diff options
Diffstat (limited to 'fs/fscache')
| -rw-r--r-- | fs/fscache/Kconfig | 1 | ||||
| -rw-r--r-- | fs/fscache/Makefile | 1 | ||||
| -rw-r--r-- | fs/fscache/internal.h | 4 | ||||
| -rw-r--r-- | fs/fscache/io.c | 116 | ||||
| -rw-r--r-- | fs/fscache/page.c | 2 | ||||
| -rw-r--r-- | fs/fscache/stats.c | 1 |
6 files changed, 124 insertions, 1 deletions
diff --git a/fs/fscache/Kconfig b/fs/fscache/Kconfig index 5e796e6c38e5..427efa73b9bd 100644 --- a/fs/fscache/Kconfig +++ b/fs/fscache/Kconfig @@ -2,6 +2,7 @@ config FSCACHE tristate "General filesystem local caching manager" + select NETFS_SUPPORT help This option enables a generic filesystem caching manager that can be used by various network and other filesystems to cache data locally. diff --git a/fs/fscache/Makefile b/fs/fscache/Makefile index 79e08e05ef84..3b2ffa93ac18 100644 --- a/fs/fscache/Makefile +++ b/fs/fscache/Makefile @@ -7,6 +7,7 @@ fscache-y := \ cache.o \ cookie.o \ fsdef.o \ + io.o \ main.o \ netfs.o \ object.o \ diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h index 08e91efbce53..c483863b740a 100644 --- a/fs/fscache/internal.h +++ b/fs/fscache/internal.h @@ -142,6 +142,10 @@ extern int fscache_wait_for_operation_activation(struct fscache_object *, atomic_t *, atomic_t *); extern void fscache_invalidate_writes(struct fscache_cookie *); +struct fscache_retrieval *fscache_alloc_retrieval(struct fscache_cookie *cookie, + struct address_space *mapping, + fscache_rw_complete_t end_io_func, + void *context); /* * proc.c diff --git a/fs/fscache/io.c b/fs/fscache/io.c new file mode 100644 index 000000000000..8ecc1141802f --- /dev/null +++ b/fs/fscache/io.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Cache data I/O routines + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define FSCACHE_DEBUG_LEVEL PAGE +#include <linux/module.h> +#define FSCACHE_USE_NEW_IO_API +#include <linux/fscache-cache.h> +#include <linux/slab.h> +#include <linux/netfs.h> +#include "internal.h" + +/* + * Start a cache read operation. + * - we return: + * -ENOMEM - out of memory, some pages may be being read + * -ERESTARTSYS - interrupted, some pages may be being read + * -ENOBUFS - no backing object or space available in which to cache any + * pages not being read + * -ENODATA - no data available in the backing object for some or all of + * the pages + * 0 - dispatched a read on all pages + */ +int __fscache_begin_read_operation(struct netfs_read_request *rreq, + struct fscache_cookie *cookie) +{ + struct fscache_retrieval *op; + struct fscache_object *object; + bool wake_cookie = false; + int ret; + + _enter("rr=%08x", rreq->debug_id); + + fscache_stat(&fscache_n_retrievals); + + if (hlist_empty(&cookie->backing_objects)) + goto nobufs; + + if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { + _leave(" = -ENOBUFS [invalidating]"); + return -ENOBUFS; + } + + ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); + + if (fscache_wait_for_deferred_lookup(cookie) < 0) + return -ERESTARTSYS; + + op = fscache_alloc_retrieval(cookie, NULL, NULL, NULL); + if (!op) + return -ENOMEM; + trace_fscache_page_op(cookie, NULL, &op->op, fscache_page_op_retr_multi); + + spin_lock(&cookie->lock); + + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) + goto nobufs_unlock; + object = hlist_entry(cookie->backing_objects.first, + struct fscache_object, cookie_link); + + __fscache_use_cookie(cookie); + atomic_inc(&object->n_reads); + __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); + + if (fscache_submit_op(object, &op->op) < 0) + goto nobufs_unlock_dec; + spin_unlock(&cookie->lock); + + fscache_stat(&fscache_n_retrieval_ops); + + /* we wait for the operation to become active, and then process it + * *here*, in this thread, and not in the thread pool */ + ret = fscache_wait_for_operation_activation( + object, &op->op, + __fscache_stat(&fscache_n_retrieval_op_waits), + __fscache_stat(&fscache_n_retrievals_object_dead)); + if (ret < 0) + goto error; + + /* ask the cache to honour the operation */ + ret = object->cache->ops->begin_read_operation(rreq, op); + +error: + if (ret == -ENOMEM) + fscache_stat(&fscache_n_retrievals_nomem); + else if (ret == -ERESTARTSYS) + fscache_stat(&fscache_n_retrievals_intr); + else if (ret == -ENODATA) + fscache_stat(&fscache_n_retrievals_nodata); + else if (ret < 0) + fscache_stat(&fscache_n_retrievals_nobufs); + else + fscache_stat(&fscache_n_retrievals_ok); + + fscache_put_retrieval(op); + _leave(" = %d", ret); + return ret; + +nobufs_unlock_dec: + atomic_dec(&object->n_reads); + wake_cookie = __fscache_unuse_cookie(cookie); +nobufs_unlock: + spin_unlock(&cookie->lock); + fscache_put_retrieval(op); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); +nobufs: + fscache_stat(&fscache_n_retrievals_nobufs); + _leave(" = -ENOBUFS"); + return -ENOBUFS; +} +EXPORT_SYMBOL(__fscache_begin_read_operation); diff --git a/fs/fscache/page.c b/fs/fscache/page.c index 26af6fdf1538..991b0a871744 100644 --- a/fs/fscache/page.c +++ b/fs/fscache/page.c @@ -299,7 +299,7 @@ static void fscache_release_retrieval_op(struct fscache_operation *_op) /* * allocate a retrieval op */ -static struct fscache_retrieval *fscache_alloc_retrieval( +struct fscache_retrieval *fscache_alloc_retrieval( struct fscache_cookie *cookie, struct address_space *mapping, fscache_rw_complete_t end_io_func, diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c index a5aa93ece8c5..a7c3ed89a3e0 100644 --- a/fs/fscache/stats.c +++ b/fs/fscache/stats.c @@ -278,5 +278,6 @@ int fscache_stats_show(struct seq_file *m, void *v) atomic_read(&fscache_n_cache_stale_objects), atomic_read(&fscache_n_cache_retired_objects), atomic_read(&fscache_n_cache_culled_objects)); + netfs_stats_show(m); return 0; } |