// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache interface to CacheFiles
*
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/slab.h>
#include <linux/mount.h>
+#include <linux/xattr.h>
+#include <linux/file.h>
+#include <linux/falloc.h>
+#include <trace/events/fscache.h>
#include "internal.h"
-struct cachefiles_lookup_data {
- struct cachefiles_xattr *auxdata; /* auxiliary data */
- char *key; /* key path */
-};
-
-static int cachefiles_attr_changed(struct fscache_object *_object);
+static atomic_t cachefiles_object_debug_id;
/*
- * allocate an object record for a cookie lookup and prepare the lookup data
+ * Allocate a cache object record.
*/
-static struct fscache_object *cachefiles_alloc_object(
- struct fscache_cache *_cache,
- struct fscache_cookie *cookie)
+static
+struct cachefiles_object *cachefiles_alloc_object(struct fscache_cookie *cookie)
{
- struct cachefiles_lookup_data *lookup_data;
+ struct fscache_volume *vcookie = cookie->volume;
+ struct cachefiles_volume *volume = vcookie->cache_priv;
struct cachefiles_object *object;
- struct cachefiles_cache *cache;
- struct cachefiles_xattr *auxdata;
- unsigned keylen, auxlen;
- void *buffer, *p;
- char *key;
- cache = container_of(_cache, struct cachefiles_cache, cache);
+ _enter("{%s},%x,", vcookie->key, cookie->debug_id);
- _enter("{%s},%x,", cache->cache.identifier, cookie->debug_id);
-
- lookup_data = kmalloc(sizeof(*lookup_data), cachefiles_gfp);
- if (!lookup_data)
- goto nomem_lookup_data;
-
- /* create a new object record and a temporary leaf image */
- object = kmem_cache_alloc(cachefiles_object_jar, cachefiles_gfp);
+ object = kmem_cache_zalloc(cachefiles_object_jar, GFP_KERNEL);
if (!object)
- goto nomem_object;
-
- ASSERTCMP(object->backer, ==, NULL);
+ return NULL;
- BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
- atomic_set(&object->usage, 1);
+ refcount_set(&object->ref, 1);
- fscache_object_init(&object->fscache, cookie, &cache->cache);
+ spin_lock_init(&object->lock);
+ INIT_LIST_HEAD(&object->cache_link);
+ object->volume = volume;
+ object->debug_id = atomic_inc_return(&cachefiles_object_debug_id);
+ object->cookie = fscache_get_cookie(cookie, fscache_cookie_get_attach_object);
- object->type = cookie->def->type;
-
- /* get hold of the raw key
- * - stick the length on the front and leave space on the back for the
- * encoder
- */
- buffer = kmalloc((2 + 512) + 3, cachefiles_gfp);
- if (!buffer)
- goto nomem_buffer;
-
- keylen = cookie->key_len;
- if (keylen <= sizeof(cookie->inline_key))
- p = cookie->inline_key;
- else
- p = cookie->key;
- memcpy(buffer + 2, p, keylen);
-
- *(uint16_t *)buffer = keylen;
- ((char *)buffer)[keylen + 2] = 0;
- ((char *)buffer)[keylen + 3] = 0;
- ((char *)buffer)[keylen + 4] = 0;
-
- /* turn the raw key into something that can work with as a filename */
- key = cachefiles_cook_key(buffer, keylen + 2, object->type);
- if (!key)
- goto nomem_key;
-
- /* get hold of the auxiliary data and prepend the object type */
- auxdata = buffer;
- auxlen = cookie->aux_len;
- if (auxlen) {
- if (auxlen <= sizeof(cookie->inline_aux))
- p = cookie->inline_aux;
- else
- p = cookie->aux;
- memcpy(auxdata->data, p, auxlen);
- }
-
- auxdata->len = auxlen + 1;
- auxdata->type = cookie->type;
-
- lookup_data->auxdata = auxdata;
- lookup_data->key = key;
- object->lookup_data = lookup_data;
-
- _leave(" = %x [%p]", object->fscache.debug_id, lookup_data);
- return &object->fscache;
-
-nomem_key:
- kfree(buffer);
-nomem_buffer:
- BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
- kmem_cache_free(cachefiles_object_jar, object);
- fscache_object_destroyed(&cache->cache);
-nomem_object:
- kfree(lookup_data);
-nomem_lookup_data:
- _leave(" = -ENOMEM");
- return ERR_PTR(-ENOMEM);
+ fscache_count_object(vcookie->cache);
+ trace_cachefiles_ref(object->debug_id, cookie->debug_id, 1,
+ cachefiles_obj_new);
+ return object;
}
/*
- * attempt to look up the nominated node in this cache
- * - return -ETIMEDOUT to be scheduled again
+ * Note that an object has been seen.
