[Ocfs2-devel] [PATCH 02/15] ocfs2: Small refactor of truncate
zeroing code
Mark Fasheh
mark.fasheh at oracle.com
Fri Sep 7 14:20:45 PDT 2007
We'll want to reuse most of this when pushing inline data back out to an
extent. Keeping this part as a seperate patch helps to keep the upcoming
changes for write support uncluttered.
The core portion of ocfs2_zero_cluster_pages() responsible for making sure a
page is mapped and properly dirtied is abstracted out into it's own
function, ocfs2_map_and_dirty_page(). Actual functionality doesn't change,
though zeroing becomes optional.
We also turn part of ocfs2_free_write_ctxt() into a common function for
unlocking and freeing a page array. This operation is very common (and
uniform) for Ocfs2 cluster sizes greater than page size, so it makes sense
to keep the code in one place.
Signed-off-by: Mark Fasheh <mark.fasheh at oracle.com>
---
fs/ocfs2/alloc.c | 151 ++++++++++++++++++++++++++----------------------------
fs/ocfs2/aops.c | 20 ++++---
fs/ocfs2/aops.h | 2 +
3 files changed, 86 insertions(+), 87 deletions(-)
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 4f51766..46a0bc5 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -5664,12 +5664,50 @@ static int ocfs2_ordered_zero_func(handle_t *handle, struct buffer_head *bh)
return ocfs2_journal_dirty_data(handle, bh);
}
+static void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
+ unsigned int from, unsigned int to,
+ struct page *page, int zero, u64 *phys)
+{
+ int ret, partial = 0;
+
+ ret = ocfs2_map_page_blocks(page, phys, inode, from, to, 0);
+ if (ret)
+ mlog_errno(ret);
+
+ if (zero)
+ zero_user_page(page, from, to - from, KM_USER0);
+
+ /*
+ * Need to set the buffers we zero'd into uptodate
+ * here if they aren't - ocfs2_map_page_blocks()
+ * might've skipped some
+ */
+ if (ocfs2_should_order_data(inode)) {
+ ret = walk_page_buffers(handle,
+ page_buffers(page),
+ from, to, &partial,
+ ocfs2_ordered_zero_func);
+ if (ret < 0)
+ mlog_errno(ret);
+ } else {
+ ret = walk_page_buffers(handle, page_buffers(page),
+ from, to, &partial,
+ ocfs2_writeback_zero_func);
+ if (ret < 0)
+ mlog_errno(ret);
+ }
+
+ if (!partial)
+ SetPageUptodate(page);
+
+ flush_dcache_page(page);
+}
+
static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,
loff_t end, struct page **pages,
int numpages, u64 phys, handle_t *handle)
{
- int i, ret, partial = 0;
- void *kaddr;
+ int i;
struct page *page;
unsigned int from, to = PAGE_CACHE_SIZE;
struct super_block *sb = inode->i_sb;
@@ -5690,87 +5728,31 @@ static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,
BUG_ON(from > PAGE_CACHE_SIZE);
BUG_ON(to > PAGE_CACHE_SIZE);
- ret = ocfs2_map_page_blocks(page, &phys, inode, from, to, 0);
- if (ret)
- mlog_errno(ret);
-
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + from, 0, to - from);
- kunmap_atomic(kaddr, KM_USER0);
-
- /*
- * Need to set the buffers we zero'd into uptodate
- * here if they aren't - ocfs2_map_page_blocks()
- * might've skipped some
- */
- if (ocfs2_should_order_data(inode)) {
- ret = walk_page_buffers(handle,
- page_buffers(page),
- from, to, &partial,
- ocfs2_ordered_zero_func);
- if (ret < 0)
- mlog_errno(ret);
- } else {
- ret = walk_page_buffers(handle, page_buffers(page),
- from, to, &partial,
- ocfs2_writeback_zero_func);
- if (ret < 0)
- mlog_errno(ret);
- }
-
- if (!partial)
- SetPageUptodate(page);
-
- flush_dcache_page(page);
+ ocfs2_map_and_dirty_page(inode, handle, from, to, page, 1,
+ &phys);
start = (page->index + 1) << PAGE_CACHE_SHIFT;
}
out:
- if (pages) {
- for (i = 0; i < numpages; i++) {
- page = pages[i];
- unlock_page(page);
- mark_page_accessed(page);
- page_cache_release(page);
- }
- }
+ if (pages)
+ ocfs2_unlock_and_free_pages(pages, numpages);
}
static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,
- struct page **pages, int *num, u64 *phys)
+ struct page **pages, int *num)
{
- int i, numpages = 0, ret = 0;
