From: David Howells <dhowells@redhat.com> To: Trond Myklebust <trondmy@hammerspace.com>, Anna Schumaker <anna.schumaker@netapp.com>, Steve French <sfrench@samba.org>, Dominique Martinet <asmadeus@codewreck.org> Cc: dhowells@redhat.com, Jeff Layton <jlayton@redhat.com>, Matthew Wilcox <willy@infradead.org>, Alexander Viro <viro@zeniv.linux.org.uk>, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 39/76] cachefiles: Implement new fscache I/O backend API Date: Fri, 20 Nov 2020 15:11:02 +0000 Message-ID: <160588506244.3465195.14835834211702469652.stgit@warthog.procyon.org.uk> (raw) In-Reply-To: <160588455242.3465195.3214733858273019178.stgit@warthog.procyon.org.uk> Implement the new fscache I/O backend API in cachefiles. The cachefiles_object struct carries a non-accounted file to the cachefiles object (so that it doesn't cause ENFILE). Signed-off-by: David Howells <dhowells@redhat.com> --- fs/cachefiles/Makefile | 1 + fs/cachefiles/interface.c | 13 +++++++ fs/cachefiles/internal.h | 19 ++++++++++ fs/cachefiles/io.c | 85 +++++++++++++++++++++++++++++++++++++++++++++ fs/cachefiles/namei.c | 3 ++ 5 files changed, 120 insertions(+), 1 deletion(-) create mode 100644 fs/cachefiles/io.c diff --git a/fs/cachefiles/Makefile b/fs/cachefiles/Makefile index 3455d3646547..d894d317d6e7 100644 --- a/fs/cachefiles/Makefile +++ b/fs/cachefiles/Makefile @@ -7,6 +7,7 @@ cachefiles-y := \ bind.o \ daemon.o \ interface.o \ + io.o \ key.o \ main.o \ namei.o \ diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index 3f6d2be690bc..dc8c875223bb 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -453,6 +453,18 @@ static unsigned int cachefiles_get_object_usage(const struct fscache_object *_ob return atomic_read(&object->usage); } +static const struct fscache_op_ops cachefiles_io_ops = { + .wait_for_operation = __fscache_wait_for_operation, + .end_operation = __fscache_end_operation, + .read = cachefiles_read, + .write = cachefiles_write, +}; + +static void cachefiles_begin_operation(struct fscache_op_resources *opr) +{ + opr->ops = &cachefiles_io_ops; +} + const struct fscache_cache_ops cachefiles_cache_ops = { .name = "cachefiles", .alloc_object = cachefiles_alloc_object, @@ -466,4 +478,5 @@ const struct fscache_cache_ops cachefiles_cache_ops = { .put_object = cachefiles_put_object, .get_object_usage = cachefiles_get_object_usage, .sync_cache = cachefiles_sync_cache, + .begin_operation = cachefiles_begin_operation, }; diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index 16d15291a629..caa6dfbaf333 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -115,6 +115,22 @@ extern const struct fscache_cache_ops cachefiles_cache_ops; extern struct fscache_object *cachefiles_grab_object(struct fscache_object *_object, enum fscache_obj_ref_trace why); +/* + * io.c + */ +extern int cachefiles_read(struct fscache_op_resources *opr, + loff_t start_pos, + struct iov_iter *iter, + bool seek_data, + fscache_io_terminated_t term_func, + void *term_func_priv); +extern int cachefiles_write(struct fscache_op_resources *opr, + loff_t start_pos, + struct iov_iter *iter, + fscache_io_terminated_t term_func, + void *term_func_priv); +extern bool cachefiles_open_object(struct cachefiles_object *obj); + /* * key.c */ @@ -216,7 +232,8 @@ do { \ \ ___cache = container_of((object)->fscache.cache, \ struct cachefiles_cache, cache); \ - cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ + cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \ + object->fscache.debug_id); \ } while (0) diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c new file mode 100644 index 000000000000..f1d5976aa28c --- /dev/null +++ b/fs/cachefiles/io.