1 files changed, 66 insertions, 39 deletions

diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index c2530197be0c..023a17539dd4 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -19,10 +19,12 @@
 #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;
 }