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In >> f2fs, this is done in the following path: >> >> - write_begin >> - f2fs_write_begin >> - __filemap_get_folio >> As I understand it, if we don't set the FGP_DONTCACHE flag here, this >> issue shouldn't occur. > It won't cause an issue, but it also won't work in the sense that the > intent is that if the file system doesn't support DONTCACHE, it would > get errored at submission time. Your approach would just ignore the flag > for writes, rather than return -EOPNOTSUPP as would be expected. > > You could potentially make it work just on the read side by having the > f2fs write submit side check DONTCACHE on the write side and error them > out. Hi Jens, Thank you for your suggestions. I am currently working on modifying F2FS to handle the dontcache unmap operation in a workqueue. I expect to submit the patch soon, after which F2FS should also support uncached buffer I/O writes. Thanks, >