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Message-ID: <e32db4ef5a0ae4e2002a3d957491c88e49daa5bb.camel@kernel.org>
Date: Tue, 07 Apr 2020 18:57:50 -0400
From: Jeff Layton <jlayton@...nel.org>
To: Luis Henriques <lhenriques@...e.com>, Sage Weil <sage@...hat.com>,
Ilya Dryomov <idryomov@...il.com>,
Gregory Farnum <gfarnum@...hat.com>,
Zheng Yan <zyan@...hat.com>
Cc: Frank Schilder <frans@....dk>, ceph-devel@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] ceph: allow rename operation under different
quota realms
On Tue, 2020-04-07 at 11:30 +0100, Luis Henriques wrote:
> Returning -EXDEV when trying to 'mv' files/directories from different
> quota realms results in copy+unlink operations instead of the faster
> CEPH_MDS_OP_RENAME. This will occur even when there aren't any quotas
> set in the destination directory, or if there's enough space left for
> the new file(s).
>
> This patch adds a new helper function to be called on rename operations
> which will allow these operations if they can be executed. This patch
> mimics userland fuse client commit b8954e5734b3 ("client:
> optimize rename operation under different quota root").
>
> Since ceph_quota_is_same_realm() is now called only from this new
> helper, make it static.
>
> URL: https://tracker.ceph.com/issues/44791
> Signed-off-by: Luis Henriques <lhenriques@...e.com>
> ---
> fs/ceph/dir.c | 9 ++++----
> fs/ceph/quota.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++-
> fs/ceph/super.h | 3 ++-
> 3 files changed, 64 insertions(+), 6 deletions(-)
>
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index d0cd0aba5843..23f0345611a3 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -1099,11 +1099,12 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
> op = CEPH_MDS_OP_RENAMESNAP;
> else
> return -EROFS;
> + } else if (old_dir != new_dir) {
> + err = ceph_quota_check_rename(mdsc, d_inode(old_dentry),
> + new_dir);
> + if (err)
> + return err;
> }
> - /* don't allow cross-quota renames */
> - if ((old_dir != new_dir) &&
> - (!ceph_quota_is_same_realm(old_dir, new_dir)))
> - return -EXDEV;
>
> dout("rename dir %p dentry %p to dir %p dentry %p\n",
> old_dir, old_dentry, new_dir, new_dentry);
> diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
> index c5c8050f0f99..9e82704a9f7b 100644
> --- a/fs/ceph/quota.c
> +++ b/fs/ceph/quota.c
> @@ -264,7 +264,7 @@ static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc,
> return NULL;
> }
>
> -bool ceph_quota_is_same_realm(struct inode *old, struct inode *new)
> +static bool ceph_quota_is_same_realm(struct inode *old, struct inode *new)
> {
> struct ceph_mds_client *mdsc = ceph_inode_to_client(old)->mdsc;
> struct ceph_snap_realm *old_realm, *new_realm;
> @@ -516,3 +516,59 @@ bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf)
> return is_updated;
> }
>
> +/*
> + * ceph_quota_check_rename - check if a rename can be executed
> + * @mdsc: MDS client instance
> + * @old: inode to be copied
> + * @new: destination inode (directory)
> + *
> + * This function verifies if a rename (e.g. moving a file or directory) can be
> + * executed. It forces an rstat update in the @new target directory (and in the
> + * source @old as well, if it's a directory). The actual check is done both for
> + * max_files and max_bytes.
> + *
> + * This function returns 0 if it's OK to do the rename, or, if quotas are
> + * exceeded, -EXDEV (if @old is a directory) or -EDQUOT.
> + */
> +int ceph_quota_check_rename(struct ceph_mds_client *mdsc,
> + struct inode *old, struct inode *new)
> +{
> + struct ceph_inode_info *ci_old = ceph_inode(old);
> + int ret = 0;
> +
> + if (ceph_quota_is_same_realm(old, new))
> + return 0;
> +
> + /*
> + * Get the latest rstat for target directory (and for source, if a
> + * directory)
> + */
> + ret = ceph_do_getattr(new, CEPH_STAT_RSTAT, false);
> + if (ret)
> + return ret;
> +
> + if (S_ISDIR(old->i_mode)) {
> + ret = ceph_do_getattr(old, CEPH_STAT_RSTAT, false);
> + if (ret)
> + return ret;
> + ret = check_quota_exceeded(new, QUOTA_CHECK_MAX_BYTES_OP,
> + ci_old->i_rbytes);
> + if (!ret)
> + ret = check_quota_exceeded(new,
> + QUOTA_CHECK_MAX_FILES_OP,
> + ci_old->i_rfiles +
> + ci_old->i_rsubdirs);
Somewhat idle curiosity, but what happens with hardlinked files where
one dentry is in one quota domain and another is in a different one?
Does it stay in the old quotarealm?
In any case, this is likely fine as non-hardlinked files are the
pessimal case anyway.
> + if (ret)
> + ret = -EXDEV;
> + } else {
> + ret = check_quota_exceeded(new, QUOTA_CHECK_MAX_BYTES_OP,
> + i_size_read(old));
> + if (!ret)
> + ret = check_quota_exceeded(new,
> + QUOTA_CHECK_MAX_FILES_OP, 1);
> + if (ret)
> + ret = -EDQUOT;
> + }
> +
> + return ret;
> +}
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 037cdfb2ad4f..d5853831a6b5 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -1175,13 +1175,14 @@ extern void ceph_handle_quota(struct ceph_mds_client *mdsc,
> struct ceph_mds_session *session,
> struct ceph_msg *msg);
> extern bool ceph_quota_is_max_files_exceeded(struct inode *inode);
> -extern bool ceph_quota_is_same_realm(struct inode *old, struct inode *new);
> extern bool ceph_quota_is_max_bytes_exceeded(struct inode *inode,
> loff_t newlen);
> extern bool ceph_quota_is_max_bytes_approaching(struct inode *inode,
> loff_t newlen);
> extern bool ceph_quota_update_statfs(struct ceph_fs_client *fsc,
> struct kstatfs *buf);
> +extern int ceph_quota_check_rename(struct ceph_mds_client *mdsc,
> + struct inode *old, struct inode *new);
> extern void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc);
>
> #endif /* _FS_CEPH_SUPER_H */
--
Jeff Layton <jlayton@...nel.org>
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