linux.git/fs/open.c, branch v3.6

vfs: canonicalize create mode in build_open_flags()

2012-08-15T11:01:24+00:00

Userspace can pass weird create mode in open(2) that we canonicalize to 
"(mode & S_IALLUGO) | S_IFREG" in vfs_create().

The problem is that we use the uncanonicalized mode before calling vfs_create()
with unforseen consequences.

So do the canonicalization early in build_open_flags().

Signed-off-by: Miklos Szeredi 
Tested-by: Richard W.M. Jones 
CC: stable@vger.kernel.org

missed mnt_drop_write() in do_dentry_open()

2012-08-04T08:15:41+00:00

This one ought to be __mnt_drop_write(), to match __mnt_want_write()
in the beginning...

Signed-off-by: Al Viro

fs: Protect write paths by sb_start_write - sb_end_write

2012-07-31T05:45:47+00:00

There are several entry points which dirty pages in a filesystem.  mmap
(handled by block_page_mkwrite()), buffered write (handled by
__generic_file_aio_write()), splice write (generic_file_splice_write),
truncate, and fallocate (these can dirty last partial page - handled inside
each filesystem separately). Protect these places with sb_start_write() and
sb_end_write().

->page_mkwrite() calls are particularly complex since they are called with
mmap_sem held and thus we cannot use standard sb_start_write() due to lock
ordering constraints. We solve the problem by using a special freeze protection
sb_start_pagefault() which ranks below mmap_sem.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa 
Tested-by: Peter M. Petrakis 
Tested-by: Dann Frazier 
Tested-by: Massimo Morana 
Signed-off-by: Jan Kara 
Signed-off-by: Al Viro

fs: Add freezing handling to mnt_want_write() / mnt_drop_write()

2012-07-31T05:40:38+00:00

Most of places where we want freeze protection coincides with the places where
we also have remount-ro protection. So make mnt_want_write() and
mnt_drop_write() (and their _file alternative) prevent freezing as well.
For the few cases that are really interested only in remount-ro protection
provide new function variants.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa 
Tested-by: Peter M. Petrakis 
Tested-by: Dann Frazier 
Tested-by: Massimo Morana 
Signed-off-by: Jan Kara 
Signed-off-by: Al Viro

take grabbing f->f_path to do_dentry_open()

2012-07-29T17:24:18+00:00

Signed-off-by: Al Viro

switch dentry_open() to struct path, make it grab references itself

2012-07-22T20:01:29+00:00

Signed-off-by: Al Viro

VFS: Make chown() and lchown() call fchownat()

2012-07-14T12:35:54+00:00

Make the chown() and lchown() syscalls jump to the fchownat() syscall with the
appropriate extra arguments.

Signed-off-by: David Howells 
Signed-off-by: Al Viro

do_dentry_open(): close the race with mark_files_ro() in failure exit

2012-07-14T12:35:50+00:00

we want to take it out of mark_files_ro() reach *before* we start
checking if we ought to drop write access.

Signed-off-by: Al Viro

do_dentry_open(): take initialization of file->f_path to caller

2012-07-14T12:33:54+00:00

... and get rid of a couple of arguments and a pointless reassignment
in finish_open() case.

Signed-off-by: Al Viro

fold __dentry_open() into its sole caller

2012-07-14T12:33:52+00:00

Signed-off-by: Al Viro