1 files changed, 39 insertions, 26 deletions

diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 6ea5f872e2de..f6af76042d80 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -99,7 +99,8 @@ static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
 static int nilfs_ioctl_change_cpmode(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 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;
@@ -109,14 +110,17 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
         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;
 }
 
@@ -297,7 +301,18 @@ static int nilfs_ioctl_move_inode_block(struct inode *inode,
                                (unsigned long long)vdesc->vd_vblocknr);
                 return ret;
         }
-        bh->b_private = vdesc;
+        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;
 }
@@ -335,24 +350,10 @@ static int nilfs_ioctl_move_blocks(struct the_nilfs *nilfs,
         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
                 ret = nilfs_gccache_wait_and_mark_dirty(bh);
                 if (unlikely(ret < 0)) {
-                        if (ret == -EEXIST) {
-                                vdesc = bh->b_private;
-                                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);
-                        }
+                        WARN_ON(ret == -EEXIST);
                         goto failed;
                 }
                 list_del_init(&bh->b_assoc_buffers);
-                bh->b_private = NULL;
                 brelse(bh);
         }
         return nmembs;
@@ -360,7 +361,6 @@ static int nilfs_ioctl_move_blocks(struct the_nilfs *nilfs,
  failed:
         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
                 list_del_init(&bh->b_assoc_buffers);
-                bh->b_private = NULL;
                 brelse(bh);
         }
         return ret;
@@ -442,12 +442,6 @@ int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
         const char *msg;
         int ret;
 
-        ret = nilfs_ioctl_move_blocks(nilfs, &argv[0], kbufs[0]);
-        if (ret < 0) {
-                msg = "cannot read source blocks";
-                goto failed;
-        }
-
         ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
         if (ret < 0) {
                 /*
@@ -477,7 +471,6 @@ int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
         return 0;
 
  failed:
-        nilfs_remove_all_gcinode(nilfs);
         printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
                msg, ret);
         return ret;
@@ -548,7 +541,27 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
                 }
         }
 
-        ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
+        /*
+         * 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)