Merge tag 'afs-next-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS updates from David Howells:
 "kAFS filesystem driver overhaul.

  The major points of the overhaul are:

   (1) Preliminary groundwork is laid for supporting network-namespacing
       of kAFS. The remainder of the namespacing work requires some way
       to pass namespace information to submounts triggered by an
       automount. This requires something like the mount overhaul that's
       in progress.

   (2) sockaddr_rxrpc is used in preference to in_addr for holding
       addresses internally and add support for talking to the YFS VL
       server. With this, kAFS can do everything over IPv6 as well as
       IPv4 if it's talking to servers that support it.

   (3) Callback handling is overhauled to be generally passive rather
       than active. 'Callbacks' are promises by the server to tell us
       about data and metadata changes. Callbacks are now checked when
       we next touch an inode rather than actively going and looking for
       it where possible.

   (4) File access permit caching is overhauled to store the caching
       information per-inode rather than per-directory, shared over
       subordinate files. Whilst older AFS servers only allow ACLs on
       directories (shared to the files in that directory), newer AFS
       servers break that restriction.

       To improve memory usage and to make it easier to do mass-key
       removal, permit combinations are cached and shared.

   (5) Cell database management is overhauled to allow lighter locks to
       be used and to make cell records autonomous state machines that
       look after getting their own DNS records and cleaning themselves
       up, in particular preventing races in acquiring and relinquishing
       the fscache token for the cell.

   (6) Volume caching is overhauled. The afs_vlocation record is got rid
       of to simplify things and the superblock is now keyed on the cell
       and the numeric volume ID only. The volume record is tied to a
       superblock and normal superblock management is used to mediate
       the lifetime of the volume fscache token.

   (7) File server record caching is overhauled to make server records
       independent of cells and volumes. A server can be in multiple
       cells (in such a case, the administrator must make sure that the
       VL services for all cells correctly reflect the volumes shared
       between those cells).

       Server records are now indexed using the UUID of the server
       rather than the address since a server can have multiple
       addresses.

   (8) File server rotation is overhauled to handle VMOVED, VBUSY (and
       similar), VOFFLINE and VNOVOL indications and to handle rotation
       both of servers and addresses of those servers. The rotation will
       also wait and retry if the server says it is busy.

   (9) Data writeback is overhauled. Each inode no longer stores a list
       of modified sections tagged with the key that authorised it in
       favour of noting the modified region of a page in page->private
       and storing a list of keys that made modifications in the inode.

       This simplifies things and allows other keys to be used to
       actually write to the server if a key that made a modification
       becomes useless.

  (10) Writable mmap() is implemented. This allows a kernel to be build
       entirely on AFS.

  Note that Pre AFS-3.4 servers are no longer supported, though this can
  be added back if necessary (AFS-3.4 was released in 1998)"

* tag 'afs-next-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (35 commits)
  afs: Protect call->state changes against signals
  afs: Trace page dirty/clean
  afs: Implement shared-writeable mmap
  afs: Get rid of the afs_writeback record
  afs: Introduce a file-private data record
  afs: Use a dynamic port if 7001 is in use
  afs: Fix directory read/modify race
  afs: Trace the sending of pages
  afs: Trace the initiation and completion of client calls
  afs: Fix documentation on # vs % prefix in mount source specification
  afs: Fix total-length calculation for multiple-page send
  afs: Only progress call state at end of Tx phase from rxrpc callback
  afs: Make use of the YFS service upgrade to fully support IPv6
  afs: Overhaul volume and server record caching and fileserver rotation
  afs: Move server rotation code into its own file
  afs: Add an address list concept
  afs: Overhaul cell database management
  afs: Overhaul permit caching
  afs: Overhaul the callback handling
  afs: Rename struct afs_call server member to cm_server
  ...

1 files changed, 154 insertions, 40 deletions

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 510cba15fa56..a39192ced99e 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -19,11 +19,11 @@
 #include <linux/task_io_accounting_ops.h>
 #include "internal.h"
 
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
 static int afs_readpage(struct file *file, struct page *page);
 static void afs_invalidatepage(struct page *page, unsigned int offset,
 			       unsigned int length);
 static int afs_releasepage(struct page *page, gfp_t gfp_flags);
-static int afs_launder_page(struct page *page);
 
 static int afs_readpages(struct file *filp, struct address_space *mapping,
 			 struct list_head *pages, unsigned nr_pages);
@@ -35,7 +35,7 @@ const struct file_operations afs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read_iter	= generic_file_read_iter,
 	.write_iter	= afs_file_write,
-	.mmap		= generic_file_readonly_mmap,
+	.mmap		= afs_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= afs_fsync,
 	.lock		= afs_lock,
@@ -62,12 +62,63 @@ const struct address_space_operations afs_fs_aops = {
 	.writepages	= afs_writepages,
 };
 
