fs/nilfs2/ioctl.c - kernel/msm - Gitiles

 /*
  * ioctl.c - NILFS ioctl operations.
  *
  * Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  *
  * Written by Koji Sato <koji@osrg.net>.
  */

 #include <linux/fs.h>
 #include <linux/wait.h>
 #include <linux/smp_lock.h>	/* lock_kernel(), unlock_kernel() */
 #include <linux/capability.h>	/* capable() */
 #include <linux/uaccess.h>	/* copy_from_user(), copy_to_user() */
 #include <linux/vmalloc.h>
 #include <linux/nilfs2_fs.h>
 #include "nilfs.h"
 #include "segment.h"
 #include "bmap.h"
 #include "cpfile.h"
 #include "sufile.h"
 #include "dat.h"


 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
 				 struct nilfs_argv *argv, int dir,
 				 ssize_t (*dofunc)(struct the_nilfs *,
 						   __u64 *, int,
 						   void *, size_t, size_t))
 {
 	void *buf;
 	void __user *base = (void __user *)(unsigned long)argv->v_base;
 	size_t maxmembs, total, n;
 	ssize_t nr;
 	int ret, i;
 	__u64 pos, ppos;

 	if (argv->v_nmembs == 0)
 		return 0;

 	if (argv->v_size > PAGE_SIZE)
 		return -EINVAL;

 	buf = (void *)__get_free_pages(GFP_NOFS, 0);
 	if (unlikely(!buf))
 		return -ENOMEM;
 	maxmembs = PAGE_SIZE / argv->v_size;

 	ret = 0;
 	total = 0;
 	pos = argv->v_index;
 	for (i = 0; i < argv->v_nmembs; i += n) {
 		n = (argv->v_nmembs - i < maxmembs) ?
 			argv->v_nmembs - i : maxmembs;
 		if ((dir & _IOC_WRITE) &&
 		    copy_from_user(buf, base + argv->v_size * i,
 				   argv->v_size * n)) {
 			ret = -EFAULT;
 			break;
 		}
 		ppos = pos;
 		nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
 			       n);
 		if (nr < 0) {
 			ret = nr;
 			break;
 		}
 		if ((dir & _IOC_READ) &&
 		    copy_to_user(base + argv->v_size * i, buf,
 				 argv->v_size * nr)) {
 			ret = -EFAULT;
 			break;
 		}
 		total += nr;
 		if ((size_t)nr < n)
 			break;
 		if (pos == ppos)
 			pos += n;
 	}
 	argv->v_nmembs = total;

 	free_pages((unsigned long)buf, 0);
 	return ret;
 }

 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
 				     unsigned int cmd, void __user *argp)
 {
 	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 	struct inode *cpfile = nilfs->ns_cpfile;
 	struct nilfs_transaction_info ti;
 	struct nilfs_cpmode cpmode;
 	int ret;

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
 		return -EFAULT;

 	mutex_lock(&nilfs->ns_mount_mutex);
 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
 	ret = nilfs_cpfile_change_cpmode(
 		cpfile, cpmode.cm_cno, cpmode.cm_mode);
 	if (unlikely(ret < 0)) {
 		nilfs_transaction_abort(inode->i_sb);
 		mutex_unlock(&nilfs->ns_mount_mutex);
 		return ret;
 	}
 	nilfs_transaction_commit(inode->i_sb); /* never fails */
 	mutex_unlock(&nilfs->ns_mount_mutex);
 	return ret;
 }

 static int
 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
 			      unsigned int cmd, void __user *argp)
 {
 	struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
 	struct nilfs_transaction_info ti;
 	__u64 cno;
 	int ret;

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (copy_from_user(&cno, argp, sizeof(cno)))
 		return -EFAULT;

 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
 	ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
 	if (unlikely(ret < 0)) {
 		nilfs_transaction_abort(inode->i_sb);
 		return ret;
 	}
 	nilfs_transaction_commit(inode->i_sb); /* never fails */
 	return ret;
 }

 static ssize_t
 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 			  void *buf, size_t size, size_t nmembs)
 {
 	int ret;

 	down_read(&nilfs->ns_segctor_sem);
 	ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
 				      size, nmembs);
 	up_read(&nilfs->ns_segctor_sem);
 	return ret;
 }

 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
 				  unsigned int cmd, void __user *argp)
 {
 	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 	struct nilfs_cpstat cpstat;
 	int ret;

 	down_read(&nilfs->ns_segctor_sem);
 	ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
 	up_read(&nilfs->ns_segctor_sem);
 	if (ret < 0)
 		return ret;

 	if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
 		ret = -EFAULT;
 	return ret;
 }

 static ssize_t
 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 			  void *buf, size_t size, size_t nmembs)
 {
 	int ret;

 	down_read(&nilfs->ns_segctor_sem);
 	ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
 				      nmembs);
 	up_read(&nilfs->ns_segctor_sem);
 	return ret;
 }

