On Mon, Jul 23, 2018 at 05:26:24PM +0200, David Sterba wrote: > On Wed, Jul 18, 2018 at 12:08:59AM +0200, Adam Borowski wrote: (Combined with as-folded)
| | btrfs: allow defrag on a file opened read-only that has rw permissions | | > > Requiring a rw descriptor conflicts both ways with exec, returning ETXTBSY > > whenever you try to defrag a program that's currently being run, or > > causing intermittent exec failures on a live system being defragged. > > > > As defrag doesn't change the file's contents in any way, there's no reason > > to consider it a rw operation. Thus, let's check only whether the file > > could have been opened rw. Such access control is still needed as > > currently defrag can use extra disk space, and might trigger bugs. <----- | | We give EINVAL when the request is invalid; here it's ok but merely the | | user has insufficient privileges. Thus, this return value reflects the | | error better -- as discussed in the identical case for dedupe. | | | | According to codesearch.debian.net, no userspace program distinguishes | | these values beyond strerror(). | | | | Signed-off-by: Adam Borowski <kilob...@angband.pl> | | Reviewed-by: David Sterba <dste...@suse.com> | | [ fold the EPERM patch from Adam ] | | Signed-off-by: David Sterba <dste...@suse.com> [...] > So, I'll add the patch to 4.19 queue. It's small and isolated change so > a revert would be easy in case we find something bad. The 2nd patch > should be IMHO part of this change as it's logical to return the error > code in the patch that modifies the user visible behaviour. A nitpick: the new commit message has a dangling pointer "this" to the title of the commit that was squashed. It was: | btrfs: defrag: return EPERM not EINVAL when only permissions fail It'd be nice if it could be inserted in some form in the place I marked with an arrow. But then, commit messages are not vital. The actual functionality patch has been applied correctly. And thanks for adding the comment. Meow! -- // If you believe in so-called "intellectual property", please immediately // cease using counterfeit alphabets. Instead, contact the nearest temple // of Amon, whose priests will provide you with scribal services for all // your writing needs, for Reasonable And Non-Discriminatory prices. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