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Data I/O routines + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/mount.h> +#include <linux/slab.h> +#include <linux/file.h> +#include <linux/uio.h> +#include <linux/xattr.h> +#include "internal.h" +#include <trace/events/fscache.h> + +/* + * Initiate a read from the cache. + */ +int cachefiles_read(struct fscache_op_resources *opr, + loff_t start_pos, + struct iov_iter *iter, + bool seek_data, + fscache_io_terminated_t term_func, + void *term_func_priv) +{ + fscache_wait_for_operation(opr, FSCACHE_WANT_READ); + fscache_count_io_operation(opr->object->cookie); + if (term_func) + term_func(term_func_priv, -ENODATA); + return -ENODATA; +} + +/* + * Initiate a write to the cache. + */ +int cachefiles_write(struct fscache_op_resources *opr, + loff_t start_pos, + struct iov_iter *iter, + fscache_io_terminated_t term_func, + void *term_func_priv) +{ + fscache_wait_for_operation(opr, FSCACHE_WANT_WRITE); + fscache_count_io_operation(opr->object->cookie); + if (term_func) + term_func(term_func_priv, -ENOBUFS); + return -ENOBUFS; +} + +/* + * Open a cache object. + */ +bool cachefiles_open_object(struct cachefiles_object *object) +{ + struct cachefiles_cache *cache = + container_of(object->fscache.cache, struct cachefiles_cache, cache); + struct file *file; + struct path path; + + path.mnt = cache->mnt; + path.dentry = object->backer; + + file = open_with_fake_path(&path, + O_RDWR | O_LARGEFILE | O_DIRECT, + d_backing_inode(object->backer), + cache->cache_cred); + if (IS_ERR(file)) + goto error; + + if (!S_ISREG(file_inode(file)->i_mode)) + goto error_file; + + if (unlikely(!file->f_op->read_iter) || + unlikely(!file->f_op->write_iter)) { + pr_notice("Cache does not support read_iter and write_iter\n"); + goto error_file; + } + + object->backing_file = file; + return true; + +error_file: + fput(file); +error: + return false; +} diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index 0a7e2031efa2..4b515054d92e 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -490,6 +490,9 @@ bool cachefiles_walk_to_object(struct cachefiles_object *parent, } else { BUG(); // TODO: open file in data-class subdir } + + if (!cachefiles_open_object(object)) + goto check_error; } if (object->new)
next prev parent reply index Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-20 15:02 [RFC PATCH 00/76] fscache: Modernisation David Howells 2020-11-20 15:02 ` [RFC PATCH 01/76] nfs, cifs, ceph, 9p: Disable use of fscache prior to its rewrite David Howells 2020-11-20 15:02 ` [RFC PATCH 02/76] afs: Disable use of the fscache I/O routines David Howells 2020-11-20 15:03 ` [RFC PATCH 03/76] fscache: Add a cookie debug ID and use that in traces David Howells 2020-11-20 15:03 ` [RFC PATCH 04/76] fscache: Procfile to display cookies David Howells 2020-11-20 15:03 ` [RFC PATCH 05/76] fscache: Remove the old I/O API David Howells 2020-11-20 15:03 ` [RFC PATCH 06/76] fscache: Remove the netfs data from the cookie David Howells 2020-11-20 15:04 ` [RFC PATCH 07/76] fscache: Remove struct fscache_cookie_def David Howells 2020-11-20 