[PATCH 1/3] fs: Introduce new flag FALLOC_FL_COLLAPSE_RANGE

[Theodore Ts'o]

Have you considered what happens if you have a 10 megabyte file, of
which the first 5 megs are mmap'ed into a userspace process.

Now suppose you call COLLAPASE_RANGE on a one megabyte range starting
at offset 1024k from the beginning of the file.

Does the right thing happen to the mmap'ed region in memory?

Cheers,

					- Ted