 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
 				  unsigned int cmd, void __user *argp)
 {
 	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 	struct nilfs_sustat sustat;
 	int ret;

 	down_read(&nilfs->ns_segctor_sem);
 	ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
 	up_read(&nilfs->ns_segctor_sem);
 	if (ret < 0)
 		return ret;

 	if (copy_to_user(argp, &sustat, sizeof(sustat)))
 		ret = -EFAULT;
 	return ret;
 }

 static ssize_t
 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 			 void *buf, size_t size, size_t nmembs)
 {
 	int ret;

 	down_read(&nilfs->ns_segctor_sem);
 	ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, size, nmembs);
 	up_read(&nilfs->ns_segctor_sem);
 	return ret;
 }

 static ssize_t
 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
 			  void *buf, size_t size, size_t nmembs)
 {
 	struct inode *dat = nilfs_dat_inode(nilfs);
 	struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
 	struct nilfs_bdesc *bdescs = buf;
 	int ret, i;

 	down_read(&nilfs->ns_segctor_sem);
 	for (i = 0; i < nmembs; i++) {
 		ret = nilfs_bmap_lookup_at_level(bmap,
 						 bdescs[i].bd_offset,
 						 bdescs[i].bd_level + 1,
 						 &bdescs[i].bd_blocknr);
 		if (ret < 0) {
 			if (ret != -ENOENT) {
 				up_read(&nilfs->ns_segctor_sem);
 				return ret;
 			}
 			bdescs[i].bd_blocknr = 0;
 		}
 	}
 	up_read(&nilfs->ns_segctor_sem);
 	return nmembs;
 }

 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
 				  unsigned int cmd, void __user *argp)
 {
 	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 	struct nilfs_argv argv;
 	int ret;

 	if (copy_from_user(&argv, argp, sizeof(argv)))
 		return -EFAULT;

 	if (argv.v_size != sizeof(struct nilfs_bdesc))
 		return -EINVAL;

 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
 				    nilfs_ioctl_do_get_bdescs);
 	if (ret < 0)
 		return ret;

 	if (copy_to_user(argp, &argv, sizeof(argv)))
 		ret = -EFAULT;
 	return ret;
 }

 static int nilfs_ioctl_move_inode_block(struct inode *inode,
 					struct nilfs_vdesc *vdesc,
 					struct list_head *buffers)
 {
 	struct buffer_head *bh;
 	int ret;

 	if (vdesc->vd_flags == 0)
 		ret = nilfs_gccache_submit_read_data(
 			inode, vdesc->vd_offset, vdesc->vd_blocknr,
 			vdesc->vd_vblocknr, &bh);
 	else
 		ret = nilfs_gccache_submit_read_node(
 			inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);

 	if (unlikely(ret < 0)) {
 		if (ret == -ENOENT)
 			printk(KERN_CRIT
 			       "%s: invalid virtual block address (%s): "
 			       "ino=%llu, cno=%llu, offset=%llu, "
 			       "blocknr=%llu, vblocknr=%llu\n",
 			       __func__, vdesc->vd_flags ? "node" : "data",
 			       (unsigned long long)vdesc->vd_ino,
 			       (unsigned long long)vdesc->vd_cno,
 			       (unsigned long long)vdesc->vd_offset,
 			       (unsigned long long)vdesc->vd_blocknr,
 			       (unsigned long long)vdesc->vd_vblocknr);
 		return ret;
 	}
 	if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
 		printk(KERN_CRIT "%s: conflicting %s buffer: ino=%llu, "
 		       "cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu\n",
 		       __func__, vdesc->vd_flags ? "node" : "data",
 		       (unsigned long long)vdesc->vd_ino,
 		       (unsigned long long)vdesc->vd_cno,
 		       (unsigned long long)vdesc->vd_offset,
 		       (unsigned long long)vdesc->vd_blocknr,
 		       (unsigned long long)vdesc->vd_vblocknr);
 		brelse(bh);
 		return -EEXIST;
 	}
 	list_add_tail(&bh->b_assoc_buffers, buffers);
 	return 0;
 }

 static int nilfs_ioctl_move_blocks(struct the_nilfs *nilfs,
 				   struct nilfs_argv *argv, void *buf)
 {
 	size_t nmembs = argv->v_nmembs;
 	struct inode *inode;
 	struct nilfs_vdesc *vdesc;
 	struct buffer_head *bh, *n;
 	LIST_HEAD(buffers);
 	ino_t ino;
 	__u64 cno;
 	int i, ret;