+static const struct vm_operations_struct afs_vm_ops = {
+	.fault		= filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= afs_page_mkwrite,
+};
+
+/*
+ * Discard a pin on a writeback key.
+ */
+void afs_put_wb_key(struct afs_wb_key *wbk)
+{
+	if (refcount_dec_and_test(&wbk->usage)) {
+		key_put(wbk->key);
+		kfree(wbk);
+	}
+}
+
+/*
+ * Cache key for writeback.
+ */
+int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
+{
+	struct afs_wb_key *wbk, *p;
+
+	wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL);
+	if (!wbk)
+		return -ENOMEM;
+	refcount_set(&wbk->usage, 2);
+	wbk->key = af->key;
+
+	spin_lock(&vnode->wb_lock);
+	list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
+		if (p->key == wbk->key)
+			goto found;
+	}
+
+	key_get(wbk->key);
+	list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
+	spin_unlock(&vnode->wb_lock);
+	af->wb = wbk;
+	return 0;
+
+found:
+	refcount_inc(&p->usage);
+	spin_unlock(&vnode->wb_lock);
+	af->wb = p;
+	kfree(wbk);
+	return 0;
+}
+
 /*
  * open an AFS file or directory and attach a key to it
  */
 int afs_open(struct inode *inode, struct file *file)
 {
 	struct afs_vnode *vnode = AFS_FS_I(inode);
+	struct afs_file *af;
 	struct key *key;
 	int ret;
 
@@ -75,19 +126,38 @@ int afs_open(struct inode *inode, struct file *file)
 
 	key = afs_request_key(vnode->volume->cell);
 	if (IS_ERR(key)) {
-		_leave(" = %ld [key]", PTR_ERR(key));
-		return PTR_ERR(key);
+		ret = PTR_ERR(key);
+		goto error;
 	}
 
-	ret = afs_validate(vnode, key);
-	if (ret < 0) {
-		_leave(" = %d [val]", ret);
-		return ret;
+	af = kzalloc(sizeof(*af), GFP_KERNEL);
+	if (!af) {
+		ret = -ENOMEM;
+		goto error_key;
 	}
+	af->key = key;
+
+	ret = afs_validate(vnode, key);
+	if (ret < 0)
+		goto error_af;
 
-	file->private_data = key;
+	if (file->f_mode & FMODE_WRITE) {
+		ret = afs_cache_wb_key(vnode, af);
+		if (ret < 0)
+			goto error_af;
+	}
+	
+	file->private_data = af;
 	_leave(" = 0");
 	return 0;
+
+error_af:
+	kfree(af);
+error_key:
+	key_put(key);
+error:
+	_leave(" = %d", ret);
+	return ret;
 }
 
 /*
@@ -96,10 +166,16 @@ int afs_open(struct inode *inode, struct file *file)
 int afs_release(struct inode *inode, struct file *file)
 {
 	struct afs_vnode *vnode = AFS_FS_I(inode);
+	struct afs_file *af = file->private_data;
 
 	_enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
 
-	key_put(file->private_data);
+	file->private_data = NULL;
+	if (af->wb)
+		afs_put_wb_key(af->wb);
+	key_put(af->key);
+	kfree(af);
+	afs_prune_wb_keys(vnode);
 	_leave(" = 0");
 	return 0;
 }
@@ -138,6 +214,37 @@ static void afs_file_readpage_read_complete(struct page *page,
 #endif
 
 /*
+ * Fetch file data from the volume.
+ */
+int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *desc)
+{
+	struct afs_fs_cursor fc;
+	int ret;
+
+	_enter("%s{%x:%u.%u},%x,,,",
+	       vnode->volume->name,
+	       vnode->fid.vid,
+	       vnode->fid.vnode,
+	       vnode->fid.unique,
+	       key_serial(key));
+
+	ret = -ERESTARTSYS;
+	if (afs_begin_vnode_operation(&fc, vnode, key)) {
+		while (afs_select_fileserver(&fc)) {
+			fc.cb_break = vnode->cb_break + vnode->cb_s_break;
+			afs_fs_fetch_data(&fc, desc);
+		}
+
+		afs_check_for_remote_deletion(&fc, fc.vnode);
+		afs_vnode_commit_status(&fc, vnode, fc.cb_break);
+		ret = afs_end_vnode_operation(&fc);
+	}
+
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
  * read page from file, directory or symlink, given a key to use
  */
 int afs_page_filler(void *data, struct page *page)
@@ -199,8 +306,13 @@ int afs_page_filler(void *data, struct page *page)
 