*/
-static int cachefiles_lookup_object(struct fscache_object *_object)
+void cachefiles_see_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why)
{
- struct cachefiles_lookup_data *lookup_data;
- struct cachefiles_object *parent, *object;
- struct cachefiles_cache *cache;
- const struct cred *saved_cred;
- int ret;
-
- _enter("{OBJ%x}", _object->debug_id);
-
- cache = container_of(_object->cache, struct cachefiles_cache, cache);
- parent = container_of(_object->parent,
- struct cachefiles_object, fscache);
- object = container_of(_object, struct cachefiles_object, fscache);
- lookup_data = object->lookup_data;
-
- ASSERTCMP(lookup_data, !=, NULL);
-
- /* look up the key, creating any missing bits */
- cachefiles_begin_secure(cache, &saved_cred);
- ret = cachefiles_walk_to_object(parent, object,
- lookup_data->key,
- lookup_data->auxdata);
- cachefiles_end_secure(cache, saved_cred);
-
- /* polish off by setting the attributes of non-index files */
- if (ret == 0 &&
- object->fscache.cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX)
- cachefiles_attr_changed(&object->fscache);
-
- if (ret < 0 && ret != -ETIMEDOUT) {
- if (ret != -ENOBUFS)
- pr_warn("Lookup failed error %d\n", ret);
- fscache_object_lookup_error(&object->fscache);
- }
-
- _leave(" [%d]", ret);
- return ret;
+ trace_cachefiles_ref(object->debug_id, object->cookie->debug_id,
+ refcount_read(&object->ref), why);
}
/*
- * indication of lookup completion
+ * Increment the usage count on an object;
*/
-static void cachefiles_lookup_complete(struct fscache_object *_object)
+struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why)
{
- struct cachefiles_object *object;
-
- object = container_of(_object, struct cachefiles_object, fscache);
-
- _enter("{OBJ%x,%p}", object->fscache.debug_id, object->lookup_data);
+ int r;
- if (object->lookup_data) {
- kfree(object->lookup_data->key);
- kfree(object->lookup_data->auxdata);
- kfree(object->lookup_data);
- object->lookup_data = NULL;
- }
+ __refcount_inc(&object->ref, &r);
+ trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, r, why);
+ return object;
}
/*
- * increment the usage count on an inode object (may fail if unmounting)
+ * dispose of a reference to an object
*/
-static
-struct fscache_object *cachefiles_grab_object(struct fscache_object *_object,
- enum fscache_obj_ref_trace why)
+void cachefiles_put_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why)
{
- struct cachefiles_object *object =
- container_of(_object, struct cachefiles_object, fscache);
- int u;
+ unsigned int object_debug_id = object->debug_id;
+ unsigned int cookie_debug_id = object->cookie->debug_id;
+ struct fscache_cache *cache;
+ bool done;
+ int r;
+
+ done = __refcount_dec_and_test(&object->ref, &r);
+ trace_cachefiles_ref(object_debug_id, cookie_debug_id, r, why);
+ if (done) {
+ _debug("- kill object OBJ%x", object_debug_id);
+
+ ASSERTCMP(object->file, ==, NULL);
- _enter("{OBJ%x,%d}", _object->debug_id, atomic_read(&object->usage));
+ kfree(object->d_name);
-#ifdef CACHEFILES_DEBUG_SLAB
- ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
-#endif
+ cache = object->volume->cache->cache;
+ fscache_put_cookie(object->cookie, fscache_cookie_put_object);
+ object->cookie = NULL;
+ kmem_cache_free(cachefiles_object_jar, object);
+ fscache_uncount_object(cache);
+ }
- u = atomic_inc_return(&object->usage);
- trace_cachefiles_ref(object, _object->cookie,
- (enum cachefiles_obj_ref_trace)why, u);
- return &object->fscache;
+ _leave("");
}
/*
- * update the auxiliary data for an object object on disk
+ * Adjust the size of a cache file if necessary to match the DIO size. We keep
+ * the EOF marker a multiple of DIO blocks so that we don't fall back to doing
+ * non-DIO for a partial block straddling the EOF, but we also have to be
+ * careful of someone expanding the file and accidentally accreting the
+ * padding.
