5 files changed, 104 insertions, 33 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 77c65a0bea34..8dcfb77678de 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -690,6 +690,17 @@ static void cache_state(struct extent_state *state,
         }
 }
 
+static void uncache_state(struct extent_state **cached_ptr)
+{
+        if (cached_ptr && (*cached_ptr)) {
+                struct extent_state *state = *cached_ptr;
+                if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
+                        *cached_ptr = NULL;
+                        free_extent_state(state);
+                }
+        }
+}
+
 /*
  * set some bits on a range in the tree.  This may require allocations or
  * sleeping, so the gfp mask is used to indicate what is allowed.
@@ -940,10 +951,10 @@ static int clear_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
 }
 
 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
-                        gfp_t mask)
+                        struct extent_state **cached_state, gfp_t mask)
 {
-        return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
-                              NULL, mask);
+        return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
+                              NULL, cached_state, mask);
 }
 
 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
@@ -1012,8 +1023,7 @@ int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
                                 mask);
 }
 
-int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
-                  gfp_t mask)
+int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
 {
         return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
                                 mask);
@@ -1735,6 +1745,9 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
 
         do {
                 struct page *page = bvec->bv_page;
+                struct extent_state *cached = NULL;
+                struct extent_state *state;
+
                 tree = &BTRFS_I(page->mapping->host)->io_tree;
 
                 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
@@ -1749,9 +1762,20 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                 if (++bvec <= bvec_end)
                         prefetchw(&bvec->bv_page->flags);
 
+                spin_lock(&tree->lock);
+                state = find_first_extent_bit_state(tree, start, 0);
+                if (state) {
+                        /*
+                         * take a reference on the state, unlock will drop
+                         * the ref
+                         */
+                        cache_state(state, &cached);
+                }
+                spin_unlock(&tree->lock);
+
                 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
                         ret = tree->ops->readpage_end_io_hook(page, start, end,
-                                                              NULL);
+                                                              state);
                         if (ret)
                                 uptodate = 0;
                 }
@@ -1764,15 +1788,16 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                                         test_bit(BIO_UPTODATE, &bio->bi_flags);
                                 if (err)
                                         uptodate = 0;
+                                uncache_state(&cached);
                                 continue;
                         }
                 }
 
                 if (uptodate) {
-                        set_extent_uptodate(tree, start, end,
+                        set_extent_uptodate(tree, start, end, &cached,
                                             GFP_ATOMIC);
                 }
-                unlock_extent(tree, start, end, GFP_ATOMIC);
+                unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
 
                 if (whole_page) {
                         if (uptodate) {
@@ -1811,6 +1836,7 @@ static void end_bio_extent_preparewrite(struct bio *bio, int err)
 
         do {
                 struct page *page = bvec->bv_page;
+                struct extent_state *cached = NULL;
                 tree = &BTRFS_I(page->mapping->host)->io_tree;
 
                 start = ((u64)page->index << PAGE_CACHE_SHIFT) +
@@ -1821,13 +1847,14 @@ static void end_bio_extent_preparewrite(struct bio *bio, int err)
                         prefetchw(&bvec->bv_page->flags);
 
                 if (uptodate) {
-                        set_extent_uptodate(tree, start, end, GFP_ATOMIC);
+                        set_extent_uptodate(tree, start, end, &cached,
+                                            GFP_ATOMIC);
                 } else {
                         ClearPageUptodate(page);
                         SetPageError(page);
                 }
 
-                unlock_extent(tree, start, end, GFP_ATOMIC);
+                unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
 
         } while (bvec >= bio->bi_io_vec);
 
@@ -2016,14 +2043,17 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
         while (cur <= end) {
                 if (cur >= last_byte) {
                         char *userpage;
+                        struct extent_state *cached = NULL;
+
                         iosize = PAGE_CACHE_SIZE - page_offset;
                         userpage = kmap_atomic(page, KM_USER0);
                         memset(userpage + page_offset, 0, iosize);
                         flush_dcache_page(page);
                         kunmap_atomic(userpage, KM_USER0);
                         set_extent_uptodate(tree, cur, cur + iosize - 1,
-                                            GFP_NOFS);
-                        unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+                                            &cached, GFP_NOFS);
+                        unlock_extent_cached(tree, cur, cur + iosize - 1,
+                                             &cached, GFP_NOFS);
                         break;
                 }
                 em = get_extent(inode, page, page_offset, cur,
@@ -2063,14 +2093,17 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                 /* we've found a hole, just zero and go on */
                 if (block_start == EXTENT_MAP_HOLE) {
                         char *userpage;
+                        struct extent_state *cached = NULL;
+
                         userpage = kmap_atomic(page, KM_USER0);
                         memset(userpage + page_offset, 0, iosize);
                         flush_dcache_page(page);
                         kunmap_atomic(userpage, KM_USER0);
 
