Messages in this thread | | | From | David Laight <> | Subject | RE: [RFC PATCH V2 09/12] fs: Prevent mode change if file is mmap'ed | Date | Wed, 15 Jan 2020 10:21:45 +0000 |
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From ira.weiny@intel.com > Sent: 10 January 2020 19:30 > > Page faults need to ensure the inode mode is correct and consistent with > the vmf information at the time of the fault. There is no easy way to > ensure the vmf information is correct if a mode change is in progress. > Furthermore, there is no good use case to require a mode change while > the file is mmap'ed. > > Track mmap's of the file and fail the mode change if the file is > mmap'ed.
This seems wrong to me. I presume the 'mode changes' are from things like 'chmod -w ...'. mmap() should be no different to open(). Only the permissions set when the file is opened count.
Next you'll be stopping unlink() when a file is open :-)
David
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