gfs2: convert to new aops

Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 127 insertions, 84 deletions

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 873a511ef2be..9679f8b9870d 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -17,6 +17,7 @@
 #include <linux/mpage.h>
 #include <linux/fs.h>
 #include <linux/writeback.h>
+#include <linux/swap.h>
 #include <linux/gfs2_ondisk.h>
 #include <linux/lm_interface.h>
 
@@ -349,45 +350,49 @@ out_unlock:
 }
 
 /**
- * gfs2_prepare_write - Prepare to write a page to a file
+ * gfs2_write_begin - Begin to write to a file
  * @file: The file to write to
- * @page: The page which is to be prepared for writing
- * @from: From (byte range within page)
- * @to: To (byte range within page)
+ * @mapping: The mapping in which to write
+ * @pos: The file offset at which to start writing
+ * @len: Length of the write
+ * @flags: Various flags
+ * @pagep: Pointer to return the page
+ * @fsdata: Pointer to return fs data (unused by GFS2)
  *
  * Returns: errno
  */
 
-static int gfs2_prepare_write(struct file *file, struct page *page,
-                              unsigned from, unsigned to)
+static int gfs2_write_begin(struct file *file, struct address_space *mapping,
+                            loff_t pos, unsigned len, unsigned flags,
+                            struct page **pagep, void **fsdata)
 {
-        struct gfs2_inode *ip = GFS2_I(page->mapping->host);
-        struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+        struct gfs2_inode *ip = GFS2_I(mapping->host);
+        struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
         unsigned int data_blocks, ind_blocks, rblocks;
         int alloc_required;
         int error = 0;
-        loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
-        loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
         struct gfs2_alloc *al;
-        unsigned int write_len = to - from;
+        pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+        unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+        unsigned to = from + len;
+        struct page *page;
 
-
-        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|LM_FLAG_TRY_1CB, &ip->i_gh);
+        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh);
         error = gfs2_glock_nq_atime(&ip->i_gh);
-        if (unlikely(error)) {
-                if (error == GLR_TRYFAILED) {
-                        unlock_page(page);
-                        error = AOP_TRUNCATED_PAGE;
-                        yield();
-                }
+        if (unlikely(error))
                 goto out_uninit;
-        }
 
-        gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks);
+        error = -ENOMEM;
+        page = __grab_cache_page(mapping, index);
+        *pagep = page;
+        if (!page)
+                goto out_unlock;
+
+        gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
 
-        error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required);
+        error = gfs2_write_alloc_required(ip, pos, len, &alloc_required);
         if (error)
-                goto out_unlock;
+                goto out_putpage;
 
 
         ip->i_alloc.al_requested = 0;
@@ -420,7 +425,7 @@ static int gfs2_prepare_write(struct file *file, struct page *page,
                 goto out_trans_fail;
 
         if (gfs2_is_stuffed(ip)) {
-                if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
+                if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
                         error = gfs2_unstuff_dinode(ip, page);
                         if (error == 0)
                                 goto prepare_write;
@@ -443,6 +448,10 @@ out_qunlock:
 out_alloc_put:
                         gfs2_alloc_put(ip);
                 }
+out_putpage:
+                page_cache_release(page);
+                if (pos + len > ip->i_inode.i_size)
+                        vmtruncate(&ip->i_inode, ip->i_inode.i_size);
 out_unlock:
                 gfs2_glock_dq_m(1, &ip->i_gh);
 out_uninit:
@@ -478,65 +487,117 @@ static void adjust_fs_space(struct inode *inode)
 }
 
 /**
- * gfs2_commit_write - Commit write to a file
+ * gfs2_stuffed_write_end - Write end for stuffed files
+ * @inode: The inode
+ * @dibh: The buffer_head containing the on-disk inode
+ * @pos: The file position
+ * @len: The length of the write
+ * @copied: How much was actually copied by the VFS
+ * @page: The page
+ *
+ * This copies the data from the page into the inode block after
+ * the inode data structure itself.
+ *
+ * Returns: errno
+ */
+static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
+                                  loff_t pos, unsigned len, unsigned copied,
+                                  struct page *page)
+{
+        struct gfs2_inode *ip = GFS2_I(inode);
+        struct gfs2_sbd *sdp = GFS2_SB(inode);
+        u64 to = pos + copied;
+        void *kaddr;
+        unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
+        struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
+
+        BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
+        kaddr = kmap_atomic(page, KM_USER0);
+        memcpy(buf + pos, kaddr + pos, copied);
+        memset(kaddr + pos + copied, 0, len - copied);
+        flush_dcache_page(page);
+        kunmap_atomic(kaddr, KM_USER0);
+
+        if (!PageUptodate(page))
+                SetPageUptodate(page);
+        unlock_page(page);
+        page_cache_release(page);
+
+        if (inode->i_size < to) {
+                i_size_write(inode, to);
+                ip->i_di.di_size = inode->i_size;
+                di->di_size = cpu_to_be64(inode->i_size);
+                mark_inode_dirty(inode);
+        }
+
+        if (inode == sdp->sd_rindex)
+                adjust_fs_space(inode);
+
+        brelse(dibh);
+        gfs2_trans_end(sdp);
+        gfs2_glock_dq(&ip->i_gh);
+        gfs2_holder_uninit(&ip->i_gh);
+        return copied;
+}
+
+/**
+ * gfs2_write_end
  * @file: The file to write to
- * @page: The page containing the data
- * @from: From (byte range within page)
- * @to: To (byte range within page)
+ * @mapping: The address space to write to
+ * @pos: The file position
+ * @len: The length of the data
+ * @copied:
+ * @page: The page that has been written
+ * @fsdata: The fsdata (unused in GFS2)
+ *
+ * The main write_end function for GFS2. We have a separate one for
+ * stuffed files as they are slightly different, otherwise we just
+ * put our locking around the VFS provided functions.
  *
  * Returns: errno
  */
 