 	for (i = 0, vdesc = buf; i < nmembs; ) {
 		ino = vdesc->vd_ino;
 		cno = vdesc->vd_cno;
 		inode = nilfs_gc_iget(nilfs, ino, cno);
 		if (unlikely(inode == NULL)) {
 			ret = -ENOMEM;
 			goto failed;
 		}
 		do {
 			ret = nilfs_ioctl_move_inode_block(inode, vdesc,
 							   &buffers);
 			if (unlikely(ret < 0))
 				goto failed;
 			vdesc++;
 		} while (++i < nmembs &&
 			 vdesc->vd_ino == ino && vdesc->vd_cno == cno);
 	}

 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
 		ret = nilfs_gccache_wait_and_mark_dirty(bh);
 		if (unlikely(ret < 0)) {
 			WARN_ON(ret == -EEXIST);
 			goto failed;
 		}
 		list_del_init(&bh->b_assoc_buffers);
 		brelse(bh);
 	}
 	return nmembs;

  failed:
 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
 		list_del_init(&bh->b_assoc_buffers);
 		brelse(bh);
 	}
 	return ret;
 }

 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
 					  struct nilfs_argv *argv, void *buf)
 {
 	size_t nmembs = argv->v_nmembs;
 	struct inode *cpfile = nilfs->ns_cpfile;
 	struct nilfs_period *periods = buf;
 	int ret, i;

 	for (i = 0; i < nmembs; i++) {
 		ret = nilfs_cpfile_delete_checkpoints(
 			cpfile, periods[i].p_start, periods[i].p_end);
 		if (ret < 0)
 			return ret;
 	}
 	return nmembs;
 }

 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
 				      struct nilfs_argv *argv, void *buf)
 {
 	size_t nmembs = argv->v_nmembs;
 	int ret;

 	ret = nilfs_dat_freev(nilfs_dat_inode(nilfs), buf, nmembs);

 	return (ret < 0) ? ret : nmembs;
 }

 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
 					 struct nilfs_argv *argv, void *buf)
 {
 	size_t nmembs = argv->v_nmembs;
 	struct inode *dat = nilfs_dat_inode(nilfs);
 	struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
 	struct nilfs_bdesc *bdescs = buf;
 	int ret, i;

 	for (i = 0; i < nmembs; i++) {
 		/* XXX: use macro or inline func to check liveness */
 		ret = nilfs_bmap_lookup_at_level(bmap,
 						 bdescs[i].bd_offset,
 						 bdescs[i].bd_level + 1,
 						 &bdescs[i].bd_blocknr);
 		if (ret < 0) {
 			if (ret != -ENOENT)
 				return ret;
 			bdescs[i].bd_blocknr = 0;
 		}
 		if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
 			/* skip dead block */
 			continue;
 		if (bdescs[i].bd_level == 0) {
 			ret = nilfs_mdt_mark_block_dirty(dat,
 							 bdescs[i].bd_offset);
 			if (ret < 0) {
 				WARN_ON(ret == -ENOENT);
 				return ret;
 			}
 		} else {
 			ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
 					      bdescs[i].bd_level);
 			if (ret < 0) {
 				WARN_ON(ret == -ENOENT);
 				return ret;
 			}
 		}
 	}
 	return nmembs;
 }

 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
 				       struct nilfs_argv *argv, void **kbufs)
 {
 	const char *msg;
 	int ret;

 	ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
 	if (ret < 0) {
 		/*
 		 * can safely abort because checkpoints can be removed
 		 * independently.
 		 */
 		msg = "cannot delete checkpoints";
 		goto failed;
 	}
 	ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
 	if (ret < 0) {
 		/*
 		 * can safely abort because DAT file is updated atomically
 		 * using a copy-on-write technique.
 		 */
 		msg = "cannot delete virtual blocks from DAT file";
 		goto failed;
 	}
 	ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
 	if (ret < 0) {
 		/*
 		 * can safely abort because the operation is nondestructive.
 		 */
 		msg = "cannot mark copying blocks dirty";
 		goto failed;
 	}
 	return 0;

  failed:
 	printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
 	       msg, ret);
 	return ret;
 }

 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
 				      unsigned int cmd, void __user *argp)
 {
 	struct nilfs_argv argv[5];
 	const static size_t argsz[5] = {
 		sizeof(struct nilfs_vdesc),
 		sizeof(struct nilfs_period),
 		sizeof(__u64),
 		sizeof(struct nilfs_bdesc),
 		sizeof(__u64),
 	};
 	void __user *base;
 	void *kbufs[5];
 	struct the_nilfs *nilfs;
 	size_t len, nsegs;
 	int n, ret;

