| Message ID | 20190430112236.14162-2-jlayton@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] ceph: use ceph_mdsc_build_path instead of clone_dentry_name | expand |
On Tue, 2019-04-30 at 07:22 -0400, Jeff Layton wrote: > While it may be slightly more efficient, it's probably not worthwhile to > optimize for the case that clone_dentry_name handles. We can get the > same result by just calling ceph_mdsc_build_path when the parent isn't > locked, with less code duplication. > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > --- > fs/ceph/mds_client.c | 41 +++-------------------------------------- > 1 file changed, 3 insertions(+), 38 deletions(-) > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index 74cb3078ea63..e8245df09691 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -2170,55 +2170,20 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > return path; > } > > -/* Duplicate the dentry->d_name.name safely */ > -static int clone_dentry_name(struct dentry *dentry, const char **ppath, > - int *ppathlen) > -{ > - u32 len; > - char *name; > -retry: > - len = READ_ONCE(dentry->d_name.len); > - name = kmalloc(len + 1, GFP_NOFS); > - if (!name) > - return -ENOMEM; > - > - spin_lock(&dentry->d_lock); > - if (dentry->d_name.len != len) { > - spin_unlock(&dentry->d_lock); > - kfree(name); > - goto retry; > - } > - memcpy(name, dentry->d_name.name, len); > - spin_unlock(&dentry->d_lock); > - > - name[len] = '\0'; > - *ppath = name; > - *ppathlen = len; > - return 0; > -} > - > static int build_dentry_path(struct dentry *dentry, struct inode *dir, > const char **ppath, int *ppathlen, u64 *pino, > bool *pfreepath, bool parent_locked) > { > - int ret; > char *path; > > rcu_read_lock(); > if (!dir) > dir = d_inode_rcu(dentry->d_parent); > - if (dir && ceph_snap(dir) == CEPH_NOSNAP) { > + if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) { > *pino = ceph_ino(dir); > rcu_read_unlock(); > - if (parent_locked) { > - *ppath = dentry->d_name.name; > - *ppathlen = dentry->d_name.len; > - } else { > - ret = clone_dentry_name(dentry, ppath, ppathlen); > - if (ret) > - return ret; > - *pfreepath = true; > - } > + *ppath = dentry->d_name.name; > + *ppathlen = dentry->d_name.len; > return 0; > } > rcu_read_unlock(); Please ignore this patch -- bad git-send-email command on my part. Sorry!
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 74cb3078ea63..e8245df09691 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -2170,55 +2170,20 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, return path; } -/* Duplicate the dentry->d_name.name safely */ -static int clone_dentry_name(struct dentry *dentry, const char **ppath, - int *ppathlen) -{ - u32 len; - char *name; -retry: - len = READ_ONCE(dentry->d_name.len); - name = kmalloc(len + 1, GFP_NOFS); - if (!name) - return -ENOMEM; - - spin_lock(&dentry->d_lock); - if (dentry->d_name.len != len) { - spin_unlock(&dentry->d_lock); - kfree(name); - goto retry; - } - memcpy(name, dentry->d_name.name, len); - spin_unlock(&dentry->d_lock); - - name[len] = '\0'; - *ppath = name; - *ppathlen = len; - return 0; -} - static int build_dentry_path(struct dentry *dentry, struct inode *dir, const char **ppath, int *ppathlen, u64 *pino, bool *pfreepath, bool parent_locked) { - int ret; char *path; rcu_read_lock(); if (!dir) dir = d_inode_rcu(dentry->d_parent); - if (dir && ceph_snap(dir) == CEPH_NOSNAP) { + if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) { *pino = ceph_ino(dir); rcu_read_unlock(); - if (parent_locked) { - *ppath = dentry->d_name.name; - *ppathlen = dentry->d_name.len; - } else { - ret = clone_dentry_name(dentry, ppath, ppathlen); - if (ret) - return ret; - *pfreepath = true; - } + *ppath = dentry->d_name.name; + *ppathlen = dentry->d_name.len; return 0; } rcu_read_unlock();
While it may be slightly more efficient, it's probably not worthwhile to optimize for the case that clone_dentry_name handles. We can get the same result by just calling ceph_mdsc_build_path when the parent isn't locked, with less code duplication. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/ceph/mds_client.c | 41 +++-------------------------------------- 1 file changed, 3 insertions(+), 38 deletions(-)