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-rw-r--r--fs/afs/file.c733
1 files changed, 733 insertions, 0 deletions
diff --git a/fs/afs/file.c b/fs/afs/file.c
new file mode 100644
index 000000000..960b64268
--- /dev/null
+++ b/fs/afs/file.c
@@ -0,0 +1,733 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AFS filesystem file handling
+ *
+ * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/gfp.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/mm.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_readpages(struct file *filp, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages);
+
+const struct file_operations afs_file_operations = {
+ .open = afs_open,
+ .release = afs_release,
+ .llseek = generic_file_llseek,
+ .read_iter = generic_file_read_iter,
+ .write_iter = afs_file_write,
+ .mmap = afs_file_mmap,
+ .splice_read = generic_file_splice_read,
+ .splice_write = iter_file_splice_write,
+ .fsync = afs_fsync,
+ .lock = afs_lock,
+ .flock = afs_flock,
+};
+
+const struct inode_operations afs_file_inode_operations = {
+ .getattr = afs_getattr,
+ .setattr = afs_setattr,
+ .permission = afs_permission,
+};
+
+const struct address_space_operations afs_fs_aops = {
+ .readpage = afs_readpage,
+ .readpages = afs_readpages,
+ .set_page_dirty = afs_set_page_dirty,
+ .launder_page = afs_launder_page,
+ .releasepage = afs_releasepage,
+ .invalidatepage = afs_invalidatepage,
+ .write_begin = afs_write_begin,
+ .write_end = afs_write_end,
+ .writepage = afs_writepage,
+ .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 (wbk && 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;
+
+ _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
+
+ key = afs_request_key(vnode->volume->cell);
+ if (IS_ERR(key)) {
+ ret = PTR_ERR(key);
+ goto error;
+ }
+
+ 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;
+
+ if (file->f_mode & FMODE_WRITE) {
+ ret = afs_cache_wb_key(vnode, af);
+ if (ret < 0)
+ goto error_af;
+ }
+
+ if (file->f_flags & O_TRUNC)
+ set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
+
+ file->private_data = af;
+ _leave(" = 0");
+ return 0;
+
+error_af:
+ kfree(af);
+error_key:
+ key_put(key);
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * release an AFS file or directory and discard its key
+ */
+int afs_release(struct inode *inode, struct file *file)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct afs_file *af = file->private_data;
+ int ret = 0;
+
+ _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
+
+ if ((file->f_mode & FMODE_WRITE))
+ ret = vfs_fsync(file, 0);
+
+ 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(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Dispose of a ref to a read record.
+ */
+void afs_put_read(struct afs_read *req)
+{
+ int i;
+
+ if (refcount_dec_and_test(&req->usage)) {
+ if (req->pages) {
+ for (i = 0; i < req->nr_pages; i++)
+ if (req->pages[i])
+ put_page(req->pages[i]);
+ if (req->pages != req->array)
+ kfree(req->pages);
+ }
+ kfree(req);
+ }
+}
+
+#ifdef CONFIG_AFS_FSCACHE
+/*
+ * deal with notification that a page was read from the cache
+ */
+static void afs_file_readpage_read_complete(struct page *page,
+ void *data,
+ int error)
+{
+ _enter("%p,%p,%d", page, data, error);
+
+ /* if the read completes with an error, we just unlock the page and let
+ * the VM reissue the readpage */
+ if (!error)
+ SetPageUptodate(page);
+ unlock_page(page);
+}
+#endif
+
+static void afs_fetch_data_success(struct afs_operation *op)
+{
+ struct afs_vnode *vnode = op->file[0].vnode;
+
+ _enter("op=%08x", op->debug_id);
+ afs_vnode_commit_status(op, &op->file[0]);
+ afs_stat_v(vnode, n_fetches);
+ atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes);
+}
+
+static void afs_fetch_data_put(struct afs_operation *op)
+{
+ afs_put_read(op->fetch.req);
+}
+
+static const struct afs_operation_ops afs_fetch_data_operation = {
+ .issue_afs_rpc = afs_fs_fetch_data,
+ .issue_yfs_rpc = yfs_fs_fetch_data,
+ .success = afs_fetch_data_success,
+ .aborted = afs_check_for_remote_deletion,
+ .put = afs_fetch_data_put,
+};
+
+/*
+ * Fetch file data from the volume.
