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authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/fs/overlayfs/inode.c
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/fs/overlayfs/inode.c')
-rw-r--r--kernel/fs/overlayfs/inode.c97
1 files changed, 54 insertions, 43 deletions
diff --git a/kernel/fs/overlayfs/inode.c b/kernel/fs/overlayfs/inode.c
index 04f124884..05ac9a95e 100644
--- a/kernel/fs/overlayfs/inode.c
+++ b/kernel/fs/overlayfs/inode.c
@@ -12,8 +12,7 @@
#include <linux/xattr.h>
#include "overlayfs.h"
-static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr,
- bool no_data)
+static int ovl_copy_up_truncate(struct dentry *dentry)
{
int err;
struct dentry *parent;
@@ -30,10 +29,8 @@ static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr,
if (err)
goto out_dput_parent;
- if (no_data)
- stat.size = 0;
-
- err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat, attr);
+ stat.size = 0;
+ err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);
out_dput_parent:
dput(parent);
@@ -45,17 +42,32 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
int err;
struct dentry *upperdentry;
+ /*
+ * Check for permissions before trying to copy-up. This is redundant
+ * since it will be rechecked later by ->setattr() on upper dentry. But
+ * without this, copy-up can be triggered by just about anybody.
+ *
+ * We don't initialize inode->size, which just means that
+ * inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
+ * check for a swapfile (which this won't be anyway).
+ */
+ err = inode_change_ok(dentry->d_inode, attr);
+ if (err)
+ return err;
+
err = ovl_want_write(dentry);
if (err)
goto out;
- upperdentry = ovl_dentry_upper(dentry);
- if (upperdentry) {
+ err = ovl_copy_up(dentry);
+ if (!err) {
+ upperdentry = ovl_dentry_upper(dentry);
+
mutex_lock(&upperdentry->d_inode->i_mutex);
err = notify_change(upperdentry, attr, NULL);
+ if (!err)
+ ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
mutex_unlock(&upperdentry->d_inode->i_mutex);
- } else {
- err = ovl_copy_up_last(dentry, attr, false);
}
ovl_drop_write(dentry);
out:
@@ -140,11 +152,12 @@ struct ovl_link_data {
void *cookie;
};
-static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
{
- void *ret;
struct dentry *realdentry;
struct inode *realinode;
+ struct ovl_link_data *data = NULL;
+ const char *ret;
realdentry = ovl_dentry_real(dentry);
realinode = realdentry->d_inode;
@@ -152,28 +165,28 @@ static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
if (WARN_ON(!realinode->i_op->follow_link))
return ERR_PTR(-EPERM);
- ret = realinode->i_op->follow_link(realdentry, nd);
- if (IS_ERR(ret))
- return ret;
-
if (realinode->i_op->put_link) {
- struct ovl_link_data *data;
-
data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
- if (!data) {
- realinode->i_op->put_link(realdentry, nd, ret);
+ if (!data)
return ERR_PTR(-ENOMEM);
- }
data->realdentry = realdentry;
- data->cookie = ret;
+ }
- return data;
- } else {
- return NULL;
+ ret = realinode->i_op->follow_link(realdentry, cookie);
+ if (IS_ERR_OR_NULL(ret)) {
+ kfree(data);
+ return ret;
}
+
+ if (data)
+ data->cookie = *cookie;
+
+ *cookie = data;
+
+ return ret;
}
-static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
+static void ovl_put_link(struct inode *unused, void *c)
{
struct inode *realinode;
struct ovl_link_data *data = c;
@@ -182,7 +195,7 @@ static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
return;
realinode = data->realdentry->d_inode;
- realinode->i_op->put_link(data->realdentry, nd, data->cookie);
+ realinode->i_op->put_link(realinode, data->cookie);
kfree(data);
}
@@ -336,37 +349,36 @@ static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
return true;
}
-static int ovl_dentry_open(struct dentry *dentry, struct file *file,
- const struct cred *cred)
+struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
{
int err;
struct path realpath;
enum ovl_path_type type;
- bool want_write = false;
+
+ if (d_is_dir(dentry))
+ return d_backing_inode(dentry);
type = ovl_path_real(dentry, &realpath);
- if (ovl_open_need_copy_up(file->f_flags, type, realpath.dentry)) {
- want_write = true;
+ if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
err = ovl_want_write(dentry);
if (err)
- goto out;
+ return ERR_PTR(err);
- if (file->f_flags & O_TRUNC)
- err = ovl_copy_up_last(dentry, NULL, true);
+ if (file_flags & O_TRUNC)
+ err = ovl_copy_up_truncate(dentry);
else
err = ovl_copy_up(dentry);
+ ovl_drop_write(dentry);
if (err)
- goto out_drop_write;
+ return ERR_PTR(err);
ovl_path_upper(dentry, &realpath);
}
- err = vfs_open(&realpath, file, cred);
-out_drop_write:
- if (want_write)
- ovl_drop_write(dentry);
-out:
- return err;
+ if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE)
+ return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags);
+
+ return d_backing_inode(realpath.dentry);
}
static const struct inode_operations ovl_file_inode_operations = {
@@ -377,7 +389,6 @@ static const struct inode_operations ovl_file_inode_operations = {
.getxattr = ovl_getxattr,
.listxattr = ovl_listxattr,
.removexattr = ovl_removexattr,
- .dentry_open = ovl_dentry_open,
};
static const struct inode_operations ovl_symlink_inode_operations = {