cifs: have ->mkdir() handle race with another client sanely

if we have mkdir request reported successful *and* simulating lookup
gets us a non-directory (which is possible if another client has
managed to get rmdir and create in between), the sane action is not
to mangle ->i_mode of non-directory inode to S_IFDIR | mode, it's
"report success and return with dentry negative unhashed" - that
way the next lookup will do the right thing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2021-02-10 22:13:03 -05:00
parent 4ab5260dab
commit 3bcb39b086

View File

@ -1739,6 +1739,16 @@ cifs_mkdir_qinfo(struct inode *parent, struct dentry *dentry, umode_t mode,
if (rc)
return rc;
if (!S_ISDIR(inode->i_mode)) {
/*
* mkdir succeeded, but another client has managed to remove the
* sucker and replace it with non-directory. Return success,
* but don't leave the child in dcache.
*/
iput(inode);
d_drop(dentry);
return 0;
}
/*
* setting nlink not necessary except in cases where we failed to get it
* from the server or was set bogus. Also, since this is a brand new
@ -1790,7 +1800,7 @@ cifs_mkdir_qinfo(struct inode *parent, struct dentry *dentry, umode_t mode,
}
}
d_instantiate(dentry, inode);
return rc;
return 0;
}
static int