[23/27] afs: Use netfslib for symlinks, allowing them to be cached

Message ID	20241024140539.3828093-24-dhowells@redhat.com (mailing list archive)
State	New
Headers	show Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 15FD91DFEF for <linux-fsdevel@vger.kernel.org>; Thu, 24 Oct 2024 14:08:53 +0000 (UTC) From: David Howells <dhowells@redhat.com> To: Christian Brauner <christian@brauner.io>, Steve French <smfrench@gmail.com>, Matthew Wilcox <willy@infradead.org> Cc: David Howells <dhowells@redhat.com>, Jeff Layton <jlayton@kernel.org>, Gao Xiang <hsiangkao@linux.alibaba.com>, Dominique Martinet <asmadeus@codewreck.org>, Marc Dionne <marc.dionne@auristor.com>, Paulo Alcantara <pc@manguebit.com>, Shyam Prasad N <sprasad@microsoft.com>, Tom Talpey <tom@talpey.com>, Eric Van Hensbergen <ericvh@kernel.org>, Ilya Dryomov <idryomov@gmail.com>, netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 23/27] afs: Use netfslib for symlinks, allowing them to be cached Date: Thu, 24 Oct 2024 15:05:21 +0100 Message-ID: <20241024140539.3828093-24-dhowells@redhat.com> In-Reply-To: <20241024140539.3828093-1-dhowells@redhat.com> References: <20241024140539.3828093-1-dhowells@redhat.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	netfs: Read performance improvements and "single-blob" support \| expand [00/27] netfs: Read performance improvements and "single-blob" support [01/27] netfs: Remove call to folio_index() [02/27] netfs: Fix a few minor bugs in netfs_page_mkwrite() [03/27] netfs: Remove unnecessary references to pages [04/27] netfs: Use a folio_queue allocation and free functions [05/27] netfs: Add a tracepoint to log the lifespan of folio_queue structs [06/27] netfs: Abstract out a rolling folio buffer implementation [07/27] netfs: Make netfs_advance_write() return size_t [08/27] netfs: Split retry code out of fs/netfs/write_collect.c [09/27] netfs: Drop the error arg from netfs_read_subreq_terminated() [10/27] netfs: Drop the was_async arg from netfs_read_subreq_terminated() [11/27] netfs: Don't use bh spinlock [12/27] afs: Don't use mutex for I/O operation lock [13/27] afs: Fix EEXIST error returned from afs_rmdir() to be ENOTEMPTY [14/27] afs: Fix directory format encoding struct [15/27] netfs: Remove some extraneous directory invalidations [16/27] cachefiles: Add some subrequest tracepoints [17/27] cachefiles: Add auxiliary data trace [18/27] afs: Add more tracepoints to do with tracking validity [19/27] netfs: Add functions to build/clean a buffer in a folio_queue [20/27] netfs: Add support for caching single monolithic objects such as AFS dirs [21/27] afs: Make afs_init_request() get a key if not given a file [22/27] afs: Use netfslib for directories [23/27] afs: Use netfslib for symlinks, allowing them to be cached [24/27] afs: Eliminate afs_read [25/27] afs: Make {Y,}FS.FetchData an asynchronous operation [26/27] netfs: Change the read result collector to only use one work item [27/27] afs: Make afs_mkdir() locally initialise a new directory's content

