On Mon, Sep 07, 2015 at 05:10:11PM -0400, Mike Marshall wrote: > I have failed so far today to figure out what you mean by GrepTFS or GTFS... grep the fucking source, of course... > and https://lwn.net/lwn/kernel/LDD2/ch07.html... I don't yet see where we're > doing GFP_KERNEL allocations within held locks... could you describe in more > detail one of the ones you saw? You don't want e.g. to have allocation request triggering an attempt to write a dirty page on a shared mapping of a file from your fs while you are holding a mutex that would block that attempt *and* waiting for a allocation to succeed. Same story as when a block driver needs to allocate something to process a write request - we do _not_ want that to trigger writes. That's what GFP_NOFS and GFP_NOIO are about; LDD2 is old and the analogue back then used to be called GFP_BUFFER. Which (if any) is needed depends on the locks you are holding; something like ->i_mutex on a directory is not a problem, but things like your request mutex almost certainly *are*. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