15:04 ` [RFC PATCH 08/76] fscache: Remove store_limit* from struct fscache_object David Howells 2020-11-20 15:04 ` [RFC PATCH 09/76] fscache: Remove fscache_check_consistency() David Howells 2020-11-20 15:04 ` [RFC PATCH 10/76] fscache: Remove fscache_attr_changed() David Howells 2020-11-20 15:04 ` [RFC PATCH 11/76] fscache: Remove obsolete stats David Howells 2020-11-20 15:05 ` [RFC PATCH 12/76] fscache: Remove old I/O tracepoints David Howells 2020-11-20 15:05 ` [RFC PATCH 13/76] fscache: Temporarily disable fscache_invalidate() David Howells 2020-11-20 15:05 ` [RFC PATCH 14/76] fscache: Remove the I/O operation manager David Howells 2020-11-20 15:05 ` [RFC PATCH 15/76] fscache: Change %p in format strings to something else David Howells 2020-11-20 15:06 ` [RFC PATCH 16/76] cachefiles: " David Howells 2020-11-20 15:06 ` [RFC PATCH 17/76] iov_iter: Add ITER_XARRAY David Howells 2020-11-20 15:06 ` [RFC PATCH 18/76] vm: Add wait/unlock functions for PG_fscache David Howells 2020-11-20 15:06 ` [RFC PATCH 19/76] mm: Implement readahead_control pageset expansion David Howells 2020-11-20 15:06 ` [RFC PATCH 20/76] mm: Stop generic_file_buffered_read() from grabbing a superfluous page David Howells 2020-11-20 15:07 ` [RFC PATCH 21/76] vfs: Export rw_verify_area() for use by cachefiles David Howells 2020-11-20 15:07 ` [RFC PATCH 22/76] vfs: Provide S_CACHE_FILE inode flag David Howells 2020-11-20 15:07 ` [RFC PATCH 23/76] cachefiles: Remove tree of active files and use " David Howells 2020-11-20 15:07 ` [RFC PATCH 24/76] fscache: Provide a simple thread pool for running ops asynchronously David Howells 2020-11-20 15:08 ` [RFC PATCH 26/76] fscache: Rewrite the I/O API based on iov_iter David Howells 2020-11-20 15:08 ` [RFC PATCH 27/76] fscache: Keep track of size of a file last set independently on the server David Howells 2020-11-20 15:08 ` [RFC PATCH 28/76] fscache, cachefiles: Fix disabled histogram warnings David Howells 2020-11-20 15:08 ` [RFC PATCH 29/76] fscache: Recast assertion in terms of cookie not being an index David Howells 2020-11-20 15:08 ` [RFC PATCH 30/76] vfs, fscache: Force ->write_inode() to occur if cookie pinned for writeback David Howells 2020-11-20 15:09 ` [RFC PATCH 31/76] fscache: Allow ->put_super() to be used to wait for cache operations David Howells 2020-11-20 15:09 ` [RFC PATCH 32/76] netfs: Make a netfs helper module David Howells 2020-11-20 15:09 ` [RFC PATCH 33/76] netfs: Provide readahead and readpage netfs helpers David Howells 2020-11-20 15:09 ` [RFC PATCH 34/76] netfs: Use the cache David Howells 2020-11-20 15:10 ` [RFC PATCH 35/76] fscache: read-helper: Add tracepoints David Howells 2020-11-20 15:10 ` [RFC PATCH 36/76] cachefiles: Remove some redundant checks on unsigned values David Howells 2020-11-20 15:10 ` [RFC PATCH 37/76] cachefiles: trace: Log coherency checks David Howells 2020-11-20 15:10 ` [RFC PATCH 38/76] cachefiles: Split cachefiles_drop_object() up a bit David Howells 2020-11-20 15:11 ` David Howells [this message] 2020-11-20 15:11 ` [RFC PATCH 40/76] cachefiles: Merge object->backer into object->dentry David Howells 2020-11-20 15:11 ` [RFC PATCH 41/76] cachefiles: Implement a content-present indicator and bitmap David Howells 2020-11-20 15:11 ` [RFC PATCH 42/76] cachefiles: Shape requests from the fscache read helper David Howells 2020-11-20 15:11 ` [RFC PATCH 43/76] cachefiles: