diff options
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 5c7cc953ac81..95d71eda8142 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -26,7 +26,7 @@ #include <linux/export.h> #include <linux/mount.h> #include <linux/file.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #include <linux/security.h> #include <linux/seqlock.h> #include <linux/swap.h> @@ -1273,38 +1273,44 @@ rename_retry: goto again; } -/* - * Search for at least 1 mount point in the dentry's subdirs. - * We descend to the next level whenever the d_subdirs - * list is non-empty and continue searching. - */ +struct check_mount { + struct vfsmount *mnt; + unsigned int mounted; +}; -static enum d_walk_ret check_mount(void *data, struct dentry *dentry) +static enum d_walk_ret path_check_mount(void *data, struct dentry *dentry) { - int *ret = data; - if (d_mountpoint(dentry)) { - *ret = 1; + struct check_mount *info = data; + struct path path = { .mnt = info->mnt, .dentry = dentry }; + + if (likely(!d_mountpoint(dentry))) + return D_WALK_CONTINUE; + if (__path_is_mountpoint(&path)) { + info->mounted = 1; return D_WALK_QUIT; } return D_WALK_CONTINUE; } /** - * have_submounts - check for mounts over a dentry - * @parent: dentry to check. + * path_has_submounts - check for mounts over a dentry in the + * current namespace. + * @parent: path to check. * * Return true if the parent or its subdirectories contain - * a mount point + * a mount point in the current namespace. */ -int have_submounts(struct dentry *parent) +int path_has_submounts(const struct path *parent) { - int ret = 0; + struct check_mount data = { .mnt = parent->mnt, .mounted = 0 }; - d_walk(parent, &ret, check_mount, NULL); + read_seqlock_excl(&mount_lock); + d_walk(parent->dentry, &data, path_check_mount, NULL); + read_sequnlock_excl(&mount_lock); - return ret; + return data.mounted; } -EXPORT_SYMBOL(have_submounts); +EXPORT_SYMBOL(path_has_submounts); /* * Called by mount code to set a mountpoint and check if the mountpoint is @@ -1330,8 +1336,11 @@ int d_set_mounted(struct dentry *dentry) } spin_lock(&dentry->d_lock); if (!d_unlinked(dentry)) { - dentry->d_flags |= DCACHE_MOUNTED; - ret = 0; + ret = -EBUSY; + if (!d_mountpoint(dentry)) { + dentry->d_flags |= DCACHE_MOUNTED; + ret = 0; + } } spin_unlock(&dentry->d_lock); out: |