Btrfs: kill the start argument to read_extent_buffer_pages

Nobody uses this, it makes no sense to do partial reads of extent buffers.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

3 files changed, 15 insertions, 28 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f92bfa8ffd41..e4c2428cee85 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -442,7 +442,7 @@ static int btrfs_check_super_csum(char *raw_disk_sb)
  */
 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
                                           struct extent_buffer *eb,
-                                          u64 start, u64 parent_transid)
+                                          u64 parent_transid)
 {
         struct extent_io_tree *io_tree;
         int failed = 0;
@@ -454,8 +454,7 @@ static int btree_read_extent_buffer_pages(struct btrfs_root *root,
         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
         while (1) {
-                ret = read_extent_buffer_pages(io_tree, eb, start,
-                                               WAIT_COMPLETE,
+                ret = read_extent_buffer_pages(io_tree, eb, WAIT_COMPLETE,
                                                btree_get_extent, mirror_num);
                 if (!ret) {
                         if (!verify_parent_transid(io_tree, eb,
@@ -1132,7 +1131,7 @@ void readahead_tree_block(struct btrfs_root *root, u64 bytenr)
         if (IS_ERR(buf))
                 return;
         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
-                                 buf, 0, WAIT_NONE, btree_get_extent, 0);
+                                 buf, WAIT_NONE, btree_get_extent, 0);
         free_extent_buffer(buf);
 }
 
@@ -1150,7 +1149,7 @@ int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
 
         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
 
-        ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
+        ret = read_extent_buffer_pages(io_tree, buf, WAIT_PAGE_LOCK,
                                        btree_get_extent, mirror_num);
         if (ret) {
                 free_extent_buffer(buf);
@@ -1206,7 +1205,7 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
         if (IS_ERR(buf))
                 return buf;
 
-        ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
+        ret = btree_read_extent_buffer_pages(root, buf, parent_transid);
         if (ret) {
                 free_extent_buffer(buf);
                 return ERR_PTR(ret);
@@ -4081,7 +4080,7 @@ void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root)
 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
 {
         struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
-        return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
+        return btree_read_extent_buffer_pages(root, buf, parent_transid);
 }
 
 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 14ab8576cc93..c046addd9917 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5188,11 +5188,10 @@ int extent_buffer_uptodate(struct extent_buffer *eb)
 }
 
 int read_extent_buffer_pages(struct extent_io_tree *tree,
-                             struct extent_buffer *eb, u64 start, int wait,
+                             struct extent_buffer *eb, int wait,
                              get_extent_t *get_extent, int mirror_num)
 {
         unsigned long i;
-        unsigned long start_i;
         struct page *page;
         int err;
         int ret = 0;
@@ -5206,16 +5205,8 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
                 return 0;
 
-        if (start) {
-                WARN_ON(start < eb->start);
-                start_i = (start >> PAGE_SHIFT) -
-                        (eb->start >> PAGE_SHIFT);
-        } else {
-                start_i = 0;
-        }
-
         num_pages = num_extent_pages(eb->start, eb->len);
-        for (i = start_i; i < num_pages; i++) {
+        for (i = 0; i < num_pages; i++) {
                 page = eb->pages[i];
                 if (wait == WAIT_NONE) {
                         if (!trylock_page(page))
@@ -5230,7 +5221,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
          * the uptodate bit of our pages won't be affected by
          * clear_extent_buffer_uptodate().
          */
-        for (i = start_i; i < num_pages; i++) {
+        for (i = 0; i < num_pages; i++) {
                 page = eb->pages[i];
                 if (!PageUptodate(page)) {
                         num_reads++;
@@ -5239,15 +5230,14 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         }
 
         if (all_uptodate) {
-                if (start_i == 0)
-                        set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+                set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
                 goto unlock_exit;
         }
 
         clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
         eb->read_mirror = 0;
         atomic_set(&eb->io_pages, num_reads);
-        for (i = start_i; i < num_pages; i++) {
+        for (i = 0; i < num_pages; i++) {
                 page = eb->pages[i];
 
                 if (!PageUptodate(page)) {
@@ -5288,7 +5278,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         if (ret || wait != WAIT_COMPLETE)
                 return ret;
 
-        for (i = start_i; i < num_pages; i++) {
+        for (i = 0; i < num_pages; i++) {
                 page = eb->pages[i];
                 wait_on_page_locked(page);
                 if (!PageUptodate(page))
@@ -5298,12 +5288,10 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         return ret;
 
 unlock_exit:
-        i = start_i;
         while (locked_pages > 0) {
-                page = eb->pages[i];
-                i++;
-                unlock_page(page);
                 locked_pages--;
+                page = eb->pages[locked_pages];
+                unlock_page(page);
         }
         return ret;
 }
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 60536f3bf434..4a094f1dc7ef 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -359,7 +359,7 @@ void free_extent_buffer_stale(struct extent_buffer *eb);
 #define WAIT_COMPLETE   1
 #define WAIT_PAGE_LOCK  2
 int read_extent_buffer_pages(struct extent_io_tree *tree,
-                             struct extent_buffer *eb, u64 start, int wait,
+                             struct extent_buffer *eb, int wait,
                              get_extent_t *get_extent, int mirror_num);
 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);