From: Jeff Layton <jlayton@kernel.org>
To: ceph-devel@vger.kernel.org
Cc: xiubli@redhat.com, idryomov@gmail.com, lhenriques@suse.de,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v12 16/54] ceph: make ceph_msdc_build_path use ref-walk
Date: Thu, 31 Mar 2022 11:30:52 -0400 [thread overview]
Message-ID: <20220331153130.41287-17-jlayton@kernel.org> (raw)
In-Reply-To: <20220331153130.41287-1-jlayton@kernel.org>
Encryption potentially requires allocation, at which point we'll need to
be in a non-atomic context. Convert ceph_msdc_build_path to take dentry
spinlocks and references instead of using rcu_read_lock to walk the
path.
This is slightly less efficient, and we may want to eventually allow
using RCU when the leaf dentry isn't encrypted.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/mds_client.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 2f2f8221eb25..28315053e116 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2398,7 +2398,8 @@ static inline u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
int stop_on_nosnap)
{
- struct dentry *temp;
+ struct dentry *cur;
+ struct inode *inode;
char *path;
int pos;
unsigned seq;
@@ -2415,34 +2416,35 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
path[pos] = '\0';
seq = read_seqbegin(&rename_lock);
- rcu_read_lock();
- temp = dentry;
+ cur = dget(dentry);
for (;;) {
- struct inode *inode;
+ struct dentry *temp;
- spin_lock(&temp->d_lock);
- inode = d_inode(temp);
+ spin_lock(&cur->d_lock);
+ inode = d_inode(cur);
if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
dout("build_path path+%d: %p SNAPDIR\n",
- pos, temp);
- } else if (stop_on_nosnap && inode && dentry != temp &&
+ pos, cur);
+ } else if (stop_on_nosnap && inode && dentry != cur &&
ceph_snap(inode) == CEPH_NOSNAP) {
- spin_unlock(&temp->d_lock);
+ spin_unlock(&cur->d_lock);
pos++; /* get rid of any prepended '/' */
break;
} else {
- pos -= temp->d_name.len;
+ pos -= cur->d_name.len;
if (pos < 0) {
- spin_unlock(&temp->d_lock);
+ spin_unlock(&cur->d_lock);
break;
}
- memcpy(path + pos, temp->d_name.name, temp->d_name.len);
+ memcpy(path + pos, cur->d_name.name, cur->d_name.len);
}
+ temp = cur;
spin_unlock(&temp->d_lock);
- temp = READ_ONCE(temp->d_parent);
+ cur = dget_parent(temp);
+ dput(temp);
/* Are we at the root? */
- if (IS_ROOT(temp))
+ if (IS_ROOT(cur))
break;
/* Are we out of buffer? */
@@ -2451,8 +2453,9 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
path[pos] = '/';
}
- base = ceph_ino(d_inode(temp));
- rcu_read_unlock();
+ inode = d_inode(cur);
+ base = inode ? ceph_ino(inode) : 0;
+ dput(cur);
if (read_seqretry(&rename_lock, seq))
goto retry;
--
2.35.1
next prev parent reply other threads:[~2022-03-31 15:33 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-31 15:30 [PATCH v12 00/54] ceph+fscrypt: fully-working prototype Jeff Layton
2022-03-31 15:30 ` [PATCH v12 01/54] vfs: export new_inode_pseudo Jeff Layton
2022-03-31 19:50 ` Al Viro
2022-03-31 22:23 ` Jeff Layton
2022-03-31 15:30 ` [PATCH v12 02/54] fscrypt: export fscrypt_base64url_encode and fscrypt_base64url_decode Jeff Layton
2022-03-31 15:30 ` [PATCH v12 03/54] fscrypt: export fscrypt_fname_encrypt and fscrypt_fname_encrypted_size Jeff Layton
2022-03-31 15:30 ` [PATCH v12 04/54] fscrypt: add fscrypt_context_for_new_inode Jeff Layton
2022-03-31 15:30 ` [PATCH v12 05/54] ceph: preallocate inode for ops that may create one Jeff Layton
2022-03-31 15:30 ` [PATCH v12 06/54] ceph: crypto context handling for ceph Jeff Layton
2022-03-31 15:30 ` [PATCH v12 07/54] ceph: support legacy v1 encryption policy keysetup Jeff Layton
2022-03-31 20:16 ` Eric Biggers
2022-04-01 10:22 ` Luís Henriques
2022-03-31 15:30 ` [PATCH v12 08/54] ceph: add a has_stable_inodes operation for ceph Jeff Layton
2022-03-31 20:03 ` Eric Biggers
2022-04-01 10:37 ` Jeff Layton
2022-04-01 18:16 ` Eric Biggers
2022-04-01 18:51 ` Jeff Layton
2022-03-31 15:30 ` [PATCH v12 09/54] ceph: ensure that we accept a new context from MDS for new inodes Jeff Layton
2022-03-31 15:30 ` [PATCH v12 10/54] ceph: add support for fscrypt_auth/fscrypt_file to cap messages Jeff Layton
2022-03-31 15:30 ` [PATCH v12 11/54] ceph: add ability to set fscrypt_auth via setattr Jeff Layton