*/
-static void cachefiles_update_object(struct fscache_object *_object)
+static int cachefiles_adjust_size(struct cachefiles_object *object)
{
- struct cachefiles_object *object;
- struct cachefiles_xattr *auxdata;
- struct cachefiles_cache *cache;
- struct fscache_cookie *cookie;
- const struct cred *saved_cred;
- const void *aux;
- unsigned auxlen;
+ struct iattr newattrs;
+ struct file *file = object->file;
+ uint64_t ni_size;
+ loff_t oi_size;
+ int ret;
- _enter("{OBJ%x}", _object->debug_id);
+ ni_size = object->cookie->object_size;
+ ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE);
- object = container_of(_object, struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache, struct cachefiles_cache,
- cache);
+ _enter("{OBJ%x},[%llu]",
+ object->debug_id, (unsigned long long) ni_size);
- if (!fscache_use_cookie(_object)) {
- _leave(" [relinq]");
- return;
- }
+ if (!file)
+ return -ENOBUFS;
- cookie = object->fscache.cookie;
- auxlen = cookie->aux_len;
+ oi_size = i_size_read(file_inode(file));
+ if (oi_size == ni_size)
+ return 0;
- if (!auxlen) {
- fscache_unuse_cookie(_object);
- _leave(" [no aux]");
- return;
- }
+ inode_lock(file_inode(file));
- auxdata = kmalloc(2 + auxlen + 3, cachefiles_gfp);
- if (!auxdata) {
- fscache_unuse_cookie(_object);
- _leave(" [nomem]");
- return;
+ /* if there's an extension to a partial page at the end of the backing
+ * file, we need to discard the partial page so that we pick up new
+ * data after it */
+ if (oi_size & ~PAGE_MASK && ni_size > oi_size) {
+ _debug("discard tail %llx", oi_size);
+ newattrs.ia_valid = ATTR_SIZE;
+ newattrs.ia_size = oi_size & PAGE_MASK;
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = notify_change(&init_user_ns, file->f_path.dentry,
+ &newattrs, NULL);
+ if (ret < 0)
+ goto truncate_failed;
}
- aux = (auxlen <= sizeof(cookie->inline_aux)) ?
- cookie->inline_aux : cookie->aux;
+ newattrs.ia_valid = ATTR_SIZE;
+ newattrs.ia_size = ni_size;
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = notify_change(&init_user_ns, file->f_path.dentry,
+ &newattrs, NULL);
- memcpy(auxdata->data, aux, auxlen);
- fscache_unuse_cookie(_object);
+truncate_failed:
+ inode_unlock(file_inode(file));
- auxdata->len = auxlen + 1;
- auxdata->type = cookie->type;
+ if (ret < 0)
+ trace_cachefiles_io_error(NULL, file_inode(file), ret,
+ cachefiles_trace_notify_change_error);
+ if (ret == -EIO) {
+ cachefiles_io_error_obj(object, "Size set failed");
+ ret = -ENOBUFS;
+ }
- cachefiles_begin_secure(cache, &saved_cred);
- cachefiles_update_object_xattr(object, auxdata);
- cachefiles_end_secure(cache, saved_cred);
- kfree(auxdata);
- _leave("");
+ _leave(" = %d", ret);
+ return ret;
}
/*
- * discard the resources pinned by an object and effect retirement if
- * requested
+ * Attempt to look up the nominated node in this cache
*/
-static void cachefiles_drop_object(struct fscache_object *_object)
+static bool cachefiles_lookup_cookie(struct fscache_cookie *cookie)
{
struct cachefiles_object *object;
- struct cachefiles_cache *cache;
+ struct cachefiles_cache *cache = cookie->volume->cache->cache_priv;
const struct cred *saved_cred;
- struct inode *inode;
- blkcnt_t i_blocks = 0;
+ bool success;
- ASSERT(_object);
+ object = cachefiles_alloc_object(cookie);
+ if (!object)
+ goto fail;
- object = container_of(_object, struct cachefiles_object, fscache);
+ _enter("{OBJ%x}", object->debug_id);
- _enter("{OBJ%x,%d}",
- object->fscache.debug_id, atomic_read(&object->usage));
+ if (!cachefiles_cook_key(object))
+ goto fail_put;
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
+ cookie->cache_priv = object;
-#ifdef CACHEFILES_DEBUG_SLAB
- ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
-#endif
+ cachefiles_begin_secure(cache, &saved_cred);
- /* We need to tidy the object up if we did in fact manage to open it.