- unsigned int ext_flags;
+ int numpages, ret = 0;
struct super_block *sb = inode->i_sb;
struct address_space *mapping = inode->i_mapping;
unsigned long index;
loff_t last_page_bytes;
- BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));
BUG_ON(start > end);
- if (start == end)
- goto out;
-
BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits !=
(end - 1) >> OCFS2_SB(sb)->s_clustersize_bits);
- ret = ocfs2_extent_map_get_blocks(inode, start >> sb->s_blocksize_bits,
- phys, NULL, &ext_flags);
- if (ret) {
- mlog_errno(ret);
- goto out;
- }
-
- /* Tail is a hole. */
- if (*phys == 0)
- goto out;
-
- /* Tail is marked as unwritten, we can count on write to zero
- * in that case. */
- if (ext_flags & OCFS2_EXT_UNWRITTEN)
- goto out;
-
+ numpages = 0;
last_page_bytes = PAGE_ALIGN(end);
index = start >> PAGE_CACHE_SHIFT;
do {
@@ -5787,14 +5769,8 @@ static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,
out:
if (ret != 0) {
- if (pages) {
- for (i = 0; i < numpages; i++) {
- if (pages[i]) {
- unlock_page(pages[i]);
- page_cache_release(pages[i]);
- }
- }
- }
+ if (pages)
+ ocfs2_unlock_and_free_pages(pages, numpages);
numpages = 0;
}
@@ -5815,18 +5791,20 @@ out:
int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
u64 range_start, u64 range_end)
{
- int ret, numpages;
+ int ret = 0, numpages;
struct page **pages = NULL;
u64 phys;
+ unsigned int ext_flags;
+ struct super_block *sb = inode->i_sb;
/*
* File systems which don't support sparse files zero on every
* extend.
*/
- if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
+ if (!ocfs2_sparse_alloc(OCFS2_SB(sb)))
return 0;
- pages = kcalloc(ocfs2_pages_per_cluster(inode->i_sb),
+ pages = kcalloc(ocfs2_pages_per_cluster(sb),
sizeof(struct page *), GFP_NOFS);
if (pages == NULL) {
ret = -ENOMEM;
@@ -5834,15 +5812,30 @@ int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
goto out;
}
- ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,
- &numpages, &phys);
+ if (range_start == range_end)
+ goto out;
+
+ ret = ocfs2_extent_map_get_blocks(inode,
+ range_start >> sb->s_blocksize_bits,
+ &phys, NULL, &ext_flags);
if (ret) {
mlog_errno(ret);
goto out;
}
- if (numpages == 0)
+ /*
+ * Tail is a hole, or is marked unwritten. In either case, we
+ * can count on read and write to return/push zero's.
+ */
+ if (phys == 0 || ext_flags & OCFS2_EXT_UNWRITTEN)
+ goto out;
+
+ ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,
+ &numpages);
+ if (ret) {
+ mlog_errno(ret);
goto out;
+ }
ocfs2_zero_cluster_pages(inode, range_start, range_end, pages,
numpages, phys, handle);
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 97394c5..57fc7e3 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -830,18 +830,22 @@ struct ocfs2_write_ctxt {
struct ocfs2_cached_dealloc_ctxt w_dealloc;
};
-static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
+void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
{
int i;
- for(i = 0; i < wc->w_num_pages; i++) {
- if (wc->w_pages[i] == NULL)
- continue;
-
- unlock_page(wc->w_pages[i]);
- mark_page_accessed(wc->w_pages[i]);
- page_cache_release(wc->w_pages[i]);
+ for(i = 0; i < num_pages; i++) {
+ if (pages[i]) {
+ unlock_page(pages[i]);
+ mark_page_accessed(pages[i]);
+ page_cache_release(pages[i]);
+ }
}
+}
+
+static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
+{
+ ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
brelse(wc->w_di_bh);
kfree(wc);
diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h
index 389579b..b4fa37d 100644
--- a/fs/ocfs2/aops.h
+++ b/fs/ocfs2/aops.h
@@ -34,6 +34,8 @@ int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
struct inode *inode, unsigned int from,
unsigned int to, int new);
+void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages);
+
int walk_page_buffers( handle_t *handle,
struct buffer_head *head,
unsigned from,
--
1.5.0.6
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