From: Miklos Szeredi <mszeredi@redhat.com>
To: linux-unionfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH v2 00/35] overlayfs: stack file operations
Date: Mon, 7 May 2018 10:37:32 +0200 [thread overview]
Message-ID: <20180507083807.28792-1-mszeredi@redhat.com> (raw)
[Al, can you please review the vfs affecting patches? ]
Up till now overlayfs didn't stack regular file operations. Instead, when
a file was opened on an overlay, the file from one of the underlying layers
would be opened and any file operations performed would directly go to the
underlying file on a real filesystem.
This works well mostly, but various hacks were added to the VFS to work
around issues with this:
- d_path() and friends
- relatime handling
- file locking
- fsnotify
- writecount handling
There are also issues that are unresolved before this patchset:
- ioctl's that need write access but can be performed on a O_RDONLY fd
- ro/rw inconsistency: file on lower layer opened for read-only will
return stale data on read after copy-up and modification
- ro/rw inconsistency for mmap: file on lower layer mapped shared will
contain stale data after copy-up and modification
This patch series reverts the VFS hacks (with the exception of d_path) and
fixes the unresoved issues. We need to keep d_path related hacks, because
memory maps are still not stacked, yet d_path() should keep working on
vma->vm_file->f_path.
No regressions were observed after running various test suites (xfstests,
ltp, unionmount-testsuite, pjd-fstest).
Performance impact of stacking was found to be minimal. Memory use for
open overlay files increases by about 256bytes or 12% of total (files +
pinned dentries + pinned inodes).
Git tree is here:
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git overlayfs-rorw
Thanks,
Miklos
Changes from v1:
- split out dedupe API cleanup
- update documentation and comments
- clean up directory modification helpers inside overlayfs
- make functions static
- added compat ioctl
- check for upper files in dedupe
- bring back d_real_inode() as a new user just cropped up in 4.17
---
Miklos Szeredi (35):
vfs: add path_open()
vfs: optionally don't account file in nr_files
vfs: add f_op->pre_mmap()
vfs: export vfs_ioctl() to modules
vfs: export vfs_dedupe_file_range_one() to modules
ovl: copy up times
ovl: copy up inode flags
Revert "Revert "ovl: get_write_access() in truncate""
ovl: copy up file size as well
ovl: deal with overlay files in ovl_d_real()
ovl: stack file ops
ovl: add helper to return real file
ovl: add ovl_read_iter()
ovl: add ovl_write_iter()
ovl: add ovl_fsync()
ovl: add ovl_mmap()
ovl: add ovl_fallocate()
ovl: add lsattr/chattr support
ovl: add ovl_fiemap()
ovl: add O_DIRECT support
ovl: add reflink/copyfile/dedup support
vfs: don't open real
ovl: copy-up on MAP_SHARED
vfs: simplify dentry_open()
Revert "ovl: fix may_write_real() for overlayfs directories"
Revert "ovl: don't allow writing ioctl on lower layer"
vfs: fix freeze protection in mnt_want_write_file() for overlayfs
Revert "ovl: fix relatime for directories"
Revert "vfs: update ovl inode before relatime check"
Revert "vfs: add flags to d_real()"
Revert "vfs: do get_write_access() on upper layer of overlayfs"
Partially revert "locks: fix file locking on overlayfs"
Revert "fsnotify: support overlayfs"
vfs: remove open_flags from d_real()
ovl: fix documentation of non-standard behavior
Documentation/filesystems/Locking | 4 +-
Documentation/filesystems/overlayfs.txt | 60 ++--
Documentation/filesystems/vfs.txt | 19 +-
fs/file_table.c | 13 +-
fs/inode.c | 46 +--
fs/internal.h | 17 +-
fs/ioctl.c | 1 +
fs/locks.c | 20 +-
fs/namei.c | 2 +-
fs/namespace.c | 69 +----
fs/open.c | 74 ++---
fs/overlayfs/Kconfig | 21 ++
fs/overlayfs/Makefile | 4 +-
fs/overlayfs/dir.c | 33 ++-
fs/overlayfs/file.c | 506 ++++++++++++++++++++++++++++++++
fs/overlayfs/inode.c | 63 +++-
fs/overlayfs/overlayfs.h | 21 +-
fs/overlayfs/ovl_entry.h | 1 +
fs/overlayfs/super.c | 65 ++--
fs/overlayfs/util.c | 11 +-
fs/read_write.c | 6 +-
fs/xattr.c | 9 +-
include/linux/dcache.h | 15 +-
include/linux/fs.h | 28 +-
include/linux/fsnotify.h | 14 +-
include/uapi/linux/fs.h | 1 -
mm/util.c | 5 +
27 files changed, 824 insertions(+), 304 deletions(-)
create mode 100644 fs/overlayfs/file.c
--
2.14.3
next reply other threads:[~2018-05-07 8:38 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-07 8:37 Miklos Szeredi [this message]
2018-05-07 8:37 ` [PATCH v2 01/35] vfs: add path_open() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 02/35] vfs: optionally don't account file in nr_files Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 03/35] vfs: add f_op->pre_mmap() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 04/35] vfs: export vfs_ioctl() to modules Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 05/35] vfs: export vfs_dedupe_file_range_one() " Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 06/35] ovl: copy up times Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 07/35] ovl: copy up inode flags Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 08/35] Revert "Revert "ovl: get_write_access() in truncate"" Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 09/35] ovl: copy up file size as well Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 10/35] ovl: deal with overlay files in ovl_d_real() Miklos Szeredi
2018-05-07 13:17 ` Vivek Goyal
2018-05-07 8:37 ` [PATCH v2 11/35] ovl: stack file ops Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 12/35] ovl: add helper to return real file Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 13/35] ovl: add ovl_read_iter() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 14/35] ovl: add ovl_write_iter() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 15/35] ovl: add ovl_fsync() Miklos Szeredi
2018-05-08 5:14 ` Amir Goldstein
2018-05-08 14:57 ` Miklos Szeredi
2018-05-08 15:02 ` Amir Goldstein
2018-05-07 8:37 ` [PATCH v2 16/35] ovl: add ovl_mmap() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 17/35] ovl: add ovl_fallocate() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 18/35] ovl: add lsattr/chattr support Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 19/35] ovl: add ovl_fiemap() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 20/35] ovl: add O_DIRECT support Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 21/35] ovl: add reflink/copyfile/dedup support Miklos Szeredi
2018-05-07 20:43 ` Darrick J. Wong
2018-05-08 14:13 ` Miklos Szeredi
2018-05-08 14:38 ` Darrick J. Wong
2018-05-07 8:37 ` [PATCH v2 22/35] vfs: don't open real Miklos Szeredi
2018-05-07 10:27 ` Amir Goldstein
2018-05-07 10:29 ` Miklos Szeredi
2018-05-11 18:54 ` Vivek Goyal
2018-05-11 19:42 ` Vivek Goyal
2018-05-14 13:58 ` Vivek Goyal
2018-05-15 20:42 ` Vivek Goyal
2018-05-14 14:03 ` Daniel Walsh
2018-05-07 8:37 ` [PATCH v2 23/35] ovl: copy-up on MAP_SHARED Miklos Szeredi
2018-05-07 19:28 ` Randy Dunlap
2018-05-08 15:03 ` Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 24/35] vfs: simplify dentry_open() Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 25/35] Revert "ovl: fix may_write_real() for overlayfs directories" Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 26/35] Revert "ovl: don't allow writing ioctl on lower layer" Miklos Szeredi
2018-05-07 8:37 ` [PATCH v2 27/35] vfs: fix freeze protection in mnt_want_write_file() for overlayfs Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 28/35] Revert "ovl: fix relatime for directories" Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 29/35] Revert "vfs: update ovl inode before relatime check" Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 30/35] Revert "vfs: add flags to d_real()" Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 31/35] Revert "vfs: do get_write_access() on upper layer of overlayfs" Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 32/35] Partially revert "locks: fix file locking on overlayfs" Miklos Szeredi
2018-05-08 15:15 ` Jeff Layton
2018-05-07 8:38 ` [PATCH v2 33/35] Revert "fsnotify: support overlayfs" Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 34/35] vfs: remove open_flags from d_real() Miklos Szeredi
2018-05-07 8:38 ` [PATCH v2 35/35] ovl: fix documentation of non-standard behavior Miklos Szeredi
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