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author | David Hildenbrand <david@redhat.com> | 2021-04-23 09:45:45 +0200 |
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committer | David Hildenbrand <david@redhat.com> | 2021-09-03 18:42:02 +0200 |
commit | 592ca09be8333bd226f50100328a905bfc377133 (patch) | |
tree | 8a570be052c4eac24b614f38448f6b83d7a04e6e /include/linux/fs.h | |
parent | 6128b3af2a5e42386aa7faf37609b57f39fb7d00 (diff) | |
download | linux-stable-592ca09be8333bd226f50100328a905bfc377133.tar.gz linux-stable-592ca09be8333bd226f50100328a905bfc377133.tar.bz2 linux-stable-592ca09be8333bd226f50100328a905bfc377133.zip |
fs: update documentation of get_write_access() and friends
As VM_DENYWRITE does no longer exists, let's spring-clean the
documentation of get_write_access() and friends.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Diffstat (limited to 'include/linux/fs.h')
-rw-r--r-- | include/linux/fs.h | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 640574294216..e0dc3e96ed72 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3055,15 +3055,20 @@ static inline void file_end_write(struct file *file) } /* + * This is used for regular files where some users -- especially the + * currently executed binary in a process, previously handled via + * VM_DENYWRITE -- cannot handle concurrent write (and maybe mmap + * read-write shared) accesses. + * * get_write_access() gets write permission for a file. * put_write_access() releases this write permission. - * This is used for regular files. - * We cannot support write (and maybe mmap read-write shared) accesses and - * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode - * can have the following values: - * 0: no writers, no VM_DENYWRITE mappings - * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist - * > 0: (i_writecount) users are writing to the file. + * deny_write_access() denies write access to a file. + * allow_write_access() re-enables write access to a file. + * + * The i_writecount field of an inode can have the following values: + * 0: no write access, no denied write access + * < 0: (-i_writecount) users that denied write access to the file. + * > 0: (i_writecount) users that have write access to the file. * * Normally we operate on that counter with atomic_{inc,dec} and it's safe * except for the cases where we don't hold i_writecount yet. Then we need to |