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;

 	if (copy_from_user(argv, argp, sizeof(argv)))
 		return -EFAULT;

 	nsegs = argv[4].v_nmembs;
 	if (argv[4].v_size != argsz[4])
 		return -EINVAL;
 	/*
 	 * argv[4] points to segment numbers this ioctl cleans.  We
 	 * use kmalloc() for its buffer because memory used for the
 	 * segment numbers is enough small.
 	 */
 	kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
 			       nsegs * sizeof(__u64));
 	if (IS_ERR(kbufs[4]))
 		return PTR_ERR(kbufs[4]);

 	nilfs = NILFS_SB(inode->i_sb)->s_nilfs;

 	for (n = 0; n < 4; n++) {
 		ret = -EINVAL;
 		if (argv[n].v_size != argsz[n])
 			goto out_free;

 		if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
 			goto out_free;

 		len = argv[n].v_size * argv[n].v_nmembs;
 		base = (void __user *)(unsigned long)argv[n].v_base;
 		if (len == 0) {
 			kbufs[n] = NULL;
 			continue;
 		}

 		kbufs[n] = vmalloc(len);
 		if (!kbufs[n]) {
 			ret = -ENOMEM;
 			goto out_free;
 		}
 		if (copy_from_user(kbufs[n], base, len)) {
 			ret = -EFAULT;
 			vfree(kbufs[n]);
 			goto out_free;
 		}
 	}

 	/*
 	 * nilfs_ioctl_move_blocks() will call nilfs_gc_iget(),
 	 * which will operates an inode list without blocking.
 	 * To protect the list from concurrent operations,
 	 * nilfs_ioctl_move_blocks should be atomic operation.
 	 */
 	if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
 		ret = -EBUSY;
 		goto out_free;
 	}

 	ret = nilfs_ioctl_move_blocks(nilfs, &argv[0], kbufs[0]);
 	if (ret < 0)
 		printk(KERN_ERR "NILFS: GC failed during preparation: "
 			"cannot read source blocks: err=%d\n", ret);
 	else
 		ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);

 	if (ret < 0)
 		nilfs_remove_all_gcinode(nilfs);
 	clear_nilfs_gc_running(nilfs);

  out_free:
 	while (--n >= 0)
 		vfree(kbufs[n]);
 	kfree(kbufs[4]);
 	return ret;
 }

 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
 			    unsigned int cmd, void __user *argp)
 {
 	__u64 cno;
 	int ret;

 	ret = nilfs_construct_segment(inode->i_sb);
 	if (ret < 0)
 		return ret;

 	if (argp != NULL) {
 		cno = NILFS_SB(inode->i_sb)->s_nilfs->ns_cno - 1;
 		if (copy_to_user(argp, &cno, sizeof(cno)))
 			return -EFAULT;
 	}
 	return 0;
 }

 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
 				unsigned int cmd, void __user *argp,
 				size_t membsz,
 				ssize_t (*dofunc)(struct the_nilfs *,
 						  __u64 *, int,
 						  void *, size_t, size_t))

 {
 	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 	struct nilfs_argv argv;
 	int ret;

 	if (copy_from_user(&argv, argp, sizeof(argv)))
 		return -EFAULT;

 	if (argv.v_size < membsz)
 		return -EINVAL;

 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
 	if (ret < 0)
 		return ret;

 	if (copy_to_user(argp, &argv, sizeof(argv)))
 		ret = -EFAULT;
 	return ret;
 }

 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = filp->f_dentry->d_inode;
 	void __user *argp = (void * __user *)arg;

 	switch (cmd) {
 	case NILFS_IOCTL_CHANGE_CPMODE:
 		return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
 	case NILFS_IOCTL_DELETE_CHECKPOINT:
 		return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
 	case NILFS_IOCTL_GET_CPINFO:
 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 					    sizeof(struct nilfs_cpinfo),
 					    nilfs_ioctl_do_get_cpinfo);
 	case NILFS_IOCTL_GET_CPSTAT:
 		return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
 	case NILFS_IOCTL_GET_SUINFO:
 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 					    sizeof(struct nilfs_suinfo),
 					    nilfs_ioctl_do_get_suinfo);
 	case NILFS_IOCTL_GET_SUSTAT:
 		return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
 	case NILFS_IOCTL_GET_VINFO:
 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 					    sizeof(struct nilfs_vinfo),
 					    nilfs_ioctl_do_get_vinfo);
 	case NILFS_IOCTL_GET_BDESCS:
 		return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
 	case NILFS_IOCTL_CLEAN_SEGMENTS:
 		return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
 	case NILFS_IOCTL_SYNC:
 		return nilfs_ioctl_sync(inode, filp, cmd, argp);
 	default:
 		return -ENOTTY;
 	}
 }
	/*
	* ioctl.c - NILFS ioctl operations.
	*
	* Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*
	* Written by Koji Sato <koji@osrg.net>.
	*/