- * It's possible for us to get here before the object is fully
- * initialised if the parent goes away or the object gets retired
- * before we set it up.
- */
- if (object->dentry) {
- /* delete retired objects */
- if (test_bit(FSCACHE_OBJECT_RETIRED, &object->fscache.flags) &&
- _object != cache->cache.fsdef
- ) {
- _debug("- retire object OBJ%x", object->fscache.debug_id);
- inode = d_backing_inode(object->dentry);
- if (inode)
- i_blocks = inode->i_blocks;
-
- cachefiles_begin_secure(cache, &saved_cred);
- cachefiles_delete_object(cache, object);
- cachefiles_end_secure(cache, saved_cred);
- }
+ success = cachefiles_look_up_object(object);
+ if (!success)
+ goto fail_withdraw;
- /* close the filesystem stuff attached to the object */
- if (object->backer != object->dentry)
- dput(object->backer);
- object->backer = NULL;
- }
+ cachefiles_see_object(object, cachefiles_obj_see_lookup_cookie);
+
+ spin_lock(&cache->object_list_lock);
+ list_add(&object->cache_link, &cache->object_list);
+ spin_unlock(&cache->object_list_lock);
+ cachefiles_adjust_size(object);
- /* note that the object is now inactive */
- if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags))
- cachefiles_mark_object_inactive(cache, object, i_blocks);
+ cachefiles_end_secure(cache, saved_cred);
+ _leave(" = t");
+ return true;
- dput(object->dentry);
- object->dentry = NULL;
+fail_withdraw:
+ cachefiles_end_secure(cache, saved_cred);
+ cachefiles_see_object(object, cachefiles_obj_see_lookup_failed);
+ fscache_caching_failed(cookie);
+ _debug("failed c=%08x o=%08x", cookie->debug_id, object->debug_id);
+ /* The caller holds an access count on the cookie, so we need them to
+ * drop it before we can withdraw the object.
+ */
+ return false;
- _leave("");
+fail_put:
+ cachefiles_put_object(object, cachefiles_obj_put_alloc_fail);
+fail:
+ return false;
}
/*
- * dispose of a reference to an object
+ * Shorten the backing object to discard any dirty data and free up
+ * any unused granules.
*/
-void cachefiles_put_object(struct fscache_object *_object,
- enum fscache_obj_ref_trace why)
+static bool cachefiles_shorten_object(struct cachefiles_object *object,
+ struct file *file, loff_t new_size)
{
- struct cachefiles_object *object;
- struct fscache_cache *cache;
- int u;
-
- ASSERT(_object);
-
- object = container_of(_object, struct cachefiles_object, fscache);
-
- _enter("{OBJ%x,%d}",
- object->fscache.debug_id, atomic_read(&object->usage));
-
-#ifdef CACHEFILES_DEBUG_SLAB
- ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
-#endif
-
- ASSERTIFCMP(object->fscache.parent,
- object->fscache.parent->n_children, >, 0);
-
- u = atomic_dec_return(&object->usage);
- trace_cachefiles_ref(object, _object->cookie,
- (enum cachefiles_obj_ref_trace)why, u);
- ASSERTCMP(u, !=, -1);
- if (u == 0) {
- _debug("- kill object OBJ%x", object->fscache.debug_id);
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct inode *inode = file_inode(file);
+ loff_t i_size, dio_size;
+ int ret;
- ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
- ASSERTCMP(object->fscache.parent, ==, NULL);
- ASSERTCMP(object->backer, ==, NULL);
- ASSERTCMP(object->dentry, ==, NULL);
- ASSERTCMP(object->fscache.n_ops, ==, 0);
- ASSERTCMP(object->fscache.n_children, ==, 0);
+ dio_size = round_up(new_size, CACHEFILES_DIO_BLOCK_SIZE);
+ i_size = i_size_read(inode);
+
+ trace_cachefiles_trunc(object, inode, i_size, dio_size,
+ cachefiles_trunc_shrink);
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = vfs_truncate(&file->f_path, dio_size);
+ if (ret < 0) {
+ trace_cachefiles_io_error(object, file_inode(file), ret,
+ cachefiles_trace_trunc_error);
+ cachefiles_io_error_obj(object, "Trunc-to-size failed %d", ret);
