[PATCH v1 7/7] fs: update documentation of get_write_access() and friends
From: David Hildenbrand <hidden>
Date: 2021-08-12 08:46:39
Also in:
linux-api, linux-fsdevel, linux-unionfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
As VM_DENYWRITE does no longer exists, let's spring-clean the documentation of get_write_access() and friends. Signed-off-by: David Hildenbrand <redacted> --- include/linux/fs.h | 19 ++++++++++++------- 1 file 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
--
2.31.1