https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-4893 Lustre <p>It should be possible for a regular user to delete a file or directory if the remote MDT is available but the object does not exist using normal tools like rm and rmdir. </p> <p>Normally, "lfs rm_entry" is only allowed by the root user, and this will not delete remote entries even of they exist. </p> LU-4893

allow unlink for dangling entry

Improvement Major Closed Won't Fix WC Triage Richard Henwood dne dne2 Sat, 12 Apr 2014 16:05:08 +0000 Tue, 12 Dec 2017 19:17:11 +0000 Tue, 12 Dec 2017 19:17:11 +0000 Lustre 2.6.0 0 8 <p>This isn't really specific to DNE2 (striped directories), it also applies to DNE1 (remote directories).</p> <p>I recall the upstream kernel folks were unhappy with our ioctl (<tt>LL_IOC_REMOVE_ENTRY</tt>) to allow root to delete dangling entries like this. The problem with allowing non-root users to delete dangling entries is that it isn't possible to have proper permission checks for this, since the inode's UID/GID/ACL are on the remote (unavailable) MDT, and only the local permission of the directory can be used. For something like a striped /tmp directory with +S permissions this would allow any user to potentially disconnect a whole tree of files owned by another user.</p> <p>Oleg suggests to allow regular users to delete dangling subdirectories in directories that they own IFF the target MDT is online and available and reports that the directory is missing. </p> <p>In fact upstream hated it so much that LL_IOC_REMOVE_ENTRY has been deleted. Doesn't LFSCK replace this?</p> <p>This is needed in case some remote MDT is permanently removed, and the user/admin wants to delete the directory. While LFSCK could potentially fix this, that might take hours/days to scan and repair the whole filesystem depending on the size. Also, LFSCK will typically not repair components of the filesystem if some server is unavailable, on the assumption that the server will be restored. Otherwise, an ill-timed LFSCK run could clobber a large fraction of the filesystem if some OST or MDT is temporarily offline.</p> Development Rank 1|hzwjzb: Rank (Obsolete) 13529 Severity