Btrfs: fallocate: Work with sectorsized blocks
authorChandan Rajendra <chandan@linux.vnet.ibm.com>
Thu, 21 Jan 2016 10:25:56 +0000 (15:55 +0530)
committerDavid Sterba <dsterba@suse.com>
Mon, 1 Feb 2016 18:24:29 +0000 (19:24 +0100)
While at it, this commit changes btrfs_truncate_page() to truncate sectorsized
blocks instead of pages. Hence the function has been renamed to
btrfs_truncate_block().

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
fs/btrfs/ctree.h
fs/btrfs/file.c
fs/btrfs/inode.c

index ffb3617..42ab582 100644 (file)
@@ -4030,7 +4030,7 @@ int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root,
                        struct inode *dir, u64 objectid,
                        const char *name, int name_len);
-int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
+int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
                        int front);
 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
index 9809557..58bb297 100644 (file)
@@ -2310,10 +2310,10 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
        int ret = 0;
        int err = 0;
        unsigned int rsv_count;
-       bool same_page;
+       bool same_block;
        bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
        u64 ino_size;
-       bool truncated_page = false;
+       bool truncated_block = false;
        bool updated_inode = false;
 
        ret = btrfs_wait_ordered_range(inode, offset, len);
@@ -2321,7 +2321,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
                return ret;
 
        mutex_lock(&inode->i_mutex);
-       ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
+       ino_size = round_up(inode->i_size, root->sectorsize);
        ret = find_first_non_hole(inode, &offset, &len);
        if (ret < 0)
                goto out_only_mutex;
@@ -2334,31 +2334,30 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
        lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
        lockend = round_down(offset + len,
                             BTRFS_I(inode)->root->sectorsize) - 1;
-       same_page = ((offset >> PAGE_CACHE_SHIFT) ==
-                   ((offset + len - 1) >> PAGE_CACHE_SHIFT));
-
+       same_block = (BTRFS_BYTES_TO_BLKS(root->fs_info, offset))
+               == (BTRFS_BYTES_TO_BLKS(root->fs_info, offset + len - 1));
        /*
-        * We needn't truncate any page which is beyond the end of the file
+        * We needn't truncate any block which is beyond the end of the file
         * because we are sure there is no data there.
         */
        /*
-        * Only do this if we are in the same page and we aren't doing the
-        * entire page.
+        * Only do this if we are in the same block and we aren't doing the
+        * entire block.
         */
-       if (same_page && len < PAGE_CACHE_SIZE) {
+       if (same_block && len < root->sectorsize) {
                if (offset < ino_size) {
-                       truncated_page = true;
-                       ret = btrfs_truncate_page(inode, offset, len, 0);
+                       truncated_block = true;
+                       ret = btrfs_truncate_block(inode, offset, len, 0);
                } else {
                        ret = 0;
                }
                goto out_only_mutex;
        }
 
-       /* zero back part of the first page */
+       /* zero back part of the first block */
        if (offset < ino_size) {
-               truncated_page = true;
-               ret = btrfs_truncate_page(inode, offset, 0, 0);
+               truncated_block = true;
+               ret = btrfs_truncate_block(inode, offset, 0, 0);
                if (ret) {
                        mutex_unlock(&inode->i_mutex);
                        return ret;
@@ -2393,9 +2392,10 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
                if (!ret) {
                        /* zero the front end of the last page */
                        if (tail_start + tail_len < ino_size) {
-                               truncated_page = true;
-                               ret = btrfs_truncate_page(inode,
-                                               tail_start + tail_len, 0, 1);
+                               truncated_block = true;
+                               ret = btrfs_truncate_block(inode,
+                                                       tail_start + tail_len,
+                                                       0, 1);
                                if (ret)
                                        goto out_only_mutex;
                        }
@@ -2575,7 +2575,7 @@ out:
        unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
                             &cached_state, GFP_NOFS);
 out_only_mutex:
-       if (!updated_inode && truncated_page && !ret && !err) {
+       if (!updated_inode && truncated_block && !ret && !err) {
                /*
                 * If we only end up zeroing part of a page, we still need to
                 * update the inode item, so that all the time fields are
@@ -2695,10 +2695,10 @@ static long btrfs_fallocate(struct file *file, int mode,
        } else if (offset + len > inode->i_size) {
                /*
                 * If we are fallocating from the end of the file onward we
-                * need to zero out the end of the page if i_size lands in the
-                * middle of a page.
+                * need to zero out the end of the block if i_size lands in the
+                * middle of a block.
                 */
-               ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
+               ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
                if (ret)
                        goto out;
        }
index 53c9dd1..0bfd7fb 100644 (file)
@@ -4247,7 +4247,8 @@ static int truncate_inline_extent(struct inode *inode,
                 * read the extent item from disk (data not in the page cache).
                 */
                btrfs_release_path(path);
-               return btrfs_truncate_page(inode, offset, page_end - offset, 0);
+               return btrfs_truncate_block(inode, offset, page_end - offset,
+                                       0);
        }
 
        btrfs_set_file_extent_ram_bytes(leaf, fi, size);
@@ -4600,17 +4601,17 @@ error:
 }
 