	#include <linux/fs.h>
	#include <linux/wait.h>
	#include <linux/smp_lock.h> /* lock_kernel(), unlock_kernel() */
	#include <linux/capability.h> /* capable() */
	#include <linux/uaccess.h> /* copy_from_user(), copy_to_user() */
	#include <linux/vmalloc.h>
	#include <linux/nilfs2_fs.h>
	#include "nilfs.h"
	#include "segment.h"
	#include "bmap.h"
	#include "cpfile.h"
	#include "sufile.h"
	#include "dat.h"


	static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
	struct nilfs_argv *argv, int dir,
	ssize_t (dofunc)(struct the_nilfs ,
	__u64 *, int,
	void *, size_t, size_t))
	{
	void *buf;
	void __user base = (void __user )(unsigned long)argv->v_base;
	size_t maxmembs, total, n;
	ssize_t nr;
	int ret, i;
	__u64 pos, ppos;

	if (argv->v_nmembs == 0)
	return 0;

	if (argv->v_size > PAGE_SIZE)
	return -EINVAL;

	buf = (void *)__get_free_pages(GFP_NOFS, 0);
	if (unlikely(!buf))
	return -ENOMEM;
	maxmembs = PAGE_SIZE / argv->v_size;

	ret = 0;
	total = 0;
	pos = argv->v_index;
	for (i = 0; i < argv->v_nmembs; i += n) {
	n = (argv->v_nmembs - i < maxmembs) ?
	argv->v_nmembs - i : maxmembs;
	if ((dir & _IOC_WRITE) &&
	copy_from_user(buf, base + argv->v_size * i,
	argv->v_size * n)) {
	ret = -EFAULT;
	break;
	}
	ppos = pos;
	nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
	n);
	if (nr < 0) {
	ret = nr;
	break;
	}
	if ((dir & _IOC_READ) &&
	copy_to_user(base + argv->v_size * i, buf,
	argv->v_size * nr)) {
	ret = -EFAULT;
	break;
	}
	total += nr;
	if ((size_t)nr < n)
	break;
	if (pos == ppos)
	pos += n;
	}
	argv->v_nmembs = total;

	free_pages((unsigned long)buf, 0);
	return ret;
	}

	static int nilfs_ioctl_change_cpmode(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
	struct inode *cpfile = nilfs->ns_cpfile;
	struct nilfs_transaction_info ti;
	struct nilfs_cpmode cpmode;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;
	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
	return -EFAULT;

	mutex_lock(&nilfs->ns_mount_mutex);
	nilfs_transaction_begin(inode->i_sb, &ti, 0);
	ret = nilfs_cpfile_change_cpmode(
	cpfile, cpmode.cm_cno, cpmode.cm_mode);
	if (unlikely(ret < 0)) {
	nilfs_transaction_abort(inode->i_sb);
	mutex_unlock(&nilfs->ns_mount_mutex);
	return ret;
	}
	nilfs_transaction_commit(inode->i_sb); /* never fails */
	mutex_unlock(&nilfs->ns_mount_mutex);
	return ret;
	}

	static int
	nilfs_ioctl_delete_checkpoint(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
	struct nilfs_transaction_info ti;
	__u64 cno;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;
	if (copy_from_user(&cno, argp, sizeof(cno)))
	return -EFAULT;

	nilfs_transaction_begin(inode->i_sb, &ti, 0);
	ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
	if (unlikely(ret < 0)) {
	nilfs_transaction_abort(inode->i_sb);
	return ret;
	}
	nilfs_transaction_commit(inode->i_sb); /* never fails */
	return ret;
	}

	static ssize_t
	nilfs_ioctl_do_get_cpinfo(struct the_nilfs nilfs, __u64 posp, int flags,
	void *buf, size_t size, size_t nmembs)
	{
	int ret;

	down_read(&nilfs->ns_segctor_sem);
	ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
	size, nmembs);
	up_read(&nilfs->ns_segctor_sem);
	return ret;
	}

	static int nilfs_ioctl_get_cpstat(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
	struct nilfs_cpstat cpstat;
	int ret;

