diff options
author | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-11 10:41:07 +0300 |
---|---|---|
committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-13 08:17:18 +0300 |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/fs/overlayfs/inode.c | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (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.c | 97 |
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 = { |