jffs2: convert to new aops
Nick Piggin [Tue, 16 Oct 2007 08:25:18 +0000 (01:25 -0700)]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/jffs2/file.c

index c253019..023a175 100644 (file)
 #include <linux/jffs2.h>
 #include "nodelist.h"
 
-static int jffs2_commit_write (struct file *filp, struct page *pg,
-                              unsigned start, unsigned end);
-static int jffs2_prepare_write (struct file *filp, struct page *pg,
-                               unsigned start, unsigned end);
+static int jffs2_write_end(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned copied,
+                       struct page *pg, void *fsdata);
+static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned flags,
+                       struct page **pagep, void **fsdata);
 static int jffs2_readpage (struct file *filp, struct page *pg);
 
 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
@@ -65,8 +67,8 @@ const struct inode_operations jffs2_file_inode_operations =
 const struct address_space_operations jffs2_file_address_operations =
 {
        .readpage =     jffs2_readpage,
-       .prepare_write =jffs2_prepare_write,
-       .commit_write = jffs2_commit_write
+       .write_begin =  jffs2_write_begin,
+       .write_end =    jffs2_write_end,
 };
 
 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
@@ -119,15 +121,23 @@ static int jffs2_readpage (struct file *filp, struct page *pg)
        return ret;
 }
 
-static int jffs2_prepare_write (struct file *filp, struct page *pg,
-                               unsigned start, unsigned end)
+static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned flags,
+                       struct page **pagep, void **fsdata)
 {
-       struct inode *inode = pg->mapping->host;
+       struct page *pg;
+       struct inode *inode = mapping->host;
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
-       uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
+       pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+       uint32_t pageofs = pos & (PAGE_CACHE_SIZE - 1);
        int ret = 0;
 
-       D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
+       pg = __grab_cache_page(mapping, index);
+       if (!pg)
+               return -ENOMEM;
+       *pagep = pg;
+
+       D1(printk(KERN_DEBUG "jffs2_write_begin()\n"));
 
        if (pageofs > inode->i_size) {
                /* Make new hole frag from old EOF to new page */
@@ -142,7 +152,7 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
                ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
                                          ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
                if (ret)
-                       return ret;
+                       goto out_page;
 
                down(&f->sem);
                memset(&ri, 0, sizeof(ri));
@@ -172,7 +182,7 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
                        ret = PTR_ERR(fn);
                        jffs2_complete_reservation(c);
                        up(&f->sem);
-                       return ret;
+                       goto out_page;
                }
                ret = jffs2_add_full_dnode_to_inode(c, f, fn);
                if (f->metadata) {
@@ -181,65 +191,79 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
                        f->metadata = NULL;
                }
                if (ret) {
-                       D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
+                       D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", ret));
                        jffs2_mark_node_obsolete(c, fn->raw);
                        jffs2_free_full_dnode(fn);
                        jffs2_complete_reservation(c);
                        up(&f->sem);
-                       return ret;
+                       goto out_page;
                }
                jffs2_complete_reservation(c);
                inode->i_size = pageofs;
                up(&f->sem);
        }
 
-       /* Read in the page if it wasn't already present, unless it's a whole page */
-       if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
+       /*
+        * Read in the page if it wasn't already present. Cannot optimize away
+        * the whole page write case until jffs2_write_end can handle the
+        * case of a short-copy.
+        */
+       if (!PageUptodate(pg)) {
                down(&f->sem);
                ret = jffs2_do_readpage_nolock(inode, pg);
                up(&f->sem);
+               if (ret)
+                       goto out_page;
        }
-       D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
+       D1(printk(KERN_DEBUG "end write_begin(). pg->flags %lx\n", pg->flags));
+       return ret;
+
+out_page:
+       unlock_page(pg);
+       page_cache_release(pg);
        return ret;
 }
 
-static int jffs2_commit_write (struct file *filp, struct page *pg,
-                              unsigned start, unsigned end)
+static int jffs2_write_end(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned copied,
+                       struct page *pg, void *fsdata)
 {
        /* Actually commit the write from the page cache page we're looking at.
         * For now, we write the full page out each time. It sucks, but it's simple
         */
-       struct inode *inode = pg->mapping->host;
+       struct inode *inode = mapping->host;
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
        struct jffs2_raw_inode *ri;
+       unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+       unsigned end = start + copied;
        unsigned aligned_start = start & ~3;
        int ret = 0;
        uint32_t writtenlen = 0;
 
-       D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
+       D1(printk(KERN_DEBUG "jffs2_write_end(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
                  inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
 
+       /* We need to avoid deadlock with page_cache_read() in
+          jffs2_garbage_collect_pass(). So the page must be
+          up to date to prevent page_cache_read() from trying
+          to re-lock it. */
+       BUG_ON(!PageUptodate(pg));
+
        if (end == PAGE_CACHE_SIZE) {
-               if (!start) {
-                       /* We need to avoid deadlock with page_cache_read() in
-                          jffs2_garbage_collect_pass(). So we have to mark the
-                          page up to date, to prevent page_cache_read() from
-                          trying to re-lock it. */
-                       SetPageUptodate(pg);
-               } else {
-                       /* When writing out the end of a page, write out the 
-                          _whole_ page. This helps to reduce the number of
-                          nodes in files which have many short writes, like
-                          syslog files. */
-                       start = aligned_start = 0;
-               }
+               /* When writing out the end of a page, write out the
+                  _whole_ page. This helps to reduce the number of
+                  nodes in files which have many short writes, like
+                  syslog files. */
+               start = aligned_start = 0;
        }
 
        ri = jffs2_alloc_raw_inode();
 
        if (!ri) {
-               D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
+               D1(printk(KERN_DEBUG "jffs2_write_end(): Allocation of raw inode failed\n"));
+               unlock_page(pg);
+               page_cache_release(pg);
                return -ENOMEM;
        }
 
@@ -287,11 +311,14 @@ static int jffs2_commit_write (struct file *filp, struct page *pg,
                /* generic_file_write has written more to the page cache than we've
                   actually written to the medium. Mark the page !Uptodate so that
                   it gets reread */
-               D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
+               D1(printk(KERN_DEBUG "jffs2_write_end(): Not all bytes written. Marking page !uptodate\n"));
                SetPageError(pg);
                ClearPageUptodate(pg);
        }
 
-       D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
-       return start+writtenlen==end?0:ret;
+       D1(printk(KERN_DEBUG "jffs2_write_end() returning %d\n",
+                                       writtenlen > 0 ? writtenlen : ret));
+       unlock_page(pg);
+       page_cache_release(pg);
+       return writtenlen > 0 ? writtenlen : ret;
 }