1 files changed, 326 insertions, 0 deletions
diff --git a/module/os/linux/zfs/zpl_super.c b/module/os/linux/zfs/zpl_super.c
new file mode 100644
index 0000000000000..75adff51782ec
--- /dev/null
+++ b/module/os/linux/zfs/zpl_super.c
@@ -0,0 +1,326 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2011, Lawrence Livermore National Security, LLC.
+ */
+
+
+#include <sys/zfs_znode.h>
+#include <sys/zfs_vfsops.h>
+#include <sys/zfs_vnops.h>
+#include <sys/zfs_ctldir.h>
+#include <sys/zpl.h>
+
+
+static struct inode *
+zpl_inode_alloc(struct super_block *sb)
+{
+	struct inode *ip;
+
+	VERIFY3S(zfs_inode_alloc(sb, &ip), ==, 0);
+	inode_set_iversion(ip, 1);
+
+	return (ip);
+}
+
+static void
+zpl_inode_destroy(struct inode *ip)
+{
+	ASSERT(atomic_read(&ip->i_count) == 0);
+	zfs_inode_destroy(ip);
+}
+
+/*
+ * Called from __mark_inode_dirty() to reflect that something in the
+ * inode has changed.  We use it to ensure the znode system attributes
+ * are always strictly update to date with respect to the inode.
+ */
+#ifdef HAVE_DIRTY_INODE_WITH_FLAGS
+static void
+zpl_dirty_inode(struct inode *ip, int flags)
+{
+	fstrans_cookie_t cookie;
+
+	cookie = spl_fstrans_mark();
+	zfs_dirty_inode(ip, flags);
+	spl_fstrans_unmark(cookie);
+}
+#else
+static void
+zpl_dirty_inode(struct inode *ip)
+{
+	fstrans_cookie_t cookie;
+
+	cookie = spl_fstrans_mark();
+	zfs_dirty_inode(ip, 0);
+	spl_fstrans_unmark(cookie);
+}
+#endif /* HAVE_DIRTY_INODE_WITH_FLAGS */
+
+/*
+ * When ->drop_inode() is called its return value indicates if the
+ * inode should be evicted from the inode cache.  If the inode is
+ * unhashed and has no links the default policy is to evict it
+ * immediately.
+ *
+ * The ->evict_inode() callback must minimally truncate the inode pages,
+ * and call clear_inode().  For 2.6.35 and later kernels this will
+ * simply update the inode state, with the sync occurring before the
+ * truncate in evict().  For earlier kernels clear_inode() maps to
+ * end_writeback() which is responsible for completing all outstanding
+ * write back.  In either case, once this is done it is safe to cleanup
+ * any remaining inode specific data via zfs_inactive().
+ * remaining filesystem specific data.
+ */
+static void
+zpl_evict_inode(struct inode *ip)
+{
+	fstrans_cookie_t cookie;
+
+	cookie = spl_fstrans_mark();
+	truncate_setsize(ip, 0);
+	clear_inode(ip);
+	zfs_inactive(ip);
+	spl_fstrans_unmark(cookie);
+}
+
+static void
+zpl_put_super(struct super_block *sb)
+{
+	fstrans_cookie_t cookie;
+	int error;
+
+	cookie = spl_fstrans_mark();
+	error = -zfs_umount(sb);
+	spl_fstrans_unmark(cookie);
+	ASSERT3S(error, <=, 0);
+}
+
+static int
+zpl_sync_fs(struct super_block *sb, int wait)
+{
+	fstrans_cookie_t cookie;
+	cred_t *cr = CRED();
+	int error;
+
+	crhold(cr);
+	cookie = spl_fstrans_mark();
+	error = -zfs_sync(sb, wait, cr);
+	spl_fstrans_unmark(cookie);
+	crfree(cr);
+	ASSERT3S(error, <=, 0);
+
+	return (error);
+}
+
+static int
+zpl_statfs(struct dentry *dentry, struct kstatfs *statp)
+{
+	fstrans_cookie_t cookie;
+	int error;
+
+	cookie = spl_fstrans_mark();
+	error = -zfs_statvfs(dentry->d_inode, statp);
+	spl_fstrans_unmark(cookie);
+	ASSERT3S(error, <=, 0);
+
+	/*
+	 * If required by a 32-bit system call, dynamically scale the
+	 * block size up to 16MiB and decrease the block counts.  This
+	 * allows for a maximum size of 64EiB to be reported.  The file
+	 * counts must be artificially capped at 2^32-1.