Round the cachefile size up to DIO block size David Howells 2020-11-20 15:12 ` [RFC PATCH 44/76] cachefiles: Implement read and write parts of new I/O API David Howells 2020-11-20 15:12 ` [RFC PATCH 45/76] cachefiles: Add I/O tracepoints David Howells 2020-11-20 15:12 ` [RFC PATCH 46/76] fscache: Display cache-specific data in /proc/fs/fscache/objects David Howells 2020-11-20 15:12 ` [RFC PATCH 47/76] fscache: Remove more obsolete stats David Howells 2020-11-20 15:12 ` [RFC PATCH 48/76] fscache: Always create /proc/fs/fscache/stats if configured David Howells 2020-11-20 15:13 ` [RFC PATCH 49/76] netfs: Stats David Howells 2020-11-20 15:13 ` [RFC PATCH 50/76] fscache: New stats David Howells 2020-11-20 15:13 ` [RFC PATCH 51/76] fscache, cachefiles: Rewrite invalidation David Howells 2020-11-20 15:13 ` [RFC PATCH 52/76] fscache: disable cookie when doing an invalidation for DIO write David Howells 2020-11-20 15:13 ` [RFC PATCH 53/76] fscache: Implement "will_modify" parameter on fscache_use_cookie() David Howells 2020-11-20 15:14 ` [RFC PATCH 54/76] fscache: Provide resize operation David Howells 2020-11-20 15:14 ` [RFC PATCH 55/76] fscache: Remove the update operation David Howells 2020-11-20 15:14 ` [RFC PATCH 56/76] afs: Pass page into dirty region helpers to provide THP size David Howells 2020-11-20 15:14 ` [RFC PATCH 57/76] afs: Print the operation debug_id when logging an unexpected data version David Howells 2020-11-20 15:14 ` [RFC PATCH 58/76] afs: Move key to afs_read struct David Howells 2020-11-20 15:15 ` [RFC PATCH 59/76] afs: Don't truncate iter during data fetch David Howells 2020-11-20 15:15 ` [RFC PATCH 60/76] afs: Log remote unmarshalling errors David Howells 2020-11-20 15:15 ` [RFC PATCH 61/76] afs: Set up the iov_iter before calling afs_extract_data() David Howells 2020-11-20 15:15 ` [RFC PATCH 62/76] afs: Use ITER_XARRAY for writing David Howells 2020-11-20 15:16 ` [RFC PATCH 63/76] afs: Wait on PG_fscache before modifying/releasing a page David Howells 2020-11-20 15:16 ` [RFC PATCH 64/76] afs: Extract writeback extension into its own function David Howells 2020-11-20 15:16 ` [RFC PATCH 65/76] afs: Prepare for use of THPs David Howells 2020-11-20 15:16 ` [RFC PATCH 66/76] afs: Use the fs operation ops to handle FetchData completion David Howells 2020-11-20 15:17 ` [RFC PATCH 67/76] afs: Use new fscache read helper API David Howells 2020-11-20 15:17 ` [RFC PATCH 68/76] netfs: Add write_begin helper David Howells 2020-11-20 15:17 ` [RFC PATCH 69/76] fscache: Add support for writing to the cache David Howells 2020-11-20 15:17 ` [RFC PATCH 70/76] afs: Use the fscache_write_begin() helper David Howells 2020-11-20 15:18 ` [RFC PATCH 71/76] afs: Copy local writes to the cache when writing to the server David Howells 2020-11-20 15:18 ` [RFC PATCH 72/76] afs: Invoke fscache_resize_cookie() when handling ATTR_SIZE for setattr David Howells 2020-11-20 15:18 ` [RFC PATCH 73/76] afs: Add O_DIRECT read support David Howells 2020-11-20 15:18 ` [RFC PATCH 74/76] afs: Skip truncation on the server of data we haven't written yet David Howells 2020-11-20 15:19 ` [RFC PATCH 75/76] afs: Make afs_write_begin() return the THP subpage David Howells 2020-11-20 15:19 ` [RFC PATCH 76/76] afs: Fix speculative status fetch going out of order wrt to modifications David Howells
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