xfs: allow sysadmins to specify a maximum atomic write limit at mount time
Introduce a mount option to allow sysadmins to specify the maximum size
of an atomic write. If the filesystem can work with the supplied value,
that becomes the new guaranteed maximum.
The value mustn't be too big for the existing filesystem geometry (max
write size, max AG/rtgroup size). We dynamically recompute the
tr_atomic_write transaction reservation based on the given block size,
check that the current log size isn't less than the new minimum log size
constraints, and set a new maximum.
The actual software atomic write max is still computed based off of
tr_atomic_ioend the same way it has for the past few commits.
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
7 files changed
