summaryrefslogtreecommitdiffstats
path: root/fs/overlayfs/dir.c
AgeCommit message (Collapse)AuthorFilesLines
2020-09-02ovl: pass ovl_fs down to functions accessing private xattrsMiklos Szeredi1-1/+1
This paves the way for optionally using the "user.overlay." xattr namespace. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-06-02ovl: initialize OVL_UPPERDATA in ovl_lookup()Vivek Goyal1-0/+2
Currently ovl_get_inode() initializes OVL_UPPERDATA flag and for that it has to call ovl_check_metacopy_xattr() and check if metacopy xattr is present or not. yangerkun reported sometimes underlying filesystem might return -EIO and in that case error handling path does not cleanup properly leading to various warnings. Run generic/461 with ext4 upper/lower layer sometimes may trigger the bug as below(linux 4.19): [ 551.001349] overlayfs: failed to get metacopy (-5) [ 551.003464] overlayfs: failed to get inode (-5) [ 551.004243] overlayfs: cleanup of 'd44/fd51' failed (-5) [ 551.004941] overlayfs: failed to get origin (-5) [ 551.005199] ------------[ cut here ]------------ [ 551.006697] WARNING: CPU: 3 PID: 24674 at fs/inode.c:1528 iput+0x33b/0x400 ... [ 551.027219] Call Trace: [ 551.027623] ovl_create_object+0x13f/0x170 [ 551.028268] ovl_create+0x27/0x30 [ 551.028799] path_openat+0x1a35/0x1ea0 [ 551.029377] do_filp_open+0xad/0x160 [ 551.029944] ? vfs_writev+0xe9/0x170 [ 551.030499] ? page_counter_try_charge+0x77/0x120 [ 551.031245] ? __alloc_fd+0x160/0x2a0 [ 551.031832] ? do_sys_open+0x189/0x340 [ 551.032417] ? get_unused_fd_flags+0x34/0x40 [ 551.033081] do_sys_open+0x189/0x340 [ 551.033632] __x64_sys_creat+0x24/0x30 [ 551.034219] do_syscall_64+0xd5/0x430 [ 551.034800] entry_SYSCALL_64_after_hwframe+0x44/0xa9 One solution is to improve error handling and call iget_failed() if error is encountered. Amir thinks that this path is little intricate and there is not real need to check and initialize OVL_UPPERDATA in ovl_get_inode(). Instead caller of ovl_get_inode() can initialize this state. And this will avoid double checking of metacopy xattr lookup in ovl_lookup() and ovl_get_inode(). OVL_UPPERDATA is inode flag. So I was little concerned that initializing it outside ovl_get_inode() might have some races. But this is one way transition. That is once a file has been fully copied up, it can't go back to metacopy file again. And that seems to help avoid races. So as of now I can't see any races w.r.t OVL_UPPERDATA being set wrongly. So move settingof OVL_UPPERDATA inside the callers of ovl_get_inode(). ovl_obtain_alias() already does it. So only two callers now left are ovl_lookup() and ovl_instantiate(). Reported-by: yangerkun <yangerkun@huawei.com> Suggested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-13ovl: whiteout inode sharingChengguang Xu1-12/+37
Share inode with different whiteout files for saving inode and speeding up delete operation. If EMLINK is encountered when linking a shared whiteout, create a new one. In case of any other error, disable sharing for this super block. Note: ofs->whiteout is protected by inode lock on workdir. Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-03-27ovl: fix WARN_ON nlink drop to zeroMiklos Szeredi1-2/+24
Changes to underlying layers should not cause WARN_ON(), but this repro does: mkdir w l u mnt sudo mount -t overlay -o workdir=w,lowerdir=l,upperdir=u overlay mnt touch mnt/h ln u/h u/k rm -rf mnt/k rm -rf mnt/h dmesg ------------[ cut here ]------------ WARNING: CPU: 1 PID: 116244 at fs/inode.c:302 drop_nlink+0x28/0x40 After upper hardlinks were added while overlay is mounted, unlinking all overlay hardlinks drops overlay nlink to zero before all upper inodes are unlinked. After unlink/rename prevent i_nlink from going to zero if there are still hashed aliases (i.e. cached hard links to the victim) remaining. Reported-by: Phasip <phasip@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-03-17ovl: check if upper fs supports RENAME_WHITEOUTAmir Goldstein1-1/+1
As with other required upper fs features, we only warn if support is missing to avoid breaking existing sub-optimal setups. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-03-17ovl: decide if revalidate needed on a per-dentry basisMiklos Szeredi1-0/+3
Allow completely skipping ->revalidate() on a per-dentry basis, in case the underlying layers used for a dentry do not themselves have ->revalidate(). E.g. negative overlay dentry has no underlying layers, hence revalidate is unnecessary. Or if lower layer is remote but overlay dentry is pure-upper, then can skip revalidate. The following places need to update whether the dentry needs revalidate or not: - fill-super (root dentry) - lookup - create - fh_to_dentry Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-01-22ovl: use pr_fmt auto generate prefixlijiazi1-5/+5
Use pr_fmt auto generate "overlayfs: " prefix. Signed-off-by: lijiazi <lijiazi@xiaomi.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-12-10ovl: relax WARN_ON() on rename to selfAmir Goldstein1-1/+1
In ovl_rename(), if new upper is hardlinked to old upper underneath overlayfs before upper dirs are locked, user will get an ESTALE error and a WARN_ON will be printed. Changes to underlying layers while overlayfs is mounted may result in unexpected behavior, but it shouldn't crash the kernel and it shouldn't trigger WARN_ON() either, so relax this WARN_ON(). Reported-by: syzbot+bb1836a212e69f8e201a@syzkaller.appspotmail.com Fixes: 804032fabb3b ("ovl: don't check rename to self") Cc: <stable@vger.kernel.org> # v4.9+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-06-21Merge tag 'spdx-5.2-rc6' of ↵Linus Torvalds1-4/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx Pull still more SPDX updates from Greg KH: "Another round of SPDX updates for 5.2-rc6 Here is what I am guessing is going to be the last "big" SPDX update for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates that were "easy" to determine by pattern matching. The ones after this are going to be a bit more difficult and the people on the spdx list will be discussing them on a case-by-case basis now. Another 5000+ files are fixed up, so our overall totals are: Files checked: 64545 Files with SPDX: 45529 Compared to the 5.1 kernel which was: Files checked: 63848 Files with SPDX: 22576 This is a huge improvement. Also, we deleted another 20000 lines of boilerplate license crud, always nice to see in a diffstat" * tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485 ...