	down_read(&nilfs->ns_segctor_sem);
	ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
	up_read(&nilfs->ns_segctor_sem);
	if (ret < 0)
	return ret;

	if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
	ret = -EFAULT;
	return ret;
	}

	static ssize_t
	nilfs_ioctl_do_get_suinfo(struct the_nilfs nilfs, __u64 posp, int flags,
	void *buf, size_t size, size_t nmembs)
	{
	int ret;

	down_read(&nilfs->ns_segctor_sem);
	ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
	nmembs);
	up_read(&nilfs->ns_segctor_sem);
	return ret;
	}

	static int nilfs_ioctl_get_sustat(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
	struct nilfs_sustat sustat;
	int ret;

	down_read(&nilfs->ns_segctor_sem);
	ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
	up_read(&nilfs->ns_segctor_sem);
	if (ret < 0)
	return ret;

	if (copy_to_user(argp, &sustat, sizeof(sustat)))
	ret = -EFAULT;
	return ret;
	}

	static ssize_t
	nilfs_ioctl_do_get_vinfo(struct the_nilfs nilfs, __u64 posp, int flags,
	void *buf, size_t size, size_t nmembs)
	{
	int ret;

	down_read(&nilfs->ns_segctor_sem);
	ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, size, nmembs);
	up_read(&nilfs->ns_segctor_sem);
	return ret;
	}

	static ssize_t
	nilfs_ioctl_do_get_bdescs(struct the_nilfs nilfs, __u64 posp, int flags,
	void *buf, size_t size, size_t nmembs)
	{
	struct inode *dat = nilfs_dat_inode(nilfs);
	struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
	struct nilfs_bdesc *bdescs = buf;
	int ret, i;

	down_read(&nilfs->ns_segctor_sem);
	for (i = 0; i < nmembs; i++) {
	ret = nilfs_bmap_lookup_at_level(bmap,
	bdescs[i].bd_offset,
	bdescs[i].bd_level + 1,
	&bdescs[i].bd_blocknr);
	if (ret < 0) {
	if (ret != -ENOENT) {
	up_read(&nilfs->ns_segctor_sem);
	return ret;
	}
	bdescs[i].bd_blocknr = 0;
	}
	}
	up_read(&nilfs->ns_segctor_sem);
	return nmembs;
	}

	static int nilfs_ioctl_get_bdescs(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
	struct nilfs_argv argv;
	int ret;

	if (copy_from_user(&argv, argp, sizeof(argv)))
	return -EFAULT;

	if (argv.v_size != sizeof(struct nilfs_bdesc))
	return -EINVAL;

	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
	nilfs_ioctl_do_get_bdescs);
	if (ret < 0)
	return ret;

	if (copy_to_user(argp, &argv, sizeof(argv)))
	ret = -EFAULT;
	return ret;
	}

	static int nilfs_ioctl_move_inode_block(struct inode *inode,
	struct nilfs_vdesc *vdesc,
	struct list_head *buffers)
	{
	struct buffer_head *bh;
	int ret;

	if (vdesc->vd_flags == 0)
	ret = nilfs_gccache_submit_read_data(
	inode, vdesc->vd_offset, vdesc->vd_blocknr,
	vdesc->vd_vblocknr, &bh);
	else
	ret = nilfs_gccache_submit_read_node(
	inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);

	if (unlikely(ret < 0)) {
	if (ret == -ENOENT)
	printk(KERN_CRIT
	"%s: invalid virtual block address (%s): "
	"ino=%llu, cno=%llu, offset=%llu, "
	"blocknr=%llu, vblocknr=%llu\n",
	__func__, vdesc->vd_flags ? "node" : "data",
	(unsigned long long)vdesc->vd_ino,
	(unsigned long long)vdesc->vd_cno,
	(unsigned long long)vdesc->vd_offset,
	(unsigned long long)vdesc->vd_blocknr,
	(unsigned long long)vdesc->vd_vblocknr);
	return ret;
	}
	if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
	printk(KERN_CRIT "%s: conflicting %s buffer: ino=%llu, "
	"cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu\n",
	__func__, vdesc->vd_flags ? "node" : "data",
	(unsigned long long)vdesc->vd_ino,
	(unsigned long long)vdesc->vd_cno,
	(unsigned long long)vdesc->vd_offset,
	(unsigned long long)vdesc->vd_blocknr,
	(unsigned long long)vdesc->vd_vblocknr);
	brelse(bh);
	return -EEXIST;
	}
	list_add_tail(&bh->b_assoc_buffers, buffers);
	return 0;
	}