+ */
+int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *req)
+{
+ struct afs_operation *op;
+
+ _enter("%s{%llx:%llu.%u},%x,,,",
+ vnode->volume->name,
+ vnode->fid.vid,
+ vnode->fid.vnode,
+ vnode->fid.unique,
+ key_serial(key));
+
+ op = afs_alloc_operation(key, vnode->volume);
+ if (IS_ERR(op))
+ return PTR_ERR(op);
+
+ afs_op_set_vnode(op, 0, vnode);
+
+ op->fetch.req = afs_get_read(req);
+ op->ops = &afs_fetch_data_operation;
+ return afs_do_sync_operation(op);
+}
+
+/*
+ * read page from file, directory or symlink, given a key to use
+ */
+int afs_page_filler(void *data, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct afs_read *req;
+ struct key *key = data;
+ int ret;
+
+ _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
+
+ BUG_ON(!PageLocked(page));
+
+ ret = -ESTALE;
+ if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
+ goto error;
+
+ /* is it cached? */
+#ifdef CONFIG_AFS_FSCACHE
+ ret = fscache_read_or_alloc_page(vnode->cache,
+ page,
+ afs_file_readpage_read_complete,
+ NULL,
+ GFP_KERNEL);
+#else
+ ret = -ENOBUFS;
+#endif
+ switch (ret) {
+ /* read BIO submitted (page in cache) */
+ case 0:
+ break;
+
+ /* page not yet cached */
+ case -ENODATA:
+ _debug("cache said ENODATA");
+ goto go_on;
+
+ /* page will not be cached */
+ case -ENOBUFS:
+ _debug("cache said ENOBUFS");
+
+ fallthrough;
+ default:
+ go_on:
+ req = kzalloc(struct_size(req, array, 1), GFP_KERNEL);
+ if (!req)
+ goto enomem;
+
+ /* We request a full page. If the page is a partial one at the
+ * end of the file, the server will return a short read and the
+ * unmarshalling code will clear the unfilled space.
+ */
+ refcount_set(&req->usage, 1);
+ req->pos = (loff_t)page->index << PAGE_SHIFT;
+ req->len = PAGE_SIZE;
+ req->nr_pages = 1;
+ req->pages = req->array;
+ req->pages[0] = page;
+ get_page(page);
+
+ /* read the contents of the file from the server into the
+ * page */
+ ret = afs_fetch_data(vnode, key, req);
+ afs_put_read(req);
+
+ 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 CONFIG_AFS_FSCACHE
+ fscache_uncache_page(vnode->cache, page);
+#endif
+ BUG_ON(PageFsCache(page));
+
+ if (ret == -EINTR ||
+ ret == -ENOMEM ||
+ ret == -ERESTARTSYS ||
+ ret == -EAGAIN)
+ goto error;
+ goto io_error;
+ }
+
+ SetPageUptodate(page);
+
+ /* send the page to the cache */
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page) &&
+ fscache_write_page(vnode->cache, page, vnode->status.size,
+ GFP_KERNEL) != 0) {
+ fscache_uncache_page(vnode->cache, page);
+ BUG_ON(PageFsCache(page));
+ }
+#endif
+ unlock_page(page);
+ }
+
+ _leave(" = 0");
+ return 0;
+
+io_error:
+ SetPageError(page);
+ goto error;
+enomem:
+ ret = -ENOMEM;
+error:
+ unlock_page(page);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * read page from file, directory or symlink, given a file to nominate the key
+ * to be used
+ */
+static int afs_readpage(struct file *file, struct page *page)
+{
+ struct key *key;
+ int ret;
+
+ if (file) {
+ 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)->cell);
+ if (IS_ERR(key)) {
+ ret = PTR_ERR(key);
+ } else {
+ ret = afs_page_filler(key, page);
+ key_put(key);
+ }
+ }
+ return ret;
+}
+
+/*
+ * Make pages available as they're filled.
