From: David Howells <dhowells@redhat.com>
To: linux-cachefs@redhat.com
Cc: dhowells@redhat.com, Trond Myklebust <trondmy@hammerspace.com>,
Anna Schumaker <anna.schumaker@netapp.com>,
Steve French <sfrench@samba.org>,
Dominique Martinet <asmadeus@codewreck.org>,
Jeff Layton <jlayton@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Omar Sandoval <osandov@osandov.com>,
JeffleXu <jefflexu@linux.alibaba.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
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: [PATCH v3 39/68] cachefiles: Implement a function to get/create a directory in the cache
Date: Thu, 16 Dec 2021 16:16:59 +0000 [thread overview]
Message-ID: <163967141952.1823006.7832985646370603833.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <163967073889.1823006.12237147297060239168.stgit@warthog.procyon.org.uk>
Implement a function to get/create structural directories in the cache.
This is used for setting up a cache and creating volume substructures. The
directory in memory are marked with the S_KERNEL_FILE inode flag whilst
they're in use to tell rmdir to reject attempts to remove them.
Changes
=======
ver #3:
- Return an indication as to whether the directory was freshly created.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819631182.215744.3322471539523262619.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906933130.143852.962088616746509062.stgit@warthog.procyon.org.uk/ # v2
---
fs/cachefiles/internal.h | 9 +++
fs/cachefiles/namei.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 150 insertions(+)
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 3783a3e01027..48768a3ab105 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -125,6 +125,15 @@ static inline int cachefiles_inject_remove_error(void)
return cachefiles_error_injection_state & 2 ? -EIO : 0;
}
+/*
+ * namei.c
+ */
+extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
+ struct dentry *dir,
+ const char *name,
+ bool *_is_new);
+extern void cachefiles_put_directory(struct dentry *dir);
+
/*
* security.c
*/
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 913f83f1c900..11a33209ab5f 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -6,6 +6,7 @@
*/
#include <linux/fs.h>
+#include <linux/namei.h>
#include "internal.h"
/*
@@ -41,3 +42,143 @@ static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
inode->i_flags &= ~S_KERNEL_FILE;
trace_cachefiles_mark_inactive(object, inode);
}
+
+/*
+ * get a subdirectory
+ */
+struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
+ struct dentry *dir,
+ const char *dirname,
+ bool *_is_new)
+{
+ struct dentry *subdir;
+ struct path path;
+ int ret;
+
+ _enter(",,%s", dirname);
+
+ /* search the current directory for the element name */
+ inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
+
+retry:
+ ret = cachefiles_inject_read_error();
+ if (ret == 0)
+ subdir = lookup_one_len(dirname, dir, strlen(dirname));
+ else
+ subdir = ERR_PTR(ret);
+ if (IS_ERR(subdir)) {
+ trace_cachefiles_vfs_error(NULL, d_backing_inode(dir),
+ PTR_ERR(subdir),
+ cachefiles_trace_lookup_error);
+ if (PTR_ERR(subdir) == -ENOMEM)
+ goto nomem_d_alloc;
+ goto lookup_error;
+ }
+
+ _debug("subdir -> %pd %s",
+ subdir, d_backing_inode(subdir) ? "positive" : "negative");
+
+ /* we need to create the subdir if it doesn't exist yet */
+ if (d_is_negative(subdir)) {
+ ret = cachefiles_has_space(cache, 1, 0);
+ if (ret < 0)
+ goto mkdir_error;
+
+ _debug("attempt mkdir");
+