                         set_extent_uptodate(tree, cur, cur + iosize - 1,
-                                            GFP_NOFS);
-                        unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+                                            &cached, GFP_NOFS);
+                        unlock_extent_cached(tree, cur, cur + iosize - 1,
+                                             &cached, GFP_NOFS);
                         cur = cur + iosize;
                         page_offset += iosize;
                         continue;
@@ -2789,9 +2822,12 @@ int extent_prepare_write(struct extent_io_tree *tree,
                         iocount++;
                         block_start = block_start + iosize;
                 } else {
-                        set_extent_uptodate(tree, block_start, cur_end,
+                        struct extent_state *cached = NULL;
+
+                        set_extent_uptodate(tree, block_start, cur_end, &cached,
                                             GFP_NOFS);
-                        unlock_extent(tree, block_start, cur_end, GFP_NOFS);
+                        unlock_extent_cached(tree, block_start, cur_end,
+                                             &cached, GFP_NOFS);
                         block_start = cur_end + 1;
                 }
                 page_offset = block_start & (PAGE_CACHE_SIZE - 1);
@@ -3457,7 +3493,7 @@ int set_extent_buffer_uptodate(struct extent_io_tree *tree,
         num_pages = num_extent_pages(eb->start, eb->len);
 
         set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
-                            GFP_NOFS);
+                            NULL, GFP_NOFS);
         for (i = 0; i < num_pages; i++) {
                 page = extent_buffer_page(eb, i);
                 if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
@@ -3885,6 +3921,12 @@ static void move_pages(struct page *dst_page, struct page *src_page,
         kunmap_atomic(dst_kaddr, KM_USER0);
 }
 
+static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
+{
+        unsigned long distance = (src > dst) ? src - dst : dst - src;
+        return distance < len;
+}
+
 static void copy_pages(struct page *dst_page, struct page *src_page,
                        unsigned long dst_off, unsigned long src_off,
                        unsigned long len)
@@ -3892,10 +3934,12 @@ static void copy_pages(struct page *dst_page, struct page *src_page,
         char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
         char *src_kaddr;
 
-        if (dst_page != src_page)
+        if (dst_page != src_page) {
                 src_kaddr = kmap_atomic(src_page, KM_USER1);
-        else
+        } else {
                 src_kaddr = dst_kaddr;
+                BUG_ON(areas_overlap(src_off, dst_off, len));
+        }
 
         memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
         kunmap_atomic(dst_kaddr, KM_USER0);
@@ -3970,7 +4014,7 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
                        "len %lu len %lu\n", dst_offset, len, dst->len);
                 BUG_ON(1);
         }
-        if (dst_offset < src_offset) {
+        if (!areas_overlap(src_offset, dst_offset, len)) {
                 memcpy_extent_buffer(dst, dst_offset, src_offset, len);
                 return;
         }
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index f62c5442835d..af2d7179c372 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -208,7 +208,7 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                    int bits, int exclusive_bits, u64 *failed_start,
                    struct extent_state **cached_state, gfp_t mask);
 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
-                        gfp_t mask);
+                        struct extent_state **cached_state, gfp_t mask);
 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
                    gfp_t mask);
 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 00d59c6a9769..55a6a0b416d7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4541,14 +4541,17 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
         BUG_ON(!path);
 
         inode = new_inode(root->fs_info->sb);
-        if (!inode)
+        if (!inode) {
+                btrfs_free_path(path);
                 return ERR_PTR(-ENOMEM);
+        }
 
         if (dir) {
                 trace_btrfs_inode_request(dir);
 