+ cachefiles_remove_object_xattr(cache, object, file->f_path.dentry);
+ return false;
+ }
- if (object->lookup_data) {
- kfree(object->lookup_data->key);
- kfree(object->lookup_data->auxdata);
- kfree(object->lookup_data);
- object->lookup_data = NULL;
+ if (new_size < dio_size) {
+ trace_cachefiles_trunc(object, inode, dio_size, new_size,
+ cachefiles_trunc_dio_adjust);
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_fallocate(file, FALLOC_FL_ZERO_RANGE,
+ new_size, dio_size);
+ if (ret < 0) {
+ trace_cachefiles_io_error(object, file_inode(file), ret,
+ cachefiles_trace_fallocate_error);
+ cachefiles_io_error_obj(object, "Trunc-to-dio-size failed %d", ret);
+ cachefiles_remove_object_xattr(cache, object, file->f_path.dentry);
+ return false;
}
-
- cache = object->fscache.cache;
- fscache_object_destroy(&object->fscache);
- kmem_cache_free(cachefiles_object_jar, object);
- fscache_object_destroyed(cache);
}
- _leave("");
+ return true;
}
/*
- * sync a cache
+ * Resize the backing object.
*/
-static void cachefiles_sync_cache(struct fscache_cache *_cache)
+static void cachefiles_resize_cookie(struct netfs_cache_resources *cres,
+ loff_t new_size)
{
- struct cachefiles_cache *cache;
+ struct cachefiles_object *object = cachefiles_cres_object(cres);
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct fscache_cookie *cookie = object->cookie;
const struct cred *saved_cred;
- int ret;
+ struct file *file = cachefiles_cres_file(cres);
+ loff_t old_size = cookie->object_size;
- _enter("%s", _cache->tag->name);
+ _enter("%llu->%llu", old_size, new_size);
- cache = container_of(_cache, struct cachefiles_cache, cache);
-
- /* make sure all pages pinned by operations on behalf of the netfs are
- * written to disc */
- cachefiles_begin_secure(cache, &saved_cred);
- down_read(&cache->mnt->mnt_sb->s_umount);
- ret = sync_filesystem(cache->mnt->mnt_sb);
- up_read(&cache->mnt->mnt_sb->s_umount);
- cachefiles_end_secure(cache, saved_cred);
+ if (new_size < old_size) {
+ cachefiles_begin_secure(cache, &saved_cred);
+ cachefiles_shorten_object(object, file, new_size);
+ cachefiles_end_secure(cache, saved_cred);
+ object->cookie->object_size = new_size;
+ return;
+ }
- if (ret == -EIO)
- cachefiles_io_error(cache,
- "Attempt to sync backing fs superblock"
- " returned error %d",
- ret);
+ /* The file is being expanded. We don't need to do anything
+ * particularly. cookie->initial_size doesn't change and so the point
+ * at which we have to download before doesn't change.
+ */
+ cookie->object_size = new_size;
}
/*
- * check if the backing cache is updated to FS-Cache
- * - called by FS-Cache when evaluates if need to invalidate the cache
+ * Commit changes to the object as we drop it.
*/
-static int cachefiles_check_consistency(struct fscache_operation *op)
+static void cachefiles_commit_object(struct cachefiles_object *object,
+ struct cachefiles_cache *cache)
{
- struct cachefiles_object *object;
- struct cachefiles_cache *cache;
- const struct cred *saved_cred;
- int ret;
+ bool update = false;
- _enter("{OBJ%x}", op->object->debug_id);
+ if (test_and_clear_bit(FSCACHE_COOKIE_LOCAL_WRITE, &object->cookie->flags))
+ update = true;
+ if (test_and_clear_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags))
+ update = true;
+ if (update)
+ cachefiles_set_object_xattr(object);
- object = container_of(op->object, struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
+ if (test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags))
+ cachefiles_commit_tmpfile(cache, object);
+}
- cachefiles_begin_secure(cache, &saved_cred);
- ret = cachefiles_check_auxdata(object);
- cachefiles_end_secure(cache, saved_cred);
+/*
+ * Finalise and object and close the VFS structs that we have.