+ path.mnt = cache->mnt;
+ path.dentry = dir;
+ ret = security_path_mkdir(&path, subdir, 0700);
+ if (ret < 0)
+ goto mkdir_error;
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_mkdir(&init_user_ns, d_inode(dir), subdir, 0700);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(NULL, d_inode(dir), ret,
+ cachefiles_trace_mkdir_error);
+ goto mkdir_error;
+ }
+
+ if (unlikely(d_unhashed(subdir))) {
+ cachefiles_put_directory(subdir);
+ goto retry;
+ }
+ ASSERT(d_backing_inode(subdir));
+
+ _debug("mkdir -> %pd{ino=%lu}",
+ subdir, d_backing_inode(subdir)->i_ino);
+ if (_is_new)
+ *_is_new = true;
+ }
+
+ /* Tell rmdir() it's not allowed to delete the subdir */
+ inode_lock(d_inode(subdir));
+ inode_unlock(d_inode(dir));
+
+ if (!__cachefiles_mark_inode_in_use(NULL, subdir))
+ goto mark_error;
+
+ inode_unlock(d_inode(subdir));
+
+ /* we need to make sure the subdir is a directory */
+ ASSERT(d_backing_inode(subdir));
+
+ if (!d_can_lookup(subdir)) {
+ pr_err("%s is not a directory\n", dirname);
+ ret = -EIO;
+ goto check_error;
+ }
+
+ ret = -EPERM;
+ if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) ||
+ !d_backing_inode(subdir)->i_op->lookup ||
+ !d_backing_inode(subdir)->i_op->mkdir ||
+ !d_backing_inode(subdir)->i_op->rename ||
+ !d_backing_inode(subdir)->i_op->rmdir ||
+ !d_backing_inode(subdir)->i_op->unlink)
+ goto check_error;
+
+ _leave(" = [%lu]", d_backing_inode(subdir)->i_ino);
+ return subdir;
+
+check_error:
+ cachefiles_put_directory(subdir);
+ _leave(" = %d [check]", ret);
+ return ERR_PTR(ret);
+
+mark_error:
+ inode_unlock(d_inode(subdir));
+ dput(subdir);
+ return ERR_PTR(-EBUSY);
+
+mkdir_error:
+ inode_unlock(d_inode(dir));
+ dput(subdir);
+ pr_err("mkdir %s failed with error %d\n", dirname, ret);
+ return ERR_PTR(ret);
+
+lookup_error:
+ inode_unlock(d_inode(dir));
+ ret = PTR_ERR(subdir);
+ pr_err("Lookup %s failed with error %d\n", dirname, ret);
+ return ERR_PTR(ret);
+
+nomem_d_alloc:
+ inode_unlock(d_inode(dir));
+ _leave(" = -ENOMEM");
+ return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Put a subdirectory.
+ */
+void cachefiles_put_directory(struct dentry *dir)
+{
+ if (dir) {
+ inode_lock(dir->d_inode);
+ __cachefiles_unmark_inode_in_use(NULL, dir);
+ inode_unlock(dir->d_inode);
+ dput(dir);
+ }
+}
next prev parent reply other threads:[~2021-12-16 16:17 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-16 16:05 [PATCH v3 00/68] fscache, cachefiles: Rewrite David Howells
2021-12-16 16:05 ` [PATCH v3 01/68] fscache, cachefiles: Disable configuration David Howells
2021-12-16 16:06 ` [PATCH v3 02/68] cachefiles: Delete the cachefiles driver pending rewrite David Howells
2021-12-16 16:06 ` [PATCH v3 03/68] fscache: Remove the contents of the fscache driver, " David Howells
2021-12-16 16:06 ` [PATCH v3 04/68] netfs: Display the netfs inode number in the netfs_read tracepoint David Howells
2021-12-16 16:06 ` [PATCH v3 05/68] netfs: Pass a flag to ->prepare_write() to say if there's no alloc'd space David Howells
2021-12-16 16:06 ` [PATCH v3 06/68] fscache: Introduce new driver David Howells
2021-12-16 16:07 ` [PATCH v3 07/68] fscache: Implement a hash function David Howells
2021-12-16 16:07 ` [PATCH v3 08/68] fscache: Implement cache registration David Howells
2021-12-16 16:07 ` [PATCH v3 09/68] fscache: Implement volume registration David Howells
2021-12-16 16:08 ` [PATCH v3 10/68] fscache: Implement cookie registration David Howells
