| Message ID | 158520021604.5325.4342529050022426912.stgit@mickey.themaw.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] autofs: dont call do_expire_wait() in autofs_d_manage() | expand |
One nit, below. Vince On Thu, Mar 26, 2020 at 01:23:36PM +0800, Ian Kent wrote: >The function autofs_mountpoint_changed() is unusual, add a comment >about two cases for which it is used. > >Signed-off-by: Ian Kent <raven@themaw.net> >--- > fs/autofs/root.c | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > >diff --git a/fs/autofs/root.c b/fs/autofs/root.c >index 308cc49aca1d..a972bbaecb46 100644 >--- a/fs/autofs/root.c >+++ b/fs/autofs/root.c >@@ -280,9 +280,24 @@ static struct dentry *autofs_mountpoint_changed(struct path *path) > struct dentry *dentry = path->dentry; > struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); > >- /* >- * If this is an indirect mount the dentry could have gone away >- * as a result of an expire and a new one created. >+ /* If this is an indirect mount the dentry could have gone away >+ * and a new one created. >+ * >+ * This is unusual and I can't remember the case for which it >+ * was originally added now. But a example of how this can 'an' example >+ * happen is an autofs indirect mount that has the "browse" >+ * option set and also has the "symlink" option in the autofs >+ * map entry. In this case the daemon will remove the browse >+ * directory and create a symlink as the mount (pointing to a >+ * local path) leaving the struct path stale. >+ * >+ * Another not so obvious case is when a mount in an autofs >+ * indirect mount that uses the "nobrowse" option is being >+ * expired and the mount has been umounted but the mount point >+ * directory remains when a stat family system call is made. >+ * In this case the mount point is removed (by the daemon) and >+ * a new mount triggered leading to a stale dentry in the struct >+ * path of the waiting process. > */ > if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { > struct dentry *parent = dentry->d_parent; > --
On Fri, 2020-03-27 at 05:19 +0000, McIntyre, Vincent (CASS, Marsfield) wrote: > One nit, below. Yeah, thanks for that, you effort looking at the patches is appreciated, I'll fix it. > Vince > > On Thu, Mar 26, 2020 at 01:23:36PM +0800, Ian Kent wrote: > > The function autofs_mountpoint_changed() is unusual, add a comment > > about two cases for which it is used. > > > > Signed-off-by: Ian Kent <raven@themaw.net> > > --- > > fs/autofs/root.c | 21 ++++++++++++++++++--- > > 1 file changed, 18 insertions(+), 3 deletions(-) > > > > diff --git a/fs/autofs/root.c b/fs/autofs/root.c > > index 308cc49aca1d..a972bbaecb46 100644 > > --- a/fs/autofs/root.c > > +++ b/fs/autofs/root.c > > @@ -280,9 +280,24 @@ static struct dentry > > *autofs_mountpoint_changed(struct path *path) > > struct dentry *dentry = path->dentry; > > struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); > > > > - /* > > - * If this is an indirect mount the dentry could have gone away > > - * as a result of an expire and a new one created. > > + /* If this is an indirect mount the dentry could have gone away > > + * and a new one created. > > + * > > + * This is unusual and I can't remember the case for which it > > + * was originally added now. But a example of how this can > > 'an' example > > > + * happen is an autofs indirect mount that has the "browse" > > + * option set and also has the "symlink" option in the autofs > > + * map entry. In this case the daemon will remove the browse > > + * directory and create a symlink as the mount (pointing to a > > + * local path) leaving the struct path stale. > > + * > > + * Another not so obvious case is when a mount in an autofs > > + * indirect mount that uses the "nobrowse" option is being > > + * expired and the mount has been umounted but the mount point > > + * directory remains when a stat family system call is made. > > + * In this case the mount point is removed (by the daemon) and > > + * a new mount triggered leading to a stale dentry in the > > struct > > + * path of the waiting process. > > */ > > if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { > > struct dentry *parent = dentry->d_parent; > > > > --
diff --git a/fs/autofs/root.c b/fs/autofs/root.c index 308cc49aca1d..a972bbaecb46 100644 --- a/fs/autofs/root.c +++ b/fs/autofs/root.c @@ -280,9 +280,24 @@ static struct dentry *autofs_mountpoint_changed(struct path *path) struct dentry *dentry = path->dentry; struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); - /* - * If this is an indirect mount the dentry could have gone away - * as a result of an expire and a new one created. + /* If this is an indirect mount the dentry could have gone away + * and a new one created. + * + * This is unusual and I can't remember the case for which it + * was originally added now. But a example of how this can + * happen is an autofs indirect mount that has the "browse" + * option set and also has the "symlink" option in the autofs + * map entry. In this case the daemon will remove the browse + * directory and create a symlink as the mount (pointing to a + * local path) leaving the struct path stale. + * + * Another not so obvious case is when a mount in an autofs + * indirect mount that uses the "nobrowse" option is being + * expired and the mount has been umounted but the mount point + * directory remains when a stat family system call is made. + * In this case the mount point is removed (by the daemon) and + * a new mount triggered leading to a stale dentry in the struct + * path of the waiting process. */ if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { struct dentry *parent = dentry->d_parent;
The function autofs_mountpoint_changed() is unusual, add a comment about two cases for which it is used. Signed-off-by: Ian Kent <raven@themaw.net> --- fs/autofs/root.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)