diff options
| author |   Abhi Das <adas@redhat.com> | 2023-11-10 13:10:08 +0100 |
|---|---|---|
| committer |   Andreas Gruenbacher <agruenba@redhat.com> | 2023-12-18 14:24:33 +0100 |
| commit | dd00aaeb343255a8a30de671bd27bde79a47c8e5 (patch) | |
| tree | 521dfaa2891b730c7d8260905c2bde3579102fd5 | |
| parent | gfs2: Add GL_NOBLOCK flag (diff) | |
| download | wireguard-linux-dd00aaeb343255a8a30de671bd27bde79a47c8e5.tar.xz wireguard-linux-dd00aaeb343255a8a30de671bd27bde79a47c8e5.zip | |
gfs2: Use GL_NOBLOCK flag for non-blocking lookups
Add the GL_NOBLOCK flag to the locking requests in gfs2_permission() and
gfs2_drevalidate() when called with the MAY_NOT_BLOCK flag and
LOOKUP_RCU flag, respectively. This will cause the locking requests to
be handled without sleeping if possible. We bail out with -ECHILD if we
can't grant the glock immediately.
Make sure not to dget() + dput() the parent dentry in gfs2_drevalidate()
in LOOKUP_RCU mode; dput() is a sleeping operation.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
| -rw-r--r-- | fs/gfs2/dentry.c | 23 | ||||
| -rw-r--r-- | fs/gfs2/inode.c | 8 |
2 files changed, 18 insertions, 13 deletions
diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c index 2e215e8c3c88..177f1f41f225 100644 --- a/fs/gfs2/dentry.c +++ b/fs/gfs2/dentry.c @@ -32,21 +32,25 @@ static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags) { - struct dentry *parent; + struct dentry *parent = NULL; struct gfs2_sbd *sdp; struct gfs2_inode *dip; - struct inode *inode; + struct inode *dinode, *inode; struct gfs2_holder d_gh; struct gfs2_inode *ip = NULL; int error, valid = 0; int had_lock = 0; - if (flags & LOOKUP_RCU) - return -ECHILD; - - parent = dget_parent(dentry); - sdp = GFS2_SB(d_inode(parent)); - dip = GFS2_I(d_inode(parent)); + if (flags & LOOKUP_RCU) { + dinode = d_inode_rcu(READ_ONCE(dentry->d_parent)); + if (!dinode) + return -ECHILD; + } else { + parent = dget_parent(dentry); + dinode = d_inode(parent); + } + sdp = GFS2_SB(dinode); + dip = GFS2_I(dinode); inode = d_inode(dentry); if (inode) { @@ -62,7 +66,8 @@ static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags) had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL); if (!had_lock) { - error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, + flags & LOOKUP_RCU ? GL_NOBLOCK : 0, &d_gh); if (error) goto out; } diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 1b95db2c3aac..6bfc9383b7b8 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -1882,10 +1882,10 @@ int gfs2_permission(struct mnt_idmap *idmap, struct inode *inode, WARN_ON_ONCE(!may_not_block); return -ECHILD; } - if (gfs2_glock_is_locked_by_me(gl) == NULL) { - if (may_not_block) - return -ECHILD; - error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); + if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) { + int noblock = may_not_block ? GL_NOBLOCK : 0; + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, + LM_FLAG_ANY | noblock, &i_gh); if (error) return error; } |