Commit e8e96157 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds

fuse: clean up execute permission checking

Define a new function fuse_refresh_attributes() that conditionally refreshes
the attributes based on the validity timeout.

In fuse_permission() only refresh the attributes for checking the execute bits
if necessary.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c9c9d7df
......@@ -694,6 +694,20 @@ static int fuse_do_getattr(struct inode *inode)
return err;
}
/*
* Check if attributes are still valid, and if not send a GETATTR
* request to refresh them.
*/
static int fuse_refresh_attributes(struct inode *inode)
{
struct fuse_inode *fi = get_fuse_inode(inode);
if (fi->i_time < get_jiffies_64())
return fuse_do_getattr(inode);
else
return 0;
}
/*
* Calling into a user-controlled filesystem gives the filesystem
* daemon ptrace-like capabilities over the requester process. This
......@@ -770,7 +784,6 @@ static int fuse_access(struct inode *inode, int mask)
static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
bool refreshed = false;
int err = 0;
......@@ -778,12 +791,11 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
return -EACCES;
/*
* If attributes are needed, but are stale, refresh them
* before proceeding
* If attributes are needed, refresh them before proceeding
*/
if (((fc->flags & FUSE_DEFAULT_PERMISSIONS) || (mask & MAY_EXEC)) &&
fi->i_time < get_jiffies_64()) {
err = fuse_do_getattr(inode);
if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
err = fuse_refresh_attributes(inode);
if (err)
return err;
......@@ -806,14 +818,17 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
exist. So if permissions are revoked this won't be
noticed immediately, only after the attribute
timeout has expired */
} else {
int mode = inode->i_mode;
if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
} else if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR))) {
err = fuse_access(inode, mask);
} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
if (!(inode->i_mode & S_IXUGO)) {
if (refreshed)
return -EACCES;
if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR)))
return fuse_access(inode, mask);
err = fuse_do_getattr(inode);
if (!err && !(inode->i_mode & S_IXUGO))
return -EACCES;
}
}
return err;
}
......@@ -1046,14 +1061,12 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
struct inode *inode = entry->d_inode;
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
int err = 0;
int err;
if (!fuse_allow_task(fc, current))
return -EACCES;
if (fi->i_time < get_jiffies_64())
err = fuse_do_getattr(inode);
err = fuse_refresh_attributes(inode);
if (!err) {
generic_fillattr(inode, stat);
stat->mode = fi->orig_i_mode;
......
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