+ */
+static void afs_readpages_page_done(struct afs_read *req)
+{
+#ifdef CONFIG_AFS_FSCACHE
+ struct afs_vnode *vnode = req->vnode;
+#endif
+ struct page *page = req->pages[req->index];
+
+ req->pages[req->index] = NULL;
+ SetPageUptodate(page);
+
+ /* send the page to the cache */
+#ifdef CONFIG_AFS_FSCACHE
+ if (PageFsCache(page) &&
+ fscache_write_page(vnode->cache, page, vnode->status.size,
+ GFP_KERNEL) != 0) {
+ fscache_uncache_page(vnode->cache, page);
+ BUG_ON(PageFsCache(page));
+ }
+#endif
+ unlock_page(page);
+ put_page(page);
+}
+
+/*
+ * Read a contiguous set of pages.
+ */
+static int afs_readpages_one(struct file *file, struct address_space *mapping,
+ struct list_head *pages)
+{
+ struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+ struct afs_read *req;
+ struct list_head *p;
+ struct page *first, *page;
+ struct key *key = afs_file_key(file);
+ pgoff_t index;
+ int ret, n, i;
+
+ /* Count the number of contiguous pages at the front of the list. Note
+ * that the list goes prev-wards rather than next-wards.
+ */
+ first = lru_to_page(pages);
+ index = first->index + 1;
+ n = 1;
+ for (p = first->lru.prev; p != pages; p = p->prev) {
+ page = list_entry(p, struct page, lru);
+ if (page->index != index)
+ break;
+ index++;
+ n++;
+ }
+
+ req = kzalloc(struct_size(req, array, n), GFP_NOFS);
+ if (!req)
+ return -ENOMEM;
+
+ refcount_set(&req->usage, 1);
+ req->vnode = vnode;
+ req->page_done = afs_readpages_page_done;
+ req->pos = first->index;
+ req->pos <<= PAGE_SHIFT;
+ req->pages = req->array;
+
+ /* Transfer the pages to the request. We add them in until one fails
+ * to add to the LRU and then we stop (as that'll make a hole in the
+ * contiguous run.
+ *
+ * Note that it's possible for the file size to change whilst we're
+ * doing this, but we rely on the server returning less than we asked
+ * for if the file shrank. We also rely on this to deal with a partial
+ * page at the end of the file.
+ */
+ do {
+ page = lru_to_page(pages);
+ list_del(&page->lru);
+ index = page->index;
+ if (add_to_page_cache_lru(page, mapping, index,
+ readahead_gfp_mask(mapping))) {
+#ifdef CONFIG_AFS_FSCACHE
+ fscache_uncache_page(vnode->cache, page);
+#endif
+ put_page(page);
+ break;
+ }
+
+ req->pages[req->nr_pages++] = page;
+ req->len += PAGE_SIZE;
+ } while (req->nr_pages < n);
+
+ if (req->nr_pages == 0) {
+ kfree(req);
+ return 0;
+ }
+
+ ret = afs_fetch_data(vnode, key, req);
+ if (ret < 0)
+ goto error;
+
+ task_io_account_read(PAGE_SIZE * req->nr_pages);
+ afs_put_read(req);
+ return 0;
+
+error:
+ if (ret == -ENOENT) {
+ _debug("got NOENT from server"
+ " - marking file deleted and stale");
+ set_bit(AFS_VNODE_DELETED, &vnode->flags);
+ ret = -ESTALE;
+ }
+
+ for (i = 0; i < req->nr_pages; i++) {
+ page = req->pages[i];
+ if (page) {
+#ifdef CONFIG_AFS_FSCACHE
+ fscache_uncache_page(vnode->cache, page);
+#endif
+ SetPageError(page);
+ unlock_page(page);
+ }
+ }
+
+ afs_put_read(req);
+ return ret;
+}
+
+/*
+ * read a set of pages
+ */
+static int afs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct key *key = afs_file_key(file);
+ struct afs_vnode *vnode;
+ int ret = 0;
+
+ _enter("{%d},{%lu},,%d",
+ key_serial(key), mapping->host->i_ino, nr_pages);
+
+ ASSERT(key != NULL);
+
+ vnode = AFS_FS_I(mapping->host);
+ if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
+ _leave(" = -ESTALE");
+ return -ESTALE;
+ }
+
+ /* attempt to read as many of the pages as possible */
+#ifdef CONFIG_AFS_FSCACHE
+ ret = fscache_read_or_alloc_pages(vnode->cache,
+ mapping,
+ pages,
+ &nr_pages,
+ afs_file_readpage_read_complete,
+ NULL,
+ mapping_gfp_mask(mapping));
+#else
+ ret = -ENOBUFS;
+#endif
+
+ switch (ret) {
+ /* all pages are being read from the cache */
+ case 0:
+ BUG_ON(!list_empty(pages));
+ BUG_ON(nr_pages != 0);
+ _leave(" = 0 [reading all]");
+ return 0;
+
+ /* there were pages that couldn't be read from the cache */
+ case -ENODATA:
+ case -ENOBUFS:
+ break;
+
+ /* other error */
+ default:
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ while (!list_empty(pages)) {
+ ret = afs_readpages_one(file, mapping, pages);
+ if (ret < 0)
+ break;
+ }
+
+ _leave(" = %d [netting]", ret);
+ return ret;
+}
+
+/*
+ * Adjust the dirty region of the page on truncation or full invalidation,
+ * getting rid of the markers altogether if the region is entirely invalidated.