-static int gfs2_commit_write(struct file *file, struct page *page,
-                             unsigned from, unsigned to)
+static int gfs2_write_end(struct file *file, struct address_space *mapping,
+                          loff_t pos, unsigned len, unsigned copied,
+                          struct page *page, void *fsdata)
 {
         struct inode *inode = page->mapping->host;
         struct gfs2_inode *ip = GFS2_I(inode);
         struct gfs2_sbd *sdp = GFS2_SB(inode);
-        int error = -EOPNOTSUPP;
         struct buffer_head *dibh;
         struct gfs2_alloc *al = &ip->i_alloc;
         struct gfs2_dinode *di;
+        unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
+        unsigned int to = from + len;
+        int ret;
 
-        if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
-                goto fail_nounlock;
+        BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == 0);
 
-        error = gfs2_meta_inode_buffer(ip, &dibh);
-        if (error)
-                goto fail_endtrans;
+        ret = gfs2_meta_inode_buffer(ip, &dibh);
+        if (unlikely(ret)) {
+                unlock_page(page);
+                page_cache_release(page);
+                goto failed;
+        }
 
         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
-        di = (struct gfs2_dinode *)dibh->b_data;
-
-        if (gfs2_is_stuffed(ip)) {
-                u64 file_size;
-                void *kaddr;
 
-                file_size = ((u64)page->index << PAGE_CACHE_SHIFT) + to;
+        if (gfs2_is_stuffed(ip))
+                return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
 
-                kaddr = kmap_atomic(page, KM_USER0);
-                memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
-                       kaddr + from, to - from);
-                kunmap_atomic(kaddr, KM_USER0);
+        if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
+                gfs2_page_add_databufs(ip, page, from, to);
 
-                SetPageUptodate(page);
+        ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
 
-                if (inode->i_size < file_size) {
-                        i_size_write(inode, file_size);
+        if (likely(ret >= 0)) {
+                copied = ret;
+                if  ((pos + copied) > inode->i_size) {
+                        di = (struct gfs2_dinode *)dibh->b_data;
+                        ip->i_di.di_size = inode->i_size;
+                        di->di_size = cpu_to_be64(inode->i_size);
                         mark_inode_dirty(inode);
                 }
-        } else {
-                if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
-                    gfs2_is_jdata(ip))
-                        gfs2_page_add_databufs(ip, page, from, to);
-                error = generic_commit_write(file, page, from, to);
-                if (error)
-                        goto fail;
-        }
-
-        if (ip->i_di.di_size < inode->i_size) {
-                ip->i_di.di_size = inode->i_size;
-                di->di_size = cpu_to_be64(inode->i_size);
         }
 
         if (inode == sdp->sd_rindex)
@@ -544,33 +605,15 @@ static int gfs2_commit_write(struct file *file, struct page *page,
 
         brelse(dibh);
         gfs2_trans_end(sdp);
+failed:
         if (al->al_requested) {
                 gfs2_inplace_release(ip);
                 gfs2_quota_unlock(ip);
                 gfs2_alloc_put(ip);
         }
-        unlock_page(page);
-        gfs2_glock_dq_m(1, &ip->i_gh);
-        lock_page(page);
+        gfs2_glock_dq(&ip->i_gh);
         gfs2_holder_uninit(&ip->i_gh);
-        return 0;
-
-fail:
-        brelse(dibh);
-fail_endtrans:
-        gfs2_trans_end(sdp);
-        if (al->al_requested) {
-                gfs2_inplace_release(ip);
-                gfs2_quota_unlock(ip);
-                gfs2_alloc_put(ip);
-        }
-        unlock_page(page);
-        gfs2_glock_dq_m(1, &ip->i_gh);
-        lock_page(page);
-        gfs2_holder_uninit(&ip->i_gh);
-fail_nounlock:
-        ClearPageUptodate(page);
-        return error;
+        return ret;
 }
 
 /**
@@ -799,8 +842,8 @@ const struct address_space_operations gfs2_file_aops = {
         .readpage = gfs2_readpage,
         .readpages = gfs2_readpages,
         .sync_page = block_sync_page,
-        .prepare_write = gfs2_prepare_write,
-        .commit_write = gfs2_commit_write,
+        .write_begin = gfs2_write_begin,
+        .write_end = gfs2_write_end,
         .set_page_dirty = gfs2_set_page_dirty,
         .bmap = gfs2_bmap,
         .invalidatepage = gfs2_invalidatepage,