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ovl: store ovl_entry in inode->i_private for all inodes

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Previously this was only done for directory inodes.  Doing so for all
inodes makes for a nice cleanup in ovl_permission at zero cost.

Inodes are not shared for hard links on the overlay, so this works fine.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Andreas Gruenbacher 2016-05-26 02:01:47 +02:00 committed by Miklos Szeredi
parent eead4f2dc4
commit 58ed4e70f2
1 changed files with 11 additions and 37 deletions
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48
fs/overlayfs/inode.c
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@ -109,31 +109,12 @@ static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry,
int ovl_permission(struct inode *inode, int mask)
{
struct ovl_entry *oe;
struct dentry *alias = NULL;
struct inode *realinode;
struct dentry *realdentry;
struct ovl_entry *oe = inode->i_private;
bool is_upper;
struct dentry *realdentry = ovl_entry_real(oe, &is_upper);
struct inode *realinode;
int err;
if (S_ISDIR(inode->i_mode)) {
oe = inode->i_private;
} else if (mask & MAY_NOT_BLOCK) {
return -ECHILD;
} else {
/*
* For non-directories find an alias and get the info
* from there.
*/
alias = d_find_any_alias(inode);
if (WARN_ON(!alias))
return -ENOENT;
oe = alias->d_fsdata;
}
realdentry = ovl_entry_real(oe, &is_upper);
if (ovl_is_default_permissions(inode)) {
struct kstat stat;
struct path realpath = { .dentry = realdentry };
@ -145,26 +126,23 @@ int ovl_permission(struct inode *inode, int mask)
err = vfs_getattr(&realpath, &stat);
if (err)
goto out_dput;
return err;
err = -ESTALE;
if ((stat.mode ^ inode->i_mode) & S_IFMT)
goto out_dput;
return -ESTALE;
inode->i_mode = stat.mode;
inode->i_uid = stat.uid;
inode->i_gid = stat.gid;
err = generic_permission(inode, mask);
goto out_dput;
return generic_permission(inode, mask);
}
/* Careful in RCU walk mode */
realinode = ACCESS_ONCE(realdentry->d_inode);
realinode = d_inode_rcu(realdentry);
if (!realinode) {
WARN_ON(!(mask & MAY_NOT_BLOCK));
err = -ENOENT;
goto out_dput;
return -ENOENT;
}
if (mask & MAY_WRITE) {
@ -183,16 +161,12 @@ int ovl_permission(struct inode *inode, int mask)
* constructed return EROFS to prevent modification of
* upper layer.
*/
err = -EROFS;
if (is_upper && !IS_RDONLY(inode) && IS_RDONLY(realinode) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
goto out_dput;
return -EROFS;
}
err = __inode_permission(realinode, mask);
out_dput:
dput(alias);
return err;
return __inode_permission(realinode, mask);
}
static const char *ovl_get_link(struct dentry *dentry,
@ -405,11 +379,11 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_flags |= S_NOATIME | S_NOCMTIME;
inode->i_private = oe;
mode &= S_IFMT;
switch (mode) {
case S_IFDIR:
inode->i_private = oe;
inode->i_op = &ovl_dir_inode_operations;
inode->i_fop = &ovl_dir_operations;
break;