linux - Does O_DIRECT bypass filesystem journaling? -

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the man page open(2) suggests o_direct bypasses page cache, many descriptions around net describe causing user buffer dma'd straight drive. if case imagine bypass journaling done filesystem (e.g. xfs, ext4, etc.). case?

i can't find claiming 1 way or other. seems me consistent o_direct being used databases -- common example use o_direct when application database doing own caching in userspace, , can imagine databases doing own transaction logs.


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