/* file.c: AFS filesystem file handling * * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/buffer_head.h> #include "volume.h" #include "vnode.h" #include <rxrpc/call.h> #include "internal.h" #if 0 static int afs_file_open(struct inode *inode, struct file *file); static int afs_file_release(struct inode *inode, struct file *file); #endif static int afs_file_readpage(struct file *file, struct page *page); static void afs_file_invalidatepage(struct page *page, unsigned long offset); static int afs_file_releasepage(struct page *page, gfp_t gfp_flags); struct inode_operations afs_file_inode_operations = { .getattr = afs_inode_getattr, }; const struct address_space_operations afs_fs_aops = { .readpage = afs_file_readpage, .sync_page = block_sync_page, .set_page_dirty = __set_page_dirty_nobuffers, .releasepage = afs_file_releasepage, .invalidatepage = afs_file_invalidatepage, }; /*****************************************************************************/ /* * deal with notification that a page was read from the cache */ #ifdef AFS_CACHING_SUPPORT static void afs_file_readpage_read_complete(void *cookie_data, struct page *page, void *data, int error) { _enter("%p,%p,%p,%d", cookie_data, page, data, error); if (error) SetPageError(page); else SetPageUptodate(page); unlock_page(page); } /* end afs_file_readpage_read_complete() */ #endif /*****************************************************************************/ /* * deal with notification that a page was written to the cache */ #ifdef AFS_CACHING_SUPPORT static void afs_file_readpage_write_complete(void *cookie_data, struct page *page, void *data, int error) { _enter("%p,%p,%p,%d", cookie_data, page, data, error); unlock_page(page); } /* end afs_file_readpage_write_complete() */ #endif /*****************************************************************************/ /* * 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() */ /*****************************************************************************/ /* * get a page cookie for the specified page */ #ifdef AFS_CACHING_SUPPORT int afs_cache_get_page_cookie(struct page *page, struct cachefs_page **_page_cookie) { int ret; _enter(""); ret = cachefs_page_get_private(page,_page_cookie, GFP_NOIO); _leave(" = %d", ret); return ret; } /* end afs_cache_get_page_cookie() */ #endif /*****************************************************************************/ /* * 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() */