	static int nilfs_ioctl_move_blocks(struct the_nilfs *nilfs,
	struct nilfs_argv argv, void buf)
	{
	size_t nmembs = argv->v_nmembs;
	struct inode *inode;
	struct nilfs_vdesc *vdesc;
	struct buffer_head bh, n;
	LIST_HEAD(buffers);
	ino_t ino;
	__u64 cno;
	int i, ret;

	for (i = 0, vdesc = buf; i < nmembs; ) {
	ino = vdesc->vd_ino;
	cno = vdesc->vd_cno;
	inode = nilfs_gc_iget(nilfs, ino, cno);
	if (unlikely(inode == NULL)) {
	ret = -ENOMEM;
	goto failed;
	}
	do {
	ret = nilfs_ioctl_move_inode_block(inode, vdesc,
	&buffers);
	if (unlikely(ret < 0))
	goto failed;
	vdesc++;
	} while (++i < nmembs &&
	vdesc->vd_ino == ino && vdesc->vd_cno == cno);
	}

	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
	ret = nilfs_gccache_wait_and_mark_dirty(bh);
	if (unlikely(ret < 0)) {
	WARN_ON(ret == -EEXIST);
	goto failed;
	}
	list_del_init(&bh->b_assoc_buffers);
	brelse(bh);
	}
	return nmembs;

	failed:
	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
	list_del_init(&bh->b_assoc_buffers);
	brelse(bh);
	}
	return ret;
	}

	static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
	struct nilfs_argv argv, void buf)
	{
	size_t nmembs = argv->v_nmembs;
	struct inode *cpfile = nilfs->ns_cpfile;
	struct nilfs_period *periods = buf;
	int ret, i;

	for (i = 0; i < nmembs; i++) {
	ret = nilfs_cpfile_delete_checkpoints(
	cpfile, periods[i].p_start, periods[i].p_end);
	if (ret < 0)
	return ret;
	}
	return nmembs;
	}

	static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
	struct nilfs_argv argv, void buf)
	{
	size_t nmembs = argv->v_nmembs;
	int ret;

	ret = nilfs_dat_freev(nilfs_dat_inode(nilfs), buf, nmembs);

	return (ret < 0) ? ret : nmembs;
	}

	static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
	struct nilfs_argv argv, void buf)
	{
	size_t nmembs = argv->v_nmembs;
	struct inode *dat = nilfs_dat_inode(nilfs);
	struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
	struct nilfs_bdesc *bdescs = buf;
	int ret, i;

	for (i = 0; i < nmembs; i++) {
	/* XXX: use macro or inline func to check liveness */
	ret = nilfs_bmap_lookup_at_level(bmap,
	bdescs[i].bd_offset,
	bdescs[i].bd_level + 1,
	&bdescs[i].bd_blocknr);
	if (ret < 0) {
	if (ret != -ENOENT)
	return ret;
	bdescs[i].bd_blocknr = 0;
	}
	if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
	/* skip dead block */
	continue;
	if (bdescs[i].bd_level == 0) {
	ret = nilfs_mdt_mark_block_dirty(dat,
	bdescs[i].bd_offset);
	if (ret < 0) {
	WARN_ON(ret == -ENOENT);
	return ret;
	}
	} else {
	ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
	bdescs[i].bd_level);
	if (ret < 0) {
	WARN_ON(ret == -ENOENT);
	return ret;
	}
	}
	}
	return nmembs;
	}

	int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
	struct nilfs_argv argv, void *kbufs)
	{
	const char *msg;
	int ret;

	ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
	if (ret < 0) {
	/*
	* can safely abort because checkpoints can be removed
	* independently.
	*/
	msg = "cannot delete checkpoints";
	goto failed;
	}
	ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
	if (ret < 0) {
	/*
	* can safely abort because DAT file is updated atomically
	* using a copy-on-write technique.
	*/
	msg = "cannot delete virtual blocks from DAT file";
	goto failed;
	}
	ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
	if (ret < 0) {
	/*
	* can safely abort because the operation is nondestructive.
	*/
	msg = "cannot mark copying blocks dirty";
	goto failed;
	}
	return 0;

	failed:
	printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
	msg, ret);
	return ret;
	}

	static int nilfs_ioctl_clean_segments(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	struct nilfs_argv argv[5];
	const static size_t argsz[5] = {
	sizeof(struct nilfs_vdesc),
	sizeof(struct nilfs_period),
	sizeof(__u64),
	sizeof(struct nilfs_bdesc),
	sizeof(__u64),
	};
	void __user *base;
	void *kbufs[5];
	struct the_nilfs *nilfs;
	size_t len, nsegs;
	int n, ret;

