct super_block *sb = (struct super_block *)arg;
 286         int objects = 0;
 287
 288         (void) -zfs_prune(sb, nr_to_scan, &objects);
 289 }
 290
 291 #ifdef HAVE_NR_CACHED_OBJECTS
 292 static int
 293 zpl_nr_cached_objects(struct super_block *sb)
 294 {
 295         return (0);
 296 }
 297 #endif /* HAVE_NR_CACHED_OBJECTS */
 298
 299 #ifdef HAVE_FREE_CACHED_OBJECTS
 300 static void
 301 zpl_free_cached_objects(struct super_block *sb, int nr_to_scan)
 302 {
 303         /* noop */
 304 }
 305 #endif /* HAVE_FREE_CACHED_OBJECTS */
 306
 307 const struct super_operations zpl_super_operations = {
 308         .alloc_inode            = zpl_inode_alloc,
 309         .destroy_inode          = zpl_inode_destroy,
 310         .dirty_inode            = zpl_dirty_inode,
 311         .write_inode            = NULL,
 312 #ifdef HAVE_EVICT_INODE
 313         .evict_inode            = zpl_evict_inode,
 314 #else
 315         .drop_inode             = zpl_drop_inode,
 316         .clear_inode            = zpl_clear_inode,
 317         .delete_inode           = zpl_inode_delete,
 318 #endif /* HAVE_EVICT_INODE */
 319         .put_super              = zpl_put_super,
 320         .sync_fs                = zpl_sync_fs,
 321         .statfs                 = zpl_statfs,
 322         .remount_fs             = zpl_remount_fs,
 323         .show_options           = zpl_show_options,
 324         .show_stats             = NULL,
 325 #ifdef HAVE_NR_CACHED_OBJECTS
 326         .nr_cached_objects      = zpl_nr_cached_objects,
 327 #endif /* HAVE_NR_CACHED_OBJECTS */
 328 #ifdef HAVE_FREE_CACHED_OBJECTS
 329         .free_cached_objects    = zpl_free_cached_objects,
 330 #endif /* HAVE_FREE_CACHED_OBJECTS */
 331 };
 332
 333 struct file_system_type zpl_fs_type = {
 334         .owner                  = THIS_MODULE,
 335         .name                   = ZFS_DRIVER,
 336 #ifdef HAVE_MOUNT_NODEV
 337         .mount                  = zpl_mount,
 338 #else
 339         .get_sb                 = zpl_get_sb,
 340 #endif /* HAVE_MOUNT_NODEV */
 341         .kill_sb                = zpl_kill_sb,
 342 };