From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Vivek Goyal Subject: [PATCH v13 16/28] ovl: Create locked version of ovl_nlink_start() and ovl_nlink_end() Date: Thu, 29 Mar 2018 15:38:42 -0400 Message-Id: <20180329193854.13814-17-vgoyal@redhat.com> In-Reply-To: <20180329193854.13814-1-vgoyal@redhat.com> References: <20180329193854.13814-1-vgoyal@redhat.com> To: linux-unionfs@vger.kernel.org Cc: miklos@szeredi.hu, amir73il@gmail.com, vgoyal@redhat.com List-ID: Soon in ovl_rename() I will introduce a function to take lock both on old and new ovl_inode. That means I don't want ovl_nlink_start() to take lock and ovl_nlink_end() to drop lock. It will be done by other functions. So create ovl_nlink_start_locked() and ovl_nlink_end_locked() which assume that by the time they are called, lock has already been taken and these don't deal with taking/releasing locks. These will be used in following patches. Signed-off-by: Vivek Goyal --- fs/overlayfs/overlayfs.h | 2 ++ fs/overlayfs/util.c | 50 +++++++++++++++++++++++++++++------------------- 2 files changed, 32 insertions(+), 20 deletions(-) diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index aa5b0c121fc7..429713653b3b 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -273,7 +273,9 @@ void ovl_inuse_unlock(struct dentry *dentry); bool ovl_need_index(struct dentry *dentry); int ovl_nlink_prep(struct dentry *dentry); int ovl_nlink_start(struct dentry *dentry, bool *locked); +int ovl_nlink_start_locked(struct dentry *dentry); void ovl_nlink_end(struct dentry *dentry, bool locked); +void ovl_nlink_end_locked(struct dentry *dentry); int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); int ovl_check_metacopy_xattr(struct dentry *dentry); bool ovl_is_metacopy_dentry(struct dentry *dentry); diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index ed93e233894f..927960aa57ee 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -709,21 +709,13 @@ int ovl_nlink_prep(struct dentry *dentry) * Operations that change overlay inode and upper inode nlink need to be * synchronized with copy up for persistent nlink accounting. */ -int ovl_nlink_start(struct dentry *dentry, bool *locked) +int ovl_nlink_start_locked(struct dentry *dentry) { - struct ovl_inode *oi = OVL_I(d_inode(dentry)); const struct cred *old_cred; int err; - if (!d_inode(dentry)) - return 0; - - err = mutex_lock_interruptible(&oi->lock); - if (err) - return err; - if (d_is_dir(dentry) || !ovl_test_flag(OVL_INDEX, d_inode(dentry))) - goto out; + return 0; old_cred = ovl_override_creds(dentry->d_sb); /* @@ -734,8 +726,22 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked) */ err = ovl_set_nlink_upper(dentry); revert_creds(old_cred); + return err; +} -out: +int ovl_nlink_start(struct dentry *dentry, bool *locked) +{ + struct ovl_inode *oi = OVL_I(d_inode(dentry)); + int err; + + if (!d_inode(dentry)) + return 0; + + err = mutex_lock_interruptible(&oi->lock); + if (err) + return err; + + err = ovl_nlink_start_locked(dentry); if (err) mutex_unlock(&oi->lock); else @@ -744,18 +750,22 @@ int ovl_nlink_start(struct dentry *dentry, bool *locked) return err; } -void ovl_nlink_end(struct dentry *dentry, bool locked) +void ovl_nlink_end_locked(struct dentry *dentry) { - if (locked) { - if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) && - d_inode(dentry)->i_nlink == 0) { - const struct cred *old_cred; + if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) && + d_inode(dentry)->i_nlink == 0) { + const struct cred *old_cred; - old_cred = ovl_override_creds(dentry->d_sb); - ovl_cleanup_index(dentry); - revert_creds(old_cred); - } + old_cred = ovl_override_creds(dentry->d_sb); + ovl_cleanup_index(dentry); + revert_creds(old_cred); + } +} +void ovl_nlink_end(struct dentry *dentry, bool locked) +{ + if (locked) { + ovl_nlink_end_locked(dentry); mutex_unlock(&OVL_I(d_inode(dentry))->lock); } } -- 2.13.6