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;

	if (copy_from_user(argv, argp, sizeof(argv)))
	return -EFAULT;

	nsegs = argv[4].v_nmembs;
	if (argv[4].v_size != argsz[4])
	return -EINVAL;
	/*
	* argv[4] points to segment numbers this ioctl cleans. We
	* use kmalloc() for its buffer because memory used for the
	* segment numbers is enough small.
	*/
	kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
	nsegs * sizeof(__u64));
	if (IS_ERR(kbufs[4]))
	return PTR_ERR(kbufs[4]);

	nilfs = NILFS_SB(inode->i_sb)->s_nilfs;

	for (n = 0; n < 4; n++) {
	ret = -EINVAL;
	if (argv[n].v_size != argsz[n])
	goto out_free;

	if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
	goto out_free;

	len = argv[n].v_size * argv[n].v_nmembs;
	base = (void __user *)(unsigned long)argv[n].v_base;
	if (len == 0) {
	kbufs[n] = NULL;
	continue;
	}

	kbufs[n] = vmalloc(len);
	if (!kbufs[n]) {
	ret = -ENOMEM;
	goto out_free;
	}
	if (copy_from_user(kbufs[n], base, len)) {
	ret = -EFAULT;
	vfree(kbufs[n]);
	goto out_free;
	}
	}

	/*
	* nilfs_ioctl_move_blocks() will call nilfs_gc_iget(),
	* which will operates an inode list without blocking.
	* To protect the list from concurrent operations,
	* nilfs_ioctl_move_blocks should be atomic operation.
	*/
	if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
	ret = -EBUSY;
	goto out_free;
	}

	ret = nilfs_ioctl_move_blocks(nilfs, &argv[0], kbufs[0]);
	if (ret < 0)
	printk(KERN_ERR "NILFS: GC failed during preparation: "
	"cannot read source blocks: err=%d\n", ret);
	else
	ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);

	if (ret < 0)
	nilfs_remove_all_gcinode(nilfs);
	clear_nilfs_gc_running(nilfs);

	out_free:
	while (--n >= 0)
	vfree(kbufs[n]);
	kfree(kbufs[4]);
	return ret;
	}

	static int nilfs_ioctl_sync(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp)
	{
	__u64 cno;
	int ret;

	ret = nilfs_construct_segment(inode->i_sb);
	if (ret < 0)
	return ret;

	if (argp != NULL) {
	cno = NILFS_SB(inode->i_sb)->s_nilfs->ns_cno - 1;
	if (copy_to_user(argp, &cno, sizeof(cno)))
	return -EFAULT;
	}
	return 0;
	}

	static int nilfs_ioctl_get_info(struct inode inode, struct file filp,
	unsigned int cmd, void __user *argp,
	size_t membsz,
	ssize_t (dofunc)(struct the_nilfs ,
	__u64 *, int,
	void *, size_t, size_t))

	{
	struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
	struct nilfs_argv argv;
	int ret;

	if (copy_from_user(&argv, argp, sizeof(argv)))
	return -EFAULT;

	if (argv.v_size < membsz)
	return -EINVAL;

	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
	if (ret < 0)
	return ret;

	if (copy_to_user(argp, &argv, sizeof(argv)))
	ret = -EFAULT;
	return ret;
	}

	long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = filp->f_dentry->d_inode;
	void __user argp = (void __user *)arg;

	switch (cmd) {
	case NILFS_IOCTL_CHANGE_CPMODE:
	return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
	case NILFS_IOCTL_DELETE_CHECKPOINT:
	return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
	case NILFS_IOCTL_GET_CPINFO:
	return nilfs_ioctl_get_info(inode, filp, cmd, argp,
	sizeof(struct nilfs_cpinfo),
	nilfs_ioctl_do_get_cpinfo);
	case NILFS_IOCTL_GET_CPSTAT:
	return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
	case NILFS_IOCTL_GET_SUINFO:
	return nilfs_ioctl_get_info(inode, filp, cmd, argp,
	sizeof(struct nilfs_suinfo),
	nilfs_ioctl_do_get_suinfo);
	case NILFS_IOCTL_GET_SUSTAT:
	return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
	case NILFS_IOCTL_GET_VINFO:
	return nilfs_ioctl_get_info(inode, filp, cmd, argp,
	sizeof(struct nilfs_vinfo),
	nilfs_ioctl_do_get_vinfo);
	case NILFS_IOCTL_GET_BDESCS:
	return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
	case NILFS_IOCTL_CLEAN_SEGMENTS:
	return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
	case NILFS_IOCTL_SYNC:
	return nilfs_ioctl_sync(inode, filp, cmd, argp);
	default:
	return -ENOTTY;
	}
	}