Btrfs: force a page fault if we have a shorty copy on a page boundary
[pandora-kernel.git] / fs / btrfs / file.c
index fa4ef18..e730510 100644 (file)
@@ -74,7 +74,7 @@ struct inode_defrag {
  * If an existing record is found the defrag item you
  * pass in is freed
  */
-static int __btrfs_add_inode_defrag(struct inode *inode,
+static void __btrfs_add_inode_defrag(struct inode *inode,
                                    struct inode_defrag *defrag)
 {
        struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -106,11 +106,11 @@ static int __btrfs_add_inode_defrag(struct inode *inode,
        BTRFS_I(inode)->in_defrag = 1;
        rb_link_node(&defrag->rb_node, parent, p);
        rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
-       return 0;
+       return;
 
 exists:
        kfree(defrag);
-       return 0;
+       return;
 
 }
 
@@ -123,7 +123,6 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
 {
        struct btrfs_root *root = BTRFS_I(inode)->root;
        struct inode_defrag *defrag;
-       int ret = 0;
        u64 transid;
 
        if (!btrfs_test_opt(root, AUTO_DEFRAG))
@@ -150,9 +149,11 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
 
        spin_lock(&root->fs_info->defrag_inodes_lock);
        if (!BTRFS_I(inode)->in_defrag)
-               ret = __btrfs_add_inode_defrag(inode, defrag);
+               __btrfs_add_inode_defrag(inode, defrag);
+       else
+               kfree(defrag);
        spin_unlock(&root->fs_info->defrag_inodes_lock);
-       return ret;
+       return 0;
 }
 
 /*
@@ -855,7 +856,8 @@ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
        btrfs_drop_extent_cache(inode, start, end - 1, 0);
 
        path = btrfs_alloc_path();
-       BUG_ON(!path);
+       if (!path)
+               return -ENOMEM;
 again:
        recow = 0;
        split = start;
@@ -1034,11 +1036,13 @@ out:
  * on error we return an unlocked page and the error value
  * on success we return a locked page and 0
  */
-static int prepare_uptodate_page(struct page *page, u64 pos)
+static int prepare_uptodate_page(struct page *page, u64 pos,
+                                bool force_uptodate)
 {
        int ret = 0;
 
-       if ((pos & (PAGE_CACHE_SIZE - 1)) && !PageUptodate(page)) {
+       if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
+           !PageUptodate(page)) {
                ret = btrfs_readpage(NULL, page);
                if (ret)
                        return ret;
@@ -1059,7 +1063,7 @@ static int prepare_uptodate_page(struct page *page, u64 pos)
 static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
                         struct page **pages, size_t num_pages,
                         loff_t pos, unsigned long first_index,
-                        unsigned long last_index, size_t write_bytes)
+                        size_t write_bytes, bool force_uptodate)
 {
        struct extent_state *cached_state = NULL;
        int i;
@@ -1073,15 +1077,10 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
        start_pos = pos & ~((u64)root->sectorsize - 1);
        last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
 
-       if (start_pos > inode->i_size) {
-               err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
-               if (err)
-                       return err;
-       }
-
 again:
        for (i = 0; i < num_pages; i++) {
-               pages[i] = grab_cache_page(inode->i_mapping, index + i);
+               pages[i] = find_or_create_page(inode->i_mapping, index + i,
+                                              GFP_NOFS);
                if (!pages[i]) {
                        faili = i - 1;
                        err = -ENOMEM;
@@ -1089,10 +1088,11 @@ again:
                }
 
                if (i == 0)
-                       err = prepare_uptodate_page(pages[i], pos);
+                       err = prepare_uptodate_page(pages[i], pos,
+                                                   force_uptodate);
                if (i == num_pages - 1)
                        err = prepare_uptodate_page(pages[i],
-                                                   pos + write_bytes);
+                                                   pos + write_bytes, false);
                if (err) {
                        page_cache_release(pages[i]);
                        faili = i - 1;
@@ -1158,10 +1158,10 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
        struct btrfs_root *root = BTRFS_I(inode)->root;
        struct page **pages = NULL;
        unsigned long first_index;
-       unsigned long last_index;
        size_t num_written = 0;
        int nrptrs;
        int ret = 0;
+       bool force_page_uptodate = false;
 
        nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
                     PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
@@ -1171,7 +1171,6 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                return -ENOMEM;
 
        first_index = pos >> PAGE_CACHE_SHIFT;
-       last_index = (pos + iov_iter_count(i)) >> PAGE_CACHE_SHIFT;
 
        while (iov_iter_count(i) > 0) {
                size_t offset = pos & (PAGE_CACHE_SIZE - 1);
@@ -1205,8 +1204,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                 * contents of pages from loop to loop
                 */
                ret = prepare_pages(root, file, pages, num_pages,
-                                   pos, first_index, last_index,
-                                   write_bytes);
+                                   pos, first_index, write_bytes,
+                                   force_page_uptodate);
                if (ret) {
                        btrfs_delalloc_release_space(inode,
                                        num_pages << PAGE_CACHE_SHIFT);
@@ -1223,12 +1222,15 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                if (copied < write_bytes)
                        nrptrs = 1;
 
-               if (copied == 0)
+               if (copied == 0) {
+                       force_page_uptodate = true;
                        dirty_pages = 0;
-               else
+               } else {
+                       force_page_uptodate = false;
                        dirty_pages = (copied + offset +
                                       PAGE_CACHE_SIZE - 1) >>
                                       PAGE_CACHE_SHIFT;
+               }
 
                /*
                 * If we had a short copy we need to release the excess delaloc
@@ -1238,9 +1240,11 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                 * managed to copy.
                 */
                if (num_pages > dirty_pages) {
-                       if (copied > 0)
-                               atomic_inc(
-                                       &BTRFS_I(inode)->outstanding_extents);
+                       if (copied > 0) {
+                               spin_lock(&BTRFS_I(inode)->lock);
+                               BTRFS_I(inode)->outstanding_extents++;
+                               spin_unlock(&BTRFS_I(inode)->lock);
+                       }
                        btrfs_delalloc_release_space(inode,
                                        (num_pages - dirty_pages) <<
                                        PAGE_CACHE_SHIFT);
@@ -1336,6 +1340,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
        struct inode *inode = fdentry(file)->d_inode;
        struct btrfs_root *root = BTRFS_I(inode)->root;
        loff_t *ppos = &iocb->ki_pos;
+       u64 start_pos;
        ssize_t num_written = 0;
        ssize_t err = 0;
        size_t count, ocount;
@@ -1384,6 +1389,15 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
        file_update_time(file);
        BTRFS_I(inode)->sequence++;
 
+       start_pos = round_down(pos, root->sectorsize);
+       if (start_pos > i_size_read(inode)) {
+               err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
+               if (err) {
+                       mutex_unlock(&inode->i_mutex);
+                       goto out;
+               }
+       }
+
        if (unlikely(file->f_flags & O_DIRECT)) {
                num_written = __btrfs_direct_write(iocb, iov, nr_segs,
                                                   pos, ppos, count, ocount);
@@ -1629,11 +1643,15 @@ static long btrfs_fallocate(struct file *file, int mode,
 
        cur_offset = alloc_start;
        while (1) {
+               u64 actual_end;
+
                em = btrfs_get_extent(inode, NULL, 0, cur_offset,
                                      alloc_end - cur_offset, 0);
                BUG_ON(IS_ERR_OR_NULL(em));
                last_byte = min(extent_map_end(em), alloc_end);
+               actual_end = min_t(u64, extent_map_end(em), offset + len);
                last_byte = (last_byte + mask) & ~mask;
+
                if (em->block_start == EXTENT_MAP_HOLE ||
                    (cur_offset >= inode->i_size &&
                     !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
@@ -1646,6 +1664,16 @@ static long btrfs_fallocate(struct file *file, int mode,
                                free_extent_map(em);
                                break;
                        }
+               } else if (actual_end > inode->i_size &&
+                          !(mode & FALLOC_FL_KEEP_SIZE)) {
+                       /*
+                        * We didn't need to allocate any more space, but we
+                        * still extended the size of the file so we need to
+                        * update i_size.
+                        */
+                       inode->i_ctime = CURRENT_TIME;
+                       i_size_write(inode, actual_end);
+                       btrfs_ordered_update_i_size(inode, actual_end, NULL);
                }
                free_extent_map(em);