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Style cleanup for O_DIRECT sysctl comment introduced in nfs_vnops.c:1.242.

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This commit is contained in:
Robert Watson 2005-01-29 23:19:08 +00:00
parent 03edfff39a
commit 38aa565976
1 changed files with 9 additions and 8 deletions
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17
sys/nfsclient/nfs_vnops.c
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@ -216,14 +216,15 @@ SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_directio_enable, CTLFLAG_RW,
&nfs_directio_enable, 0, "Enable NFS directio");
/*
* This sysctl allows other processes to mmap a file that has been opened O_DIRECT
* by a process. In general, having processes mmap the file while Direct IO is in
* progress can lead to Data Inconsistencies. But, we allow this by default to
* prevent DoS attacks - to prevent a malicious user from opening up files O_DIRECT
* preventing other users from mmap'ing these files. "Protected" environments where
* stricter consistency guarantees are required can disable this knob.
* The process that opened the file O_DIRECT cannot mmap() the file, because
* mmap'ed IO on an O_DIRECT open() is not meaningful.
* This sysctl allows other processes to mmap a file that has been opened
* O_DIRECT by a process. In general, having processes mmap the file while
* Direct IO is in progress can lead to Data Inconsistencies. But, we allow
* this by default to prevent DoS attacks - to prevent a malicious user from
* opening up files O_DIRECT preventing other users from mmap'ing these
* files. "Protected" environments where stricter consistency guarantees are
* required can disable this knob. The process that opened the file O_DIRECT
* cannot mmap() the file, because mmap'ed IO on an O_DIRECT open() is not
* meaningful.
*/
int nfs_directio_allow_mmap = 1;
SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_directio_allow_mmap, CTLFLAG_RW,