2021-12-16 16:08 ` [PATCH v3 11/68] fscache: Implement cache-level access helpers David Howells
2021-12-16 16:09 ` [PATCH v3 12/68] fscache: Implement volume-level " David Howells
2021-12-16 16:09 ` [PATCH v3 13/68] fscache: Implement cookie-level " David Howells
2021-12-16 16:09 ` [PATCH v3 14/68] fscache: Implement functions add/remove a cache David Howells
2021-12-16 16:09 ` [PATCH v3 15/68] fscache: Provide and use cache methods to lookup/create/free a volume David Howells
2021-12-16 16:10 ` [PATCH v3 16/68] fscache: Add a function for a cache backend to note an I/O error David Howells
2021-12-16 16:10 ` [PATCH v3 17/68] fscache: Implement simple cookie state machine David Howells
2021-12-17 19:07 ` Jeff Layton
2021-12-17 19:45 ` David Howells
2021-12-16 16:11 ` [PATCH v3 18/68] fscache: Implement cookie user counting and resource pinning David Howells
2021-12-17 19:42 ` Jeff Layton
2021-12-17 20:43 ` David Howells
2021-12-16 16:11 ` [PATCH v3 19/68] fscache: Implement cookie invalidation David Howells
2021-12-16 16:11 ` [PATCH v3 20/68] fscache: Provide a means to begin an operation David Howells
2021-12-16 16:11 ` [PATCH v3 21/68] fscache: Count data storage objects in a cache David Howells
2021-12-16 16:12 ` [PATCH v3 22/68] fscache: Provide read/write stat counters for the cache David Howells
2021-12-16 16:12 ` [PATCH v3 23/68] fscache: Provide a function to let the netfs update its coherency data David Howells
2021-12-16 16:13 ` [PATCH v3 24/68] netfs: Pass more information on how to deal with a hole in the cache David Howells
2021-12-16 16:13 ` [PATCH v3 25/68] fscache: Implement raw I/O interface David Howells
2021-12-16 16:13 ` [PATCH v3 26/68] fscache: Implement higher-level write " David Howells
2021-12-16 16:14 ` [PATCH v3 27/68] vfs, fscache: Implement pinning of cache usage for writeback David Howells
2021-12-16 16:14 ` [PATCH v3 28/68] fscache: Provide a function to note the release of a page David Howells
2021-12-16 16:14 ` [PATCH v3 29/68] fscache: Provide a function to resize a cookie David Howells
2021-12-16 16:15 ` [PATCH v3 30/68] cachefiles: Introduce rewritten driver David Howells
2021-12-16 16:15 ` [PATCH v3 31/68] cachefiles: Define structs David Howells
2021-12-16 16:15 ` [PATCH v3 32/68] cachefiles: Add some error injection support David Howells
2021-12-16 16:15 ` [PATCH v3 33/68] cachefiles: Add a couple of tracepoints for logging errors David Howells
2021-12-16 16:16 ` [PATCH v3 34/68] cachefiles: Add cache error reporting macro David Howells
2021-12-16 16:16 ` [PATCH v3 35/68] cachefiles: Add security derivation David Howells
2021-12-16 16:16 ` [PATCH v3 36/68] cachefiles: Register a miscdev and parse commands over it David Howells
2021-12-16 16:16 ` [PATCH v3 37/68] cachefiles: Provide a function to check how much space there is David Howells
2021-12-16 16:16 ` [PATCH v3 38/68] vfs, cachefiles: Mark a backing file in use with an inode flag David Howells
2021-12-16 16:16 ` David Howells [this message]
2021-12-16 16:17 ` [PATCH v3 40/68] cachefiles: Implement cache registration and withdrawal David Howells
2021-12-16 16:17 ` [PATCH v3 41/68] cachefiles: Implement volume support David Howells
2021-12-16 16:17 ` [PATCH v3 42/68] cachefiles: Add tracepoints for calls to the VFS David Howells
2021-12-16 16:18 ` [PATCH v3 43/68] cachefiles: Implement object lifecycle funcs David Howells
2021-12-16 16:18 ` [PATCH v3 44/68] cachefiles: Implement key to filename encoding David Howells