 /*
- * btrfs_truncate_page - read, zero a chunk and write a page
+ * btrfs_truncate_block - read, zero a chunk and write a block
  * @inode - inode that we're zeroing
  * @from - the offset to start zeroing
  * @len - the length to zero, 0 to zero the entire range respective to the
  *     offset
  * @front - zero up to the offset instead of from the offset on
  *
- * This will find the page for the "from" offset and cow the page and zero the
+ * This will find the block for the "from" offset and cow the block and zero the
  * part we want to zero.  This is used with truncate and hole punching.
  */
-int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
+int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
                        int front)
 {
        struct address_space *mapping = inode->i_mapping;
@@ -4621,18 +4622,19 @@ int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
        char *kaddr;
        u32 blocksize = root->sectorsize;
        pgoff_t index = from >> PAGE_CACHE_SHIFT;
-       unsigned offset = from & (PAGE_CACHE_SIZE-1);
+       unsigned offset = from & (blocksize - 1);
        struct page *page;
        gfp_t mask = btrfs_alloc_write_mask(mapping);
        int ret = 0;
-       u64 page_start;
-       u64 page_end;
+       u64 block_start;
+       u64 block_end;
 
        if ((offset & (blocksize - 1)) == 0 &&
            (!len || ((len & (blocksize - 1)) == 0)))
                goto out;
+
        ret = btrfs_delalloc_reserve_space(inode,
-                       round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
+                       round_down(from, blocksize), blocksize);
        if (ret)
                goto out;
 
@@ -4640,14 +4642,14 @@ again:
        page = find_or_create_page(mapping, index, mask);
        if (!page) {
                btrfs_delalloc_release_space(inode,
-                               round_down(from, PAGE_CACHE_SIZE),
-                               PAGE_CACHE_SIZE);
+                               round_down(from, blocksize),
+                               blocksize);
                ret = -ENOMEM;
                goto out;
        }
 
-       page_start = page_offset(page);
-       page_end = page_start + PAGE_CACHE_SIZE - 1;
+       block_start = round_down(from, blocksize);
+       block_end = block_start + blocksize - 1;
 
        if (!PageUptodate(page)) {
                ret = btrfs_readpage(NULL, page);
@@ -4664,12 +4666,12 @@ again:
        }
        wait_on_page_writeback(page);
 
-       lock_extent_bits(io_tree, page_start, page_end, &cached_state);
+       lock_extent_bits(io_tree, block_start, block_end, &cached_state);
        set_page_extent_mapped(page);
 
-       ordered = btrfs_lookup_ordered_extent(inode, page_start);
+       ordered = btrfs_lookup_ordered_extent(inode, block_start);
        if (ordered) {
-               unlock_extent_cached(io_tree, page_start, page_end,
+               unlock_extent_cached(io_tree, block_start, block_end,
                                     &cached_state, GFP_NOFS);
                unlock_page(page);
                page_cache_release(page);
@@ -4678,39 +4680,41 @@ again:
                goto again;
        }
 
-       clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
+       clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
                          EXTENT_DIRTY | EXTENT_DELALLOC |
                          EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
                          0, 0, &cached_state, GFP_NOFS);
 
-       ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
+       ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
                                        &cached_state);
        if (ret) {
-               unlock_extent_cached(io_tree, page_start, page_end,
+               unlock_extent_cached(io_tree, block_start, block_end,
                                     &cached_state, GFP_NOFS);
                goto out_unlock;
        }
 
-       if (offset != PAGE_CACHE_SIZE) {
+       if (offset != blocksize) {
                if (!len)
-                       len = PAGE_CACHE_SIZE - offset;
+                       len = blocksize - offset;
                kaddr = kmap(page);
                if (front)
-                       memset(kaddr, 0, offset);
+                       memset(kaddr + (block_start - page_offset(page)),
+                               0, offset);
                else
-                       memset(kaddr + offset, 0, len);
+                       memset(kaddr + (block_start - page_offset(page)) +  offset,
+                               0, len);
                flush_dcache_page(page);
                kunmap(page);
        }
        ClearPageChecked(page);
        set_page_dirty(page);
-       unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
+       unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
                             GFP_NOFS);
 
 out_unlock:
        if (ret)
-               btrfs_delalloc_release_space(inode, page_start,
-                                            PAGE_CACHE_SIZE);
+               btrfs_delalloc_release_space(inode, block_start,
+                                            blocksize);
        unlock_page(page);
        page_cache_release(page);
 out:
@@ -4781,11 +4785,11 @@ int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
        int err = 0;
 
        /*
-        * If our size started in the middle of a page we need to zero out the
-        * rest of the page before we expand the i_size, otherwise we could
+        * If our size started in the middle of a block we need to zero out the
+        * rest of the block before we expand the i_size, otherwise we could
         * expose stale data.
         */
-       err = btrfs_truncate_page(inode, oldsize, 0, 0);
+       err = btrfs_truncate_block(inode, oldsize, 0, 0);
        if (err)
                return err;