+ */
+static void cachefiles_clean_up_object(struct cachefiles_object *object,
+ struct cachefiles_cache *cache)
+{
+ if (test_bit(FSCACHE_COOKIE_RETIRED, &object->cookie->flags)) {
+ if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
+ cachefiles_see_object(object, cachefiles_obj_see_clean_delete);
+ _debug("- inval object OBJ%x", object->debug_id);
+ cachefiles_delete_object(object, FSCACHE_OBJECT_WAS_RETIRED);
+ } else {
+ cachefiles_see_object(object, cachefiles_obj_see_clean_drop_tmp);
+ _debug("- inval object OBJ%x tmpfile", object->debug_id);
+ }
+ } else {
+ cachefiles_see_object(object, cachefiles_obj_see_clean_commit);
+ cachefiles_commit_object(object, cache);
+ }
- _leave(" = %d", ret);
- return ret;
+ cachefiles_unmark_inode_in_use(object, object->file);
+ if (object->file) {
+ fput(object->file);
+ object->file = NULL;
+ }
}
/*
- * notification the attributes on an object have changed
- * - called with reads/writes excluded by FS-Cache
+ * Withdraw caching for a cookie.
*/
-static int cachefiles_attr_changed(struct fscache_object *_object)
+static void cachefiles_withdraw_cookie(struct fscache_cookie *cookie)
{
- struct cachefiles_object *object;
- struct cachefiles_cache *cache;
+ struct cachefiles_object *object = cookie->cache_priv;
+ struct cachefiles_cache *cache = object->volume->cache;
const struct cred *saved_cred;
- struct iattr newattrs;
- uint64_t ni_size;
- loff_t oi_size;
- int ret;
-
- ni_size = _object->store_limit_l;
-
- _enter("{OBJ%x},[%llu]",
- _object->debug_id, (unsigned long long) ni_size);
-
- object = container_of(_object, struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
-
- if (ni_size == object->i_size)
- return 0;
-
- if (!object->backer)
- return -ENOBUFS;
- ASSERT(d_is_reg(object->backer));
+ _enter("o=%x", object->debug_id);
+ cachefiles_see_object(object, cachefiles_obj_see_withdraw_cookie);
- fscache_set_store_limit(&object->fscache, ni_size);
-
- oi_size = i_size_read(d_backing_inode(object->backer));
- if (oi_size == ni_size)
- return 0;
-
- cachefiles_begin_secure(cache, &saved_cred);
- inode_lock(d_inode(object->backer));
-
- /* if there's an extension to a partial page at the end of the backing
- * file, we need to discard the partial page so that we pick up new
- * data after it */
- if (oi_size & ~PAGE_MASK && ni_size > oi_size) {
- _debug("discard tail %llx", oi_size);
- newattrs.ia_valid = ATTR_SIZE;
- newattrs.ia_size = oi_size & PAGE_MASK;
- ret = notify_change(&init_user_ns, object->backer, &newattrs, NULL);
- if (ret < 0)
- goto truncate_failed;
+ if (!list_empty(&object->cache_link)) {
+ spin_lock(&cache->object_list_lock);
+ cachefiles_see_object(object, cachefiles_obj_see_withdrawal);
+ list_del_init(&object->cache_link);
+ spin_unlock(&cache->object_list_lock);
}
- newattrs.ia_valid = ATTR_SIZE;
- newattrs.ia_size = ni_size;
- ret = notify_change(&init_user_ns, object->backer, &newattrs, NULL);
-
-truncate_failed:
- inode_unlock(d_inode(object->backer));
- cachefiles_end_secure(cache, saved_cred);
-
- if (ret == -EIO) {
- fscache_set_store_limit(&object->fscache, 0);
- cachefiles_io_error_obj(object, "Size set failed");
- ret = -ENOBUFS;
+ if (object->file) {
+ cachefiles_begin_secure(cache, &saved_cred);
+ cachefiles_clean_up_object(object, cache);
+ cachefiles_end_secure(cache, saved_cred);
}
- _leave(" = %d", ret);
- return ret;
+ cookie->cache_priv = NULL;
+ cachefiles_put_object(object, cachefiles_obj_put_detach);
}
/*
- * Invalidate an object
+ * Invalidate the storage associated with a cookie.
