Hello, this is a patch series that addresses a possible race between readahead and hole punching Amir has discovered [1]. The first patch makes madvise(2) to handle readahead requests through fadvise infrastructure, the third patch then adds necessary locking to XFS to protect against the race. Note that other filesystems need similar protections but e.g. in case of ext4 it isn't so simple without seriously regressing mixed rw workload performance so I'm pushing just xfs fix at this moment which is simple. Changes since v1 (posted at [2]): * Added reviewed-by tags * Fixed indentation in xfs_file_fadvise() * Improved comment and readibility of xfs_file_fadvise() Honza [1] https://lore.kernel.org/linux-fsdevel/CAOQ4uxjQNmxqmtA_VbYW0Su9rKRk2zobJmahcyeaEVOFKVQ5dw@xxxxxxxxxxxxxx/ [2] https://lore.kernel.org/linux-fsdevel/20190711140012.1671-1-jack@xxxxxxx/