diff --git a/fs/afs/file.c b/fs/afs/file.c index 5bc36bfaa173..48695a50d2f9 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -20,7 +20,6 @@ #include "internal.h" static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); -static int afs_symlink_read_folio(struct file *file, struct folio *folio); static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter); static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos, @@ -61,13 +60,6 @@ const struct address_space_operations afs_file_aops = { .writepages = afs_writepages, }; -const struct address_space_operations afs_symlink_aops = { - .read_folio = afs_symlink_read_folio, - .release_folio = netfs_release_folio, - .invalidate_folio = netfs_invalidate_folio, - .migrate_folio = filemap_migrate_folio, -}; - static const struct vm_operations_struct afs_vm_ops = { .open = afs_vm_open, .close = afs_vm_close, @@ -346,30 +338,6 @@ static void afs_issue_read(struct netfs_io_subrequest *subreq) queue_work(system_long_wq, &subreq->work); } -static int afs_symlink_read_folio(struct file *file, struct folio *folio) -{ - struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host); - struct afs_read *fsreq; - int ret; - - fsreq = afs_alloc_read(GFP_NOFS); - if (!fsreq) - return -ENOMEM; - - fsreq->pos = folio_pos(folio); - fsreq->len = folio_size(folio); - fsreq->vnode = vnode; - fsreq->iter = &fsreq->def_iter; - iov_iter_xarray(&fsreq->def_iter, ITER_DEST, &folio->mapping->i_pages, - fsreq->pos, fsreq->len); - - ret = afs_fetch_data(fsreq->vnode, fsreq); - if (ret == 0) - folio_mark_uptodate(folio); - folio_unlock(folio); - return ret; -} - static int afs_init_request(struct netfs_io_request *rreq, struct file *file) { struct afs_vnode *vnode = AFS_FS_I(rreq->inode); diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 0ed1e5c35fef..8c7aa759ad1b 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -25,8 +25,58 @@ #include "internal.h" #include "afs_fs.h" +static void afs_put_link(void *arg) +{ + struct folio *folio = virt_to_folio(arg); + + kunmap_local(arg); + folio_put(folio); +} + +const char *afs_get_link(struct dentry *dentry, struct inode *inode, + struct delayed_call *callback) +{ + struct afs_vnode *vnode = AFS_FS_I(inode); + struct folio *folio; + char *content; + ssize_t ret; + + if (atomic64_read(&vnode->cb_expires_at) == AFS_NO_CB_PROMISE || + !vnode->directory) { + ret = afs_read_single(vnode, NULL); + if (ret < 0) + return ERR_PTR(ret); + } + + folio = folioq_folio(vnode->directory, 0); + folio_get(folio); + content = kmap_local_folio(folio, 0); + set_delayed_call(callback, afs_put_link, content); + return content; +} + +int afs_readlink(struct dentry *dentry, char __user *buffer, int buflen) +{ + DEFINE_DELAYED_CALL(done); + const char *content; + int len; + + content = afs_get_link(dentry, d_inode(dentry), &done); + if (IS_ERR(content)) { + do_delayed_call(&done); + return PTR_ERR(content); + } + + len = umin(strlen(content), buflen); + if (copy_to_user(buffer, content, len)) + len = -EFAULT; + do_delayed_call(&done); + return len; +} + static const struct inode_operations afs_symlink_inode_operations = { - .get_link = page_get_link, + .get_link = afs_get_link, + .readlink = afs_readlink, }; static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode) @@ -124,13 +174,13 @@ static int afs_inode_init_from_status(struct afs_operation *op, inode->i_mode = S_IFDIR | 0555; inode->i_op = &afs_mntpt_inode_operations; inode->i_fop = &afs_mntpt_file_operations; - inode->i_mapping->a_ops = &afs_symlink_aops; } else { inode->i_mode = S_IFLNK | status->mode; inode->i_op = &afs_symlink_inode_operations; - inode->i_mapping->a_ops = &afs_symlink_aops; } + inode->i_mapping->a_ops = &afs_dir_aops; inode_nohighmem(inode); + mapping_set_release_always(inode->i_mapping); break; default: dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL); @@ -443,7 +493,8 @@ static void afs_get_inode_cache(struct afs_vnode *vnode) struct afs_vnode_cache_aux aux; if (vnode->status.type != AFS_FTYPE_FILE && - vnode->status.type != AFS_FTYPE_DIR) { + vnode->status.type != AFS_FTYPE_DIR && + vnode->status.type != AFS_FTYPE_SYMLINK) { vnode->netfs.cache = NULL; return; } @@ -657,7 +708,8 @@ void afs_evict_inode(struct inode *inode) ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); - if ((S_ISDIR(inode->i_mode)) && + if ((S_ISDIR(inode->i_mode) || + S_ISLNK(inode->i_mode)) && (inode->i_state & I_DIRTY) && !sbi->dyn_root) { struct writeback_control wbc = { diff --git a/fs/afs/internal.h b/fs/afs/internal.h index ecf5df9ca12c..6fa3b1dd4c98 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -1115,7 +1115,6 @@ extern void afs_dynroot_depopulate(struct super_block *); * file.c */ extern const struct address_space_operations afs_file_aops; -extern const struct address_space_operations afs_symlink_aops; extern const struct inode_operations afs_file_inode_operations; extern const struct file_operations afs_file_operations; extern const struct netfs_request_ops afs_req_ops; @@ -1221,6 +1220,9 @@ extern void afs_fs_probe_cleanup(struct afs_net *); */ extern const struct afs_operation_ops afs_fetch_status_operation; +const char *afs_get_link(struct dentry *dentry, struct inode *inode, + struct delayed_call *callback); +int afs_readlink(struct dentry *dentry, char __user *buffer, int buflen); extern void afs_vnode_commit_status(struct afs_operation *, struct afs_vnode_param *); extern int afs_fetch_status(struct afs_vnode *, struct key *, bool, afs_access_t *); extern int afs_ilookup5_test_by_fid(struct inode *, void *); diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index 297487ee8323..507c25a5b2cb 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -30,7 +30,7 @@ const struct file_operations afs_mntpt_file_operations = { const struct inode_operations afs_mntpt_inode_operations = { .lookup = afs_mntpt_lookup, - .readlink = page_readlink, + .readlink = afs_readlink, .getattr = afs_getattr, }; @@ -118,9 +118,9 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) ctx->volnamesz = sizeof(afs_root_volume) - 1; } else { /* read the contents of the AFS special symlink */ - struct page *page; + DEFINE_DELAYED_CALL(cleanup); + const char *content; loff_t size = i_size_read(d_inode(mntpt)); - char *buf; if (src_as->cell) ctx->cell = afs_use_cell(src_as->cell, afs_cell_trace_use_mntpt); @@ -128,16 +128,16 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) if (size < 2 || size > PAGE_SIZE - 1) return -EINVAL; - page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL); - if (IS_ERR(page)) - return PTR_ERR(page); + content = afs_get_link(mntpt, d_inode(mntpt), &cleanup); + if (IS_ERR(content)) { + do_delayed_call(&cleanup); + return PTR_ERR(content); + } - buf = kmap(page); ret = -EINVAL; - if (buf[size - 1] == '.') - ret = vfs_parse_fs_string(fc, "source", buf, size - 1); - kunmap(page); - put_page(page); + if (content[size - 1] == '.') + ret = vfs_parse_fs_string(fc, "source", content, size - 1); + do_delayed_call(&cleanup); if (ret < 0) return ret; diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index d05f2c09efe3..49a749672e38 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -422,6 +422,7 @@ enum yfs_cm_operation { EM(afs_file_error_dir_over_end, "DIR_ENT_OVER_END") \ EM(afs_file_error_dir_small, "DIR_SMALL") \ EM(afs_file_error_dir_unmarked_ext, "DIR_UNMARKED_EXT") \ + EM(afs_file_error_symlink_big, "SYM_BIG") \ EM(afs_file_error_mntpt, "MNTPT_READ_FAILED") \ E_(afs_file_error_writeback_fail, "WRITEBACK_FAILED")

[23/27] afs: Use netfslib for symlinks, allowing them to be cached

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