@@ -919,6 +919,15 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
cache = container_of(object->fscache.cache,
struct cachefiles_cache, cache);
+ pos = (loff_t)page->index << PAGE_SHIFT;
+
+ /* We mustn't write more data than we have, so we have to beware of a
+ * partial page at EOF.
+ */
+ eof = object->fscache.store_limit_l;
+ if (pos >= eof)
+ goto error;
+
/* write the page to the backing filesystem and let it store it in its
* own time */
path.mnt = cache->mnt;
@@ -926,49 +935,43 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page)
file = dentry_open(&path, O_RDWR | O_LARGEFILE, cache->cache_cred);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
- } else {
- ret = -EIO;
- if (file->f_op->write) {
- pos = (loff_t) page->index << PAGE_SHIFT;
-
- /* we mustn't write more data than we have, so we have
- * to beware of a partial page at EOF */
- eof = object->fscache.store_limit_l;
- len = PAGE_SIZE;
- if (eof & ~PAGE_MASK) {
- ASSERTCMP(pos, <, eof);
- if (eof - pos < PAGE_SIZE) {
- _debug("cut short %llx to %llx",
- pos, eof);
- len = eof - pos;
- ASSERTCMP(pos + len, ==, eof);
- }
- }
+ goto error_2;
+ }
- data = kmap(page);
- file_start_write(file);
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- ret = file->f_op->write(
- file, (const void __user *) data, len, &pos);
- set_fs(old_fs);
- kunmap(page);
- file_end_write(file);
- if (ret != len)
- ret = -EIO;
+ len = PAGE_SIZE;
+ if (eof & ~PAGE_MASK) {
+ if (eof - pos < PAGE_SIZE) {
+ _debug("cut short %llx to %llx",
+ pos, eof);
+ len = eof - pos;
+ ASSERTCMP(pos + len, ==, eof);
}
- fput(file);
}
- if (ret < 0) {
- if (ret == -EIO)
- cachefiles_io_error_obj(
- object, "Write page to backing file failed");
- ret = -ENOBUFS;
- }
+ data = kmap(page);
+ file_start_write(file);
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = file->f_op->write(
+ file, (const void __user *) data, len, &pos);
+ set_fs(old_fs);
+ kunmap(page);
+ fput(file);
+ if (ret != len)
+ goto error_eio;
+
+ _leave(" = 0");
+ return 0;
- _leave(" = %d", ret);
- return ret;
+error_eio:
+ ret = -EIO;
+error_2:
+ if (ret == -EIO)
+ cachefiles_io_error_obj(object,
+ "Write page to backing file failed");
+error:
+ _leave(" = -ENOBUFS [%d]", ret);
+ return -ENOBUFS;
}
/*
@@ -801,7 +801,7 @@ static void fscache_write_op(struct fscache_operation *_op)
goto superseded;
page = results[0];
_debug("gang %d [%lx]", n, page->index);
- if (page->index > op->store_limit) {
+ if (page->index >= op->store_limit) {
fscache_stat(&fscache_n_store_pages_over_limit);
goto superseded;
}