linux-stable.git/fs/inode.c, branch v4.4.239

futex: Fix inode life-time issue

2020-04-02T17:02:31+00:00

commit 8019ad13ef7f64be44d4f892af9c840179009254 upstream.

As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.

This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.

Reported-by: Jann Horn 
Suggested-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Greg Kroah-Hartman

Abort file_remove_privs() for non-reg. files

2019-06-22T06:18:27+00:00

commit f69e749a49353d96af1a293f56b5b56de59c668a upstream.

file_remove_privs() might be called for non-regular files, e.g.
blkdev inode. There is no reason to do its job on things
like blkdev inodes, pipes, or cdevs. Hence, abort if
file does not refer to a regular inode.

AV: more to the point, for devices there might be any number of
inodes refering to given device.  Which one to strip the permissions
from, even if that made any sense in the first place?  All of them
will be observed with contents modified, after all.

Found by LockDoc (Alexander Lochmann, Horst Schirmeier and Olaf
Spinczyk)

Reviewed-by: Jan Kara 
Signed-off-by: Alexander Lochmann 
Signed-off-by: Horst Schirmeier 
Signed-off-by: Al Viro 
Cc: Zubin Mithra 
Signed-off-by: Greg Kroah-Hartman

writeback: initialize inode members that track writeback history

2019-04-03T04:23:21+00:00

[ Upstream commit 3d65ae4634ed8350aee98a4e6f4e41fe40c7d282 ]

inode struct members that track cgroup writeback information
should be reinitialized when inode gets allocated from
kmem_cache. Otherwise, their values remain and get used by the
new inode.

Signed-off-by: Tahsin Erdogan 
Acked-by: Tejun Heo 
Fixes: d10c80955265 ("writeback: implement foreign cgroup inode bdi_writeback switching")
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

Fix up non-directory creation in SGID directories

2018-07-17T09:31:43+00:00

commit 0fa3ecd87848c9c93c2c828ef4c3a8ca36ce46c7 upstream.

sgid directories have special semantics, making newly created files in
the directory belong to the group of the directory, and newly created
subdirectories will also become sgid.  This is historically used for
group-shared directories.

But group directories writable by non-group members should not imply
that such non-group members can magically join the group, so make sure
to clear the sgid bit on non-directories for non-members (but remember
that sgid without group execute means "mandatory locking", just to
confuse things even more).

Reported-by: Jann Horn 
Cc: Andy Lutomirski 
Cc: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

don't put symlink bodies in pagecache into highmem

2018-02-16T19:09:38+00:00

commit 21fc61c73c3903c4c312d0802da01ec2b323d174 upstream.

kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.

new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases.  page_follow_link_light()
instrumented to yell about anything missed.

Signed-off-by: Al Viro 
Signed-off-by: Jin Qian 
Signed-off-by: Jin Qian 
Signed-off-by: Greg Kroah-Hartman

vfs: fix deadlock in file_remove_privs() on overlayfs

2016-08-10T09:49:30+00:00

commit c1892c37769cf89c7e7ba57528ae2ccb5d153c9b upstream.

file_remove_privs() is called with inode lock on file_inode(), which
proceeds to calling notify_change() on file->f_path.dentry.  Which triggers
the WARN_ON_ONCE(!inode_is_locked(inode)) in addition to deadlocking later
when ovl_setattr tries to lock the underlying inode again.

Fix this mess by not mixing the layers, but doing everything on underlying
dentry/inode.

Signed-off-by: Miklos Szeredi 
Fixes: 07a2daab49c5 ("ovl: Copy up underlying inode's ->i_mode to overlay inode")
Signed-off-by: Greg Kroah-Hartman

fs/inode.c: fix kernel-doc warning

2015-11-09T23:11:24+00:00

Fix kernel-doc warning in fs/inode.c:

  ../fs/inode.c:1606: warning: No description found for parameter 'inode'

Signed-off-by: Randy Dunlap 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

inode: don't softlockup when evicting inodes

2015-08-18T17:20:09+00:00

On a box with a lot of ram (148gb) I can make the box softlockup after running
an fs_mark job that creates hundreds of millions of empty files.  This is
because we never generate enough memory pressure to keep the number of inodes on
our unused list low, so when we go to unmount we have to evict ~100 million
inodes.  This makes one processor a very unhappy person, so add a cond_resched()
in dispose_list() and if we need a resched when processing the s_inodes list do
that and run dispose_list() on what we've currently culled.  Thanks,

Signed-off-by: Josef Bacik 
Reviewed-by: Jan Kara

inode: rename i_wb_list to i_io_list

2015-08-18T03:38:10+00:00

There's a small consistency problem between the inode and writeback
naming. Writeback calls the "for IO" inode queues b_io and
b_more_io, but the inode calls these the "writeback list" or
i_wb_list. This makes it hard to an new "under writeback" list to
the inode, or call it an "under IO" list on the bdi because either
way we'll have writeback on IO and IO on writeback and it'll just be
confusing. I'm getting confused just writing this!

So, rename the inode "for IO" list variable to i_io_list so we can
add a new "writeback list" in a subsequent patch.

Signed-off-by: Dave Chinner 
Signed-off-by: Josef Bacik 
Reviewed-by: Jan Kara 
Reviewed-by: Christoph Hellwig 
Tested-by: Dave Chinner

inode: convert inode_sb_list_lock to per-sb

2015-08-17T22:39:46+00:00

The process of reducing contention on per-superblock inode lists
starts with moving the locking to match the per-superblock inode
list. This takes the global lock out of the picture and reduces the
contention problems to within a single filesystem. This doesn't get
rid of contention as the locks still have global CPU scope, but it
does isolate operations on different superblocks form each other.

Signed-off-by: Dave Chinner 
Signed-off-by: Josef Bacik 
Reviewed-by: Jan Kara 
Reviewed-by: Christoph Hellwig 
Tested-by: Dave Chinner