*/
-static void cachefiles_invalidate_object(struct fscache_operation *op)
+static bool cachefiles_invalidate_cookie(struct fscache_cookie *cookie)
{
- struct cachefiles_object *object;
- struct cachefiles_cache *cache;
- const struct cred *saved_cred;
- struct path path;
- uint64_t ni_size;
- int ret;
+ struct cachefiles_object *object = cookie->cache_priv;
+ struct file *new_file, *old_file;
+ bool old_tmpfile;
- object = container_of(op->object, struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
+ _enter("o=%x,[%llu]", object->debug_id, object->cookie->object_size);
- ni_size = op->object->store_limit_l;
+ old_tmpfile = test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags);
- _enter("{OBJ%x},[%llu]",
- op->object->debug_id, (unsigned long long)ni_size);
+ if (!object->file) {
+ fscache_resume_after_invalidation(cookie);
+ _leave(" = t [light]");
+ return true;
+ }
- if (object->backer) {
- ASSERT(d_is_reg(object->backer));
+ new_file = cachefiles_create_tmpfile(object);
+ if (IS_ERR(new_file))
+ goto failed;
- fscache_set_store_limit(&object->fscache, ni_size);
+ /* Substitute the VFS target */
+ _debug("sub");
+ spin_lock(&object->lock);
- path.dentry = object->backer;
- path.mnt = cache->mnt;
+ old_file = object->file;
+ object->file = new_file;
+ object->content_info = CACHEFILES_CONTENT_NO_DATA;
+ set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags);
+ set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags);
- cachefiles_begin_secure(cache, &saved_cred);
- ret = vfs_truncate(&path, 0);
- if (ret == 0)
- ret = vfs_truncate(&path, ni_size);
- cachefiles_end_secure(cache, saved_cred);
+ spin_unlock(&object->lock);
+ _debug("subbed");
+
+ /* Allow I/O to take place again */
+ fscache_resume_after_invalidation(cookie);
+
+ if (old_file) {
+ if (!old_tmpfile) {
+ struct cachefiles_volume *volume = object->volume;
+ struct dentry *fan = volume->fanout[(u8)cookie->key_hash];
- if (ret != 0) {
- fscache_set_store_limit(&object->fscache, 0);
- if (ret == -EIO)
- cachefiles_io_error_obj(object,
- "Invalidate failed");
+ inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
+ cachefiles_bury_object(volume->cache, object, fan,
+ old_file->f_path.dentry,
+ FSCACHE_OBJECT_INVALIDATED);
}
+ fput(old_file);
}
- fscache_op_complete(op, true);
- _leave("");
-}
+ _leave(" = t");
+ return true;
-/*
- * dissociate a cache from all the pages it was backing
- */
-static void cachefiles_dissociate_pages(struct fscache_cache *cache)
-{
- _enter("");
+failed:
+ _leave(" = f");
+ return false;
}
const struct fscache_cache_ops cachefiles_cache_ops = {
.name = "cachefiles",
- .alloc_object = cachefiles_alloc_object,
- .lookup_object = cachefiles_lookup_object,
- .lookup_complete = cachefiles_lookup_complete,
- .grab_object = cachefiles_grab_object,
- .update_object = cachefiles_update_object,
- .invalidate_object = cachefiles_invalidate_object,
- .drop_object = cachefiles_drop_object,
- .put_object = cachefiles_put_object,
- .sync_cache = cachefiles_sync_cache,
- .attr_changed = cachefiles_attr_changed,
- .read_or_alloc_page = cachefiles_read_or_alloc_page,
- .read_or_alloc_pages = cachefiles_read_or_alloc_pages,
- .allocate_page = cachefiles_allocate_page,
- .allocate_pages = cachefiles_allocate_pages,
- .write_page = cachefiles_write_page,
- .uncache_page = cachefiles_uncache_page,
- .dissociate_pages = cachefiles_dissociate_pages,
- .check_consistency = cachefiles_check_consistency,
- .begin_read_operation = cachefiles_begin_read_operation,
+ .acquire_volume = cachefiles_acquire_volume,
+ .free_volume = cachefiles_free_volume,
+ .lookup_cookie = cachefiles_lookup_cookie,
+ .withdraw_cookie = cachefiles_withdraw_cookie,
+ .invalidate_cookie = cachefiles_invalidate_cookie,
+ .begin_operation = cachefiles_begin_operation,
+ .resize_cookie = cachefiles_resize_cookie,
+ .prepare_to_write = cachefiles_prepare_to_write,
};
projects / linux-block.git / blobdiff