                 ret = btrfs_set_inode_index(dir, index);
                 if (ret) {
+                        btrfs_free_path(path);
                         iput(inode);
                         return ERR_PTR(ret);
                 }
@@ -5238,7 +5241,7 @@ again:
                         btrfs_mark_buffer_dirty(leaf);
                 }
                 set_extent_uptodate(io_tree, em->start,
-                                    extent_map_end(em) - 1, GFP_NOFS);
+                                    extent_map_end(em) - 1, NULL, GFP_NOFS);
                 goto insert;
         } else {
                 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index f9c93a9ed4a7..f580a3a5d2fc 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2287,7 +2287,7 @@ long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
         struct btrfs_ioctl_space_info space;
         struct btrfs_ioctl_space_info *dest;
         struct btrfs_ioctl_space_info *dest_orig;
-        struct btrfs_ioctl_space_info *user_dest;
+        struct btrfs_ioctl_space_info __user *user_dest;
         struct btrfs_space_info *info;
         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
                        BTRFS_BLOCK_GROUP_SYSTEM,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 58e7de9cc90c..0ac712efcdf2 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -159,7 +159,7 @@ enum {
         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
-        Opt_enospc_debug, Opt_err,
+        Opt_enospc_debug, Opt_subvolrootid, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -189,6 +189,7 @@ static match_table_t tokens = {
         {Opt_clear_cache, "clear_cache"},
         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
         {Opt_enospc_debug, "enospc_debug"},
+        {Opt_subvolrootid, "subvolrootid=%d"},
         {Opt_err, NULL},
 };
 
@@ -232,6 +233,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                         break;
                 case Opt_subvol:
                 case Opt_subvolid:
+                case Opt_subvolrootid:
                 case Opt_device:
                         /*
                          * These are parsed by btrfs_parse_early_options
@@ -388,7 +390,7 @@ out:
  */
 static int btrfs_parse_early_options(const char *options, fmode_t flags,
                 void *holder, char **subvol_name, u64 *subvol_objectid,
-                struct btrfs_fs_devices **fs_devices)
+                u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
 {
         substring_t args[MAX_OPT_ARGS];
         char *opts, *orig, *p;
@@ -429,6 +431,18 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
                                         *subvol_objectid = intarg;
                         }
                         break;
+                case Opt_subvolrootid:
+                        intarg = 0;
+                        error = match_int(&args[0], &intarg);
+                        if (!error) {
+                                /* we want the original fs_tree */
+                                if (!intarg)
+                                        *subvol_rootid =
+                                                BTRFS_FS_TREE_OBJECTID;
+                                else
+                                        *subvol_rootid = intarg;
+                        }
+                        break;
                 case Opt_device:
                         error = btrfs_scan_one_device(match_strdup(&args[0]),
                                         flags, holder, fs_devices);
@@ -736,6 +750,7 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
         fmode_t mode = FMODE_READ;
         char *subvol_name = NULL;
         u64 subvol_objectid = 0;
+        u64 subvol_rootid = 0;
         int error = 0;
 
         if (!(flags & MS_RDONLY))
@@ -743,7 +758,7 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 
         error = btrfs_parse_early_options(data, mode, fs_type,
                                           &subvol_name, &subvol_objectid,
-                                          &fs_devices);
+                                          &subvol_rootid, &fs_devices);
         if (error)
                 return ERR_PTR(error);
 
@@ -807,15 +822,17 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
                 s->s_flags |= MS_ACTIVE;
         }
 
-        root = get_default_root(s, subvol_objectid);
-        if (IS_ERR(root)) {
-                error = PTR_ERR(root);
-                deactivate_locked_super(s);
-                goto error_free_subvol_name;
-        }
         /* if they gave us a subvolume name bind mount into that */
         if (strcmp(subvol_name, ".")) {
                 struct dentry *new_root;
+
+                root = get_default_root(s, subvol_rootid);
+                if (IS_ERR(root)) {
+                        error = PTR_ERR(root);
+                        deactivate_locked_super(s);
+                        goto error_free_subvol_name;
+                }
+
                 mutex_lock(&root->d_inode->i_mutex);
                 new_root = lookup_one_len(subvol_name, root,
                                       strlen(subvol_name));
@@ -836,6 +853,13 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
                 }
                 dput(root);
                 root = new_root;
+        } else {
+                root = get_default_root(s, subvol_objectid);
+                if (IS_ERR(root)) {
+                        error = PTR_ERR(root);
+                        deactivate_locked_super(s);
+                        goto error_free_subvol_name;
+                }
         }
 
         kfree(subvol_name);