+	 */
+	if (unlikely(zpl_is_32bit_api())) {
+		while (statp->f_blocks > UINT32_MAX &&
+		    statp->f_bsize < SPA_MAXBLOCKSIZE) {
+			statp->f_frsize <<= 1;
+			statp->f_bsize <<= 1;
+
+			statp->f_blocks >>= 1;
+			statp->f_bfree >>= 1;
+			statp->f_bavail >>= 1;
+		}
+
+		uint64_t usedobjs = statp->f_files - statp->f_ffree;
+		statp->f_ffree = MIN(statp->f_ffree, UINT32_MAX - usedobjs);
+		statp->f_files = statp->f_ffree + usedobjs;
+	}
+
+	return (error);
+}
+
+static int
+zpl_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+	zfs_mnt_t zm = { .mnt_osname = NULL, .mnt_data = data };
+	fstrans_cookie_t cookie;
+	int error;
+
+	cookie = spl_fstrans_mark();
+	error = -zfs_remount(sb, flags, &zm);
+	spl_fstrans_unmark(cookie);
+	ASSERT3S(error, <=, 0);
+
+	return (error);
+}
+
+static int
+__zpl_show_options(struct seq_file *seq, zfsvfs_t *zfsvfs)
+{
+	seq_printf(seq, ",%s",
+	    zfsvfs->z_flags & ZSB_XATTR ? "xattr" : "noxattr");
+
+#ifdef CONFIG_FS_POSIX_ACL
+	switch (zfsvfs->z_acl_type) {
+	case ZFS_ACLTYPE_POSIXACL:
+		seq_puts(seq, ",posixacl");
+		break;
+	default:
+		seq_puts(seq, ",noacl");
+		break;
+	}
+#endif /* CONFIG_FS_POSIX_ACL */
+
+	return (0);
+}
+
+static int
+zpl_show_options(struct seq_file *seq, struct dentry *root)
+{
+	return (__zpl_show_options(seq, root->d_sb->s_fs_info));
+}
+
+static int
+zpl_fill_super(struct super_block *sb, void *data, int silent)
+{
+	zfs_mnt_t *zm = (zfs_mnt_t *)data;
+	fstrans_cookie_t cookie;
+	int error;
+
+	cookie = spl_fstrans_mark();
+	error = -zfs_domount(sb, zm, silent);
+	spl_fstrans_unmark(cookie);
+	ASSERT3S(error, <=, 0);
+
+	return (error);
+}
+
+static int
+zpl_test_super(struct super_block *s, void *data)
+{
+	zfsvfs_t *zfsvfs = s->s_fs_info;
+	objset_t *os = data;
+
+	if (zfsvfs == NULL)
+		return (0);
+
+	return (os == zfsvfs->z_os);
+}
+
+static struct super_block *
+zpl_mount_impl(struct file_system_type *fs_type, int flags, zfs_mnt_t *zm)
+{
+	struct super_block *s;
+	objset_t *os;
+	int err;
+
+	err = dmu_objset_hold(zm->mnt_osname, FTAG, &os);
+	if (err)
+		return (ERR_PTR(-err));
+
+	/*
+	 * The dsl pool lock must be released prior to calling sget().
+	 * It is possible sget() may block on the lock in grab_super()
+	 * while deactivate_super() holds that same lock and waits for
+	 * a txg sync.  If the dsl_pool lock is held over sget()
+	 * this can prevent the pool sync and cause a deadlock.
+	 */
+	dsl_pool_rele(dmu_objset_pool(os), FTAG);
+	s = sget(fs_type, zpl_test_super, set_anon_super, flags, os);
+	dsl_dataset_rele(dmu_objset_ds(os), FTAG);
+
+	if (IS_ERR(s))
+		return (ERR_CAST(s));
+
+	if (s->s_root == NULL) {
+		err = zpl_fill_super(s, zm, flags & SB_SILENT ? 1 : 0);
+		if (err) {
+			deactivate_locked_super(s);
+			return (ERR_PTR(err));
+		}
+		s->s_flags |= SB_ACTIVE;
+	} else if ((flags ^ s->s_flags) & SB_RDONLY) {
+		deactivate_locked_super(s);
+		return (ERR_PTR(-EBUSY));
+	}
+
+	return (s);
+}
+
+static struct dentry *
+zpl_mount(struct file_system_type *fs_type, int flags,
+    const char *osname, void *data)
+{
+	zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };
+
+	struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
+	if (IS_ERR(sb))
+		return (ERR_CAST(sb));
+
+	return (dget(sb->s_root));
+}
+
+static void
+zpl_kill_sb(struct super_block *sb)
+{
+	zfs_preumount(sb);
+	kill_anon_super(sb);
+}
+
+void
+zpl_prune_sb(int64_t nr_to_scan, void *arg)
+{
+	struct super_block *sb = (struct super_block *)arg;
+	int objects = 0;
+
+	(void) -zfs_prune(sb, nr_to_scan, &objects);
+}
+
+const struct super_operations zpl_super_operations = {
+	.alloc_inode		= zpl_inode_alloc,
+	.destroy_inode		= zpl_inode_destroy,
+	.dirty_inode		= zpl_dirty_inode,
+	.write_inode		= NULL,
+	.evict_inode		= zpl_evict_inode,
+	.put_super		= zpl_put_super,
+	.sync_fs		= zpl_sync_fs,
+	.statfs			= zpl_statfs,
+	.remount_fs		= zpl_remount_fs,
+	.show_options		= zpl_show_options,
+	.show_stats		= NULL,
+};
+
+struct file_system_type zpl_fs_type = {
+	.owner			= THIS_MODULE,
+	.name			= ZFS_DRIVER,
+	.mount			= zpl_mount,
+	.kill_sb		= zpl_kill_sb,
+};