2022-03-31 15:30 ` [PATCH v12 12/54] ceph: implement -o test_dummy_encryption mount option Jeff Layton
2022-03-31 15:30 ` [PATCH v12 13/54] ceph: decode alternate_name in lease info Jeff Layton
2022-03-31 15:30 ` [PATCH v12 14/54] ceph: add fscrypt ioctls Jeff Layton
2022-03-31 15:30 ` [PATCH v12 15/54] ceph: make the ioctl cmd more readable in debug log Jeff Layton
2022-03-31 15:30 ` Jeff Layton [this message]
2022-03-31 15:30 ` [PATCH v12 17/54] ceph: add encrypted fname handling to ceph_mdsc_build_path Jeff Layton
2022-03-31 15:30 ` [PATCH v12 18/54] ceph: send altname in MClientRequest Jeff Layton
2022-03-31 15:30 ` [PATCH v12 19/54] ceph: encode encrypted name in dentry release Jeff Layton
2022-03-31 15:30 ` [PATCH v12 20/54] ceph: properly set DCACHE_NOKEY_NAME flag in lookup Jeff Layton
2022-03-31 15:30 ` [PATCH v12 21/54] ceph: set DCACHE_NOKEY_NAME in atomic open Jeff Layton
2022-03-31 15:30 ` [PATCH v12 22/54] ceph: make d_revalidate call fscrypt revalidator for encrypted dentries Jeff Layton
2022-03-31 15:30 ` [PATCH v12 23/54] ceph: add helpers for converting names for userland presentation Jeff Layton
2022-03-31 15:31 ` [PATCH v12 24/54] ceph: fix base64 encoded name's length check in ceph_fname_to_usr() Jeff Layton
2022-03-31 15:31 ` [PATCH v12 25/54] ceph: add fscrypt support to ceph_fill_trace Jeff Layton
2022-03-31 15:31 ` [PATCH v12 26/54] ceph: pass the request to parse_reply_info_readdir() Jeff Layton
2022-03-31 15:31 ` [PATCH v12 27/54] ceph: add ceph_encode_encrypted_dname() helper Jeff Layton
2022-03-31 15:31 ` [PATCH v12 28/54] ceph: add support to readdir for encrypted filenames Jeff Layton
2022-03-31 15:31 ` [PATCH v12 29/54] ceph: create symlinks with encrypted and base64-encoded targets Jeff Layton
2022-03-31 15:31 ` [PATCH v12 30/54] ceph: make ceph_get_name decrypt filenames Jeff Layton
2022-03-31 15:31 ` [PATCH v12 31/54] ceph: add a new ceph.fscrypt.auth vxattr Jeff Layton
2022-03-31 15:31 ` [PATCH v12 32/54] ceph: add some fscrypt guardrails Jeff Layton
2022-03-31 15:31 ` [PATCH v12 33/54] ceph: don't allow changing layout on encrypted files/directories Jeff Layton
2022-03-31 15:31 ` [PATCH v12 34/54] libceph: add CEPH_OSD_OP_ASSERT_VER support Jeff Layton
2022-03-31 15:31 ` [PATCH v12 35/54] ceph: size handling for encrypted inodes in cap updates Jeff Layton
2022-03-31 15:31 ` [PATCH v12 36/54] ceph: fscrypt_file field handling in MClientRequest messages Jeff Layton
2022-03-31 15:31 ` [PATCH v12 37/54] ceph: get file size from fscrypt_file when present in inode traces Jeff Layton
2022-03-31 15:31 ` [PATCH v12 38/54] ceph: handle fscrypt fields in cap messages from MDS Jeff Layton
2022-03-31 15:31 ` [PATCH v12 39/54] ceph: add __ceph_get_caps helper support Jeff Layton
2022-03-31 15:31 ` [PATCH v12 40/54] ceph: add __ceph_sync_read " Jeff Layton
2022-03-31 15:31 ` [PATCH v12 41/54] ceph: add object version support for sync read Jeff Layton
2022-03-31 15:31 ` [PATCH v12 42/54] ceph: add infrastructure for file encryption and decryption Jeff Layton
2022-03-31 15:31 ` [PATCH v12 43/54] ceph: add truncate size handling support for fscrypt Jeff Layton
2022-03-31 15:31 ` [PATCH v12 44/54] libceph: allow ceph_osdc_new_request to accept a multi-op read Jeff Layton
2022-03-31 15:31 ` [PATCH v12 45/54] ceph: disable fallocate for encrypted inodes Jeff Layton
2022-03-31 15:31 ` [PATCH v12 46/54] ceph: disable copy offload on " Jeff Layton
2022-03-31 15:31 ` [PATCH v12 47/54] ceph: don't use special DIO path for " Jeff Layton
2022-03-31 15:31 ` [PATCH v12 48/54] ceph: align data in pages in ceph_sync_write Jeff Layton
2022-03-31 15:31 ` [PATCH v12 49/54] ceph: add read/modify/write to ceph_sync_write Jeff Layton
2022-03-31 15:31 ` [PATCH v12 50/54] ceph: plumb in decryption during sync reads Jeff Layton
2022-03-31 15:31 ` [PATCH v12 51/54] ceph: add fscrypt decryption support to ceph_netfs_issue_op Jeff Layton
2022-03-31 15:31 ` [PATCH v12 52/54] ceph: set i_blkbits to crypto block size for encrypted inodes Jeff Layton
2022-03-31 15:31 ` [PATCH v12 53/54] ceph: add encryption support to writepage Jeff Layton
2022-03-31 15:31 ` [PATCH v12 54/54] ceph: fscrypt support for writepages Jeff Layton
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