2021-12-16 16:18 ` [PATCH v3 45/68] cachefiles: Implement metadata/coherency data storage in xattrs David Howells
2021-12-16 16:19 ` [PATCH v3 46/68] cachefiles: Mark a backing file in use with an inode flag David Howells
2021-12-16 16:19 ` [PATCH v3 47/68] cachefiles: Implement culling daemon commands David Howells
2021-12-16 16:19 ` [PATCH v3 48/68] cachefiles: Implement backing file wrangling David Howells
2021-12-16 16:20 ` [PATCH v3 49/68] cachefiles: Implement begin and end I/O operation David Howells
2021-12-16 16:20 ` [PATCH v3 50/68] cachefiles: Implement cookie resize for truncate David Howells
2021-12-16 16:20 ` [PATCH v3 51/68] cachefiles: Implement the I/O routines David Howells
2021-12-16 16:20 ` [PATCH v3 52/68] fscache, cachefiles: Store the volume coherency data David Howells
2021-12-16 16:20 ` [PATCH v3 53/68] cachefiles: Allow cachefiles to actually function David Howells
2021-12-16 16:21 ` [PATCH v3 54/68] fscache, cachefiles: Display stats of no-space events David Howells
2021-12-16 16:21 ` [PATCH v3 55/68] fscache, cachefiles: Display stat of culling events David Howells
2021-12-16 16:21 ` [PATCH v3 56/68] afs: Handle len being extending over page end in write_begin/write_end David Howells
2021-12-16 16:31 ` Linus Torvalds
2021-12-16 19:28 ` Matthew Wilcox
2021-12-16 19:46 ` Linus Torvalds
2021-12-16 20:20 ` Matthew Wilcox
2021-12-16 21:17 ` David Howells
2021-12-16 16:47 ` David Howells
2021-12-16 16:22 ` [PATCH v3 57/68] afs: Fix afs_write_end() to handle len > page size David Howells
2021-12-16 16:27 ` Linus Torvalds
2021-12-16 16:22 ` [PATCH v3 58/68] afs: Convert afs to use the new fscache API David Howells
2021-12-16 16:22 ` [PATCH v3 59/68] afs: Copy local writes to the cache when writing to the server David Howells
2021-12-16 16:22 ` [PATCH v3 60/68] afs: Skip truncation on the server of data we haven't written yet David Howells
2021-12-16 16:23 ` [PATCH v3 61/68] 9p: Use fscache indexing rewrite and reenable caching David Howells
2021-12-16 16:23 ` [PATCH v3 62/68] 9p: Copy local writes to the cache when writing to the server David Howells
2021-12-16 16:23 ` [PATCH v3 63/68] nfs: Convert to new fscache volume/cookie API David Howells
2021-12-17 12:53 ` David Wysochanski
2021-12-17 13:21 ` David Howells
2021-12-17 13:35 ` David Wysochanski
2021-12-16 16:24 ` [PATCH v3 64/68] nfs: Implement cache I/O by accessing the cache directly David Howells
2021-12-16 16:24 ` [PATCH v3 65/68] cifs: Support fscache indexing rewrite (untested) David Howells
2021-12-16 16:24 ` [PATCH v3 66/68] ceph: conversion to new fscache API David Howells
2021-12-16 16:25 ` [PATCH v3 67/68] ceph: add fscache writeback support David Howells
2021-12-16 16:25 ` [PATCH v3 68/68] fscache: Rewrite documentation David Howells
2021-12-17 20:13 ` [PATCH v3 00/68] fscache, cachefiles: Rewrite Jeff Layton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=163967141952.1823006.7832985646370603833.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=anna.schumaker@netapp.com \
--cc=asmadeus@codewreck.org \
--cc=ceph-devel@vger.kernel.org \
--cc=jefflexu@linux.alibaba.com \
--cc=jlayton@kernel.org \
--cc=linux-afs@lists.infradead.org \
--cc=linux-cachefs@redhat.com \
--cc=linux-cifs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=osandov@osandov.com \
--cc=sfrench@samba.org \
--cc=torvalds@linux-foundation.org \
--cc=trondmy@hammerspace.com \
--cc=v9fs-developer@lists.sourceforge.net \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).