+ */
+static void afs_invalidate_dirty(struct page *page, unsigned int offset,
+ unsigned int length)
+{
+ struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+ unsigned long priv;
+ unsigned int f, t, end = offset + length;
+
+ priv = page_private(page);
+
+ /* we clean up only if the entire page is being invalidated */
+ if (offset == 0 && length == thp_size(page))
+ goto full_invalidate;
+
+ /* If the page was dirtied by page_mkwrite(), the PTE stays writable
+ * and we don't get another notification to tell us to expand it
+ * again.
+ */
+ if (afs_is_page_dirty_mmapped(priv))
+ return;
+
+ /* We may need to shorten the dirty region */
+ f = afs_page_dirty_from(priv);
+ t = afs_page_dirty_to(priv);
+
+ if (t <= offset || f >= end)
+ return; /* Doesn't overlap */
+
+ if (f < offset && t > end)
+ return; /* Splits the dirty region - just absorb it */
+
+ if (f >= offset && t <= end)
+ goto undirty;
+
+ if (f < offset)
+ t = offset;
+ else
+ f = end;
+ if (f == t)
+ goto undirty;
+
+ priv = afs_page_dirty(f, t);
+ set_page_private(page, priv);
+ trace_afs_page_dirty(vnode, tracepoint_string("trunc"), page->index, priv);
+ return;
+
+undirty:
+ trace_afs_page_dirty(vnode, tracepoint_string("undirty"), page->index, priv);
+ clear_page_dirty_for_io(page);
+full_invalidate:
+ priv = (unsigned long)detach_page_private(page);
+ trace_afs_page_dirty(vnode, tracepoint_string("inval"), page->index, priv);
+}
+
+/*
+ * invalidate part or all of a page
+ * - release a page and clean up its private data if offset is 0 (indicating
+ * the entire page)
+ */
+static void afs_invalidatepage(struct page *page, unsigned int offset,
+ unsigned int length)
+{
+ _enter("{%lu},%u,%u", page->index, offset, length);
+
+ BUG_ON(!PageLocked(page));
+
+#ifdef CONFIG_AFS_FSCACHE
+ /* we clean up only if the entire page is being invalidated */
+ if (offset == 0 && length == PAGE_SIZE) {
+ if (PageFsCache(page)) {
+ struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+ fscache_wait_on_page_write(vnode->cache, page);
+ fscache_uncache_page(vnode->cache, page);
+ }
+ }
+#endif
+
+ if (PagePrivate(page))
+ afs_invalidate_dirty(page, offset, length);
+
+ _leave("");
+}
+
+/*
+ * release a page and clean up its private state if it's not busy
+ * - return true if the page can now be released, false if not
+ */
+static int afs_releasepage(struct page *page, gfp_t gfp_flags)
+{
+ struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+ unsigned long priv;
+
+ _enter("{{%llx:%llu}[%lu],%lx},%x",
+ vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
+ gfp_flags);
+
+ /* deny if page is being written to the cache and the caller hasn't
+ * elected to wait */
+#ifdef CONFIG_AFS_FSCACHE
+ if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
+ _leave(" = F [cache busy]");
+ return 0;
+ }
+#endif
+
+ if (PagePrivate(page)) {
+ priv = (unsigned long)detach_page_private(page);
+ trace_afs_page_dirty(vnode, tracepoint_string("rel"),
+ page->index, priv);
+ }
+
+ /* indicate that the page can be released */
+ _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;
+}
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