/*
* invalidate part or all of a page
*/
static void afs_file_invalidatepage(struct page *page, unsigned long offset)
{
int ret = 1;
_enter("{%lu},%lu", page->index, offset);
BUG_ON(!PageLocked(page));
if (PagePrivate(page)) {
#ifdef AFS_CACHING_SUPPORT
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
cachefs_uncache_page(vnode->cache,page);
#endif
/* We release buffers only if the entire page is being
* invalidated.
* The get_block cached value has been unconditionally
* invalidated, so real IO is not possible anymore.
*/
if (offset == 0) {
BUG_ON(!PageLocked(page));
ret = 0;
if (!PageWriteback(page))
ret = page->mapping->a_ops->releasepage(page,
0);
/* possibly should BUG_ON(!ret); - neilb */
}
}
_leave(" = %d", ret);
} /* end afs_file_invalidatepage() */
/*
* release a page and cleanup its private data
*/
static int afs_file_releasepage(struct page *page, gfp_t gfp_flags)
{
struct cachefs_page *pageio;
_enter("{%lu},%x", page->index, gfp_flags);
if (PagePrivate(page)) {
#ifdef AFS_CACHING_SUPPORT
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
cachefs_uncache_page(vnode->cache, page);
#endif
pageio = (struct cachefs_page *) page_private(page);
set_page_private(page, 0);
ClearPagePrivate(page);
kfree(pageio);
}
_leave(" = 0");
return 0;
} /* end afs_file_releasepage() */
/*
* AFS read page from file (or symlink)
*/
static int afs_file_readpage(struct file *file, struct page *page)
{
struct afs_rxfs_fetch_descriptor desc;
#ifdef AFS_CACHING_SUPPORT
struct cachefs_page *pageio;
#endif
struct afs_vnode *vnode;
struct inode *inode;
int ret;
inode = page->mapping->host;
_enter("{%lu},{%lu}", inode->i_ino, page->index);
vnode = AFS_FS_I(inode);
BUG_ON(!PageLocked(page));
ret = -ESTALE;
if (vnode->flags & AFS_VNODE_DELETED)
goto error;
#ifdef AFS_CACHING_SUPPORT
ret = cachefs_page_get_private(page, &pageio, GFP_NOIO);
if (ret < 0)
goto error;
/* is it cached? */
ret = cachefs_read_or_alloc_page(vnode->cache,
page,
afs_file_readpage_read_complete,
NULL,
GFP_KERNEL);
#else
ret = -ENOBUFS;
#endif
switch (ret) {
/* read BIO submitted and wb-journal entry found */
case 1:
BUG(); // TODO - handle wb-journal match
/* read BIO submitted (page in cache) */
case 0:
break;
/* no page available in cache */
case -ENOBUFS:
case -ENODATA:
default:
desc.fid = vnode->fid;
desc.offset = page->index << PAGE_CACHE_SHIFT;
desc.size = min((size_t) (inode->i_size - desc.offset),
(size_t) PAGE_SIZE);
desc.buffer = kmap(page);
clear_page(desc.buffer);
/* read the contents of the file from the server into the
* page */
ret = afs_vnode_fetch_data(vnode, &desc);
kunmap(page);
if (ret < 0) {
if (ret==-ENOENT) {
_debug("got NOENT from server"
" - marking file deleted and stale");
vnode->flags |= AFS_VNODE_DELETED;
ret = -ESTALE;
}
#ifdef AFS_CACHING_SUPPORT
cachefs_uncache_page(vnode->cache, page);
#endif
goto error;
}
SetPageUptodate(page);
#ifdef AFS_CACHING_SUPPORT
if (cachefs_write_page(vnode->cache,
page,
afs_file_readpage_write_complete,
NULL,
GFP_KERNEL) != 0
) {
cachefs_uncache_page(vnode->cache, page);
unlock_page(page);
}
#else
unlock_page(page);
#endif
}
_leave(" = 0");
return 0;
error:
SetPageError(page);
unlock_page(page);
_leave(" = %d", ret);
return ret;
} /* end afs_file_readpage() */
/*
* AFS read page from file, directory or symlink
*/
static int afs_readpage(struct file *file, struct page *page)
{
struct afs_vnode *vnode;
struct inode *inode;
struct key *key;
size_t len;
off_t offset;
int ret;
inode = page->mapping->host;
ASSERT(file != NULL);
key = file->private_data;
ASSERT(key != NULL);
_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
vnode = AFS_FS_I(inode);
BUG_ON(!PageLocked(page));
ret = -ESTALE;
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
goto error;
#ifdef AFS_CACHING_SUPPORT
/* is it cached? */
ret = cachefs_read_or_alloc_page(vnode->cache,
page,
afs_file_readpage_read_complete,
NULL,
GFP_KERNEL);
#else
ret = -ENOBUFS;
#endif
switch (ret) {
/* read BIO submitted and wb-journal entry found */
case 1:
BUG(); // TODO - handle wb-journal match
/* read BIO submitted (page in cache) */
case 0:
break;
/* no page available in cache */
case -ENOBUFS:
case -ENODATA:
default:
offset = page->index << PAGE_CACHE_SHIFT;
len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
/* read the contents of the file from the server into the
* page */
ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
if (ret < 0) {
if (ret == -ENOENT) {
_debug("got NOENT from server"
" - marking file deleted and stale");
set_bit(AFS_VNODE_DELETED, &vnode->flags);
ret = -ESTALE;
}
#ifdef AFS_CACHING_SUPPORT
cachefs_uncache_page(vnode->cache, page);
#endif
goto error;
}
SetPageUptodate(page);
#ifdef AFS_CACHING_SUPPORT
if (cachefs_write_page(vnode->cache,
page,
afs_file_readpage_write_complete,
NULL,
GFP_KERNEL) != 0
) {
cachefs_uncache_page(vnode->cache, page);
unlock_page(page);
}
#else
unlock_page(page);
#endif
}
_leave(" = 0");
return 0;
error:
SetPageError(page);
unlock_page(page);
_leave(" = %d", ret);
return ret;
}