 		/* read the contents of the file from the server into the
 		 * page */
-		ret = afs_vnode_fetch_data(vnode, key, req);
+		ret = afs_fetch_data(vnode, key, req);
 		afs_put_read(req);
+
+		if (ret >= 0 && S_ISDIR(inode->i_mode) &&
+		    !afs_dir_check_page(inode, page))
+			ret = -EIO;
+
 		if (ret < 0) {
 			if (ret == -ENOENT) {
 				_debug("got NOENT from server"
@@ -259,12 +371,12 @@ static int afs_readpage(struct file *file, struct page *page)
 	int ret;
 
 	if (file) {
-		key = file->private_data;
+		key = afs_file_key(file);
 		ASSERT(key != NULL);
 		ret = afs_page_filler(key, page);
 	} else {
 		struct inode *inode = page->mapping->host;
-		key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);
+		key = afs_request_key(AFS_FS_S(inode->i_sb)->cell);
 		if (IS_ERR(key)) {
 			ret = PTR_ERR(key);
 		} else {
@@ -281,7 +393,7 @@ static int afs_readpage(struct file *file, struct page *page)
 static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req)
 {
 #ifdef CONFIG_AFS_FSCACHE
-	struct afs_vnode *vnode = call->reply;
+	struct afs_vnode *vnode = call->reply[0];
 #endif
 	struct page *page = req->pages[req->index];
 
@@ -310,7 +422,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 	struct afs_read *req;
 	struct list_head *p;
 	struct page *first, *page;
-	struct key *key = file->private_data;
+	struct key *key = afs_file_key(file);
 	pgoff_t index;
 	int ret, n, i;
 
@@ -369,7 +481,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		return 0;
 	}
 
-	ret = afs_vnode_fetch_data(vnode, key, req);
+	ret = afs_fetch_data(vnode, key, req);
 	if (ret < 0)
 		goto error;
 
@@ -406,7 +518,7 @@ error:
 static int afs_readpages(struct file *file, struct address_space *mapping,
 			 struct list_head *pages, unsigned nr_pages)
 {
-	struct key *key = file->private_data;
+	struct key *key = afs_file_key(file);
 	struct afs_vnode *vnode;
 	int ret = 0;
 
@@ -464,16 +576,6 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
 }
 
 /*
- * write back a dirty page
- */
-static int afs_launder_page(struct page *page)
-{
-	_enter("{%lu}", page->index);
-
-	return 0;
-}
-
-/*
  * invalidate part or all of a page
  * - release a page and clean up its private data if offset is 0 (indicating
  *   the entire page)
@@ -481,7 +583,8 @@ static int afs_launder_page(struct page *page)
 static void afs_invalidatepage(struct page *page, unsigned int offset,
 			       unsigned int length)
 {
-	struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
+	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+	unsigned long priv;
 
 	_enter("{%lu},%u,%u", page->index, offset, length);
 
@@ -498,13 +601,11 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
 #endif
 
 		if (PagePrivate(page)) {
-			if (wb && !PageWriteback(page)) {
-				set_page_private(page, 0);
-				afs_put_writeback(wb);
-			}
-
-			if (!page_private(page))
-				ClearPagePrivate(page);
+			priv = page_private(page);
+			trace_afs_page_dirty(vnode, tracepoint_string("inval"),
+					     page->index, priv);
+			set_page_private(page, 0);
+			ClearPagePrivate(page);
 		}
 	}
 
@@ -517,8 +618,8 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
  */
 static int afs_releasepage(struct page *page, gfp_t gfp_flags)
 {
-	struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
 	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+	unsigned long priv;
 
 	_enter("{{%x:%u}[%lu],%lx},%x",
 	       vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
@@ -534,10 +635,10 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
 #endif
 
 	if (PagePrivate(page)) {
-		if (wb) {
-			set_page_private(page, 0);
-			afs_put_writeback(wb);
-		}
+		priv = page_private(page);
+		trace_afs_page_dirty(vnode, tracepoint_string("rel"),
+				     page->index, priv);
+		set_page_private(page, 0);
 		ClearPagePrivate(page);
 	}
 
@@ -545,3 +646,16 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
 	_leave(" = T");
 	return 1;
 }
+
+/*
+ * Handle setting up a memory mapping on an AFS file.
+ */
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	int ret;
+
+	ret = generic_file_mmap(file, vma);
+	if (ret == 0)
+		vma->vm_ops = &afs_vm_ops;
+	return ret;
+}