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18ovl: fix typo in MODULE_PARM_DESCNicolas Schier1-1/+1
Change first argument to MODULE_PARM_DESC() calls, that each of them matched the actual module parameter name. The matching results in changing (the 'parm' section from) the output of `modinfo overlay` from: parm: ovl_check_copy_up:Obsolete; does nothing parm: redirect_max:ushort parm: ovl_redirect_max:Maximum length of absolute redirect xattr value parm: redirect_dir:bool parm: ovl_redirect_dir_def:Default to on or off for the redirect_dir feature parm: redirect_always_follow:bool parm: ovl_redirect_always_follow:Follow redirects even if redirect_dir feature is turned off parm: index:bool parm: ovl_index_def:Default to on or off for the inodes index feature parm: nfs_export:bool parm: ovl_nfs_export_def:Default to on or off for the NFS export feature parm: xino_auto:bool parm: ovl_xino_auto_def:Auto enable xino feature parm: metacopy:bool parm: ovl_metacopy_def:Default to on or off for the metadata only copy up feature into: parm: check_copy_up:Obsolete; does nothing parm: redirect_max:Maximum length of absolute redirect xattr value (ushort) parm: redirect_dir:Default to on or off for the redirect_dir feature (bool) parm: redirect_always_follow:Follow redirects even if redirect_dir feature is turned off (bool) parm: index:Default to on or off for the inodes index feature (bool) parm: nfs_export:Default to on or off for the NFS export feature (bool) parm: xino_auto:Auto enable xino feature (bool) parm: metacopy:Default to on or off for the metadata only copy up feature (bool) Signed-off-by: Nicolas Schier <n.schier@avm.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-05-08ovl: relax WARN_ON() for overlapping layers use caseAmir Goldstein1-1/+1
This nasty little syzbot repro: https://syzkaller.appspot.com/x/repro.syz?x=12c7a94f400000 Creates overlay mounts where the same directory is both in upper and lower layers. Simplified example: mkdir foo work mount -t overlay none foo -o"lowerdir=.,upperdir=foo,workdir=work" The repro runs several threads in parallel that attempt to chdir into foo and attempt to symlink/rename/exec/mkdir the file bar. The repro hits a WARN_ON() I placed in ovl_instantiate(), which suggests that an overlay inode already exists in cache and is hashed by the pointer of the real upper dentry that ovl_create_real() has just created. At the point of the WARN_ON(), for overlay dir inode lock is held and upper dir inode lock, so at first, I did not see how this was possible. On a closer look, I see that after ovl_create_real(), because of the overlapping upper and lower layers, a lookup by another thread can find the file foo/bar that was just created in upper layer, at overlay path foo/foo/bar and hash the an overlay inode with the new real dentry as lower dentry. This is possible because the overlay directory foo/foo is not locked and the upper dentry foo/bar is in dcache, so ovl_lookup() can find it without taking upper dir inode shared lock. Overlapping layers is considered a wrong setup which would result in unexpected behavior, but it shouldn't crash the kernel and it shouldn't trigger WARN_ON() either, so relax this WARN_ON() and leave a pr_warn() instead to cover all cases of failure to get an overlay inode. The error returned from failure to insert new inode to cache with inode_insert5() was changed to -EEXIST, to distinguish from the error -ENOMEM returned on failure to get/allocate inode with iget5_locked(). Reported-by: syzbot+9c69c282adc4edd2b540@syzkaller.appspotmail.com Fixes: 01b39dcc9568 ("ovl: use inode_insert5() to hash a newly...") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-11-19ovl: fix missing override creds in link of a metacopy upperAmir Goldstein1-1/+13
Theodore Ts'o reported a v4.19 regression with docker-dropbox: https://marc.info/?l=linux-fsdevel&m=154070089431116&w=2 "I was rebuilding my dropbox Docker container, and it failed in 4.19 with the following error: ... dpkg: error: error creating new backup file \ '/var/lib/dpkg/status-old': Invalid cross-device link" The problem did not reproduce with metacopy feature disabled. The error was caused by insufficient credentials to set "trusted.overlay.redirect" xattr on link of a metacopy file. Reproducer: echo Y > /sys/module/overlay/parameters/redirect_dir echo Y > /sys/module/overlay/parameters/metacopy cd /tmp mkdir l u w m chmod 777 l u touch l/foo ln l/foo l/link chmod 666 l/foo mount -t overlay none -olowerdir=l,upperdir=u,workdir=w m su fsgqa ln m/foo m/bar [ 21.455823] overlayfs: failed to set redirect (-1) ln: failed to create hard link 'm/bar' => 'm/foo':\ Invalid cross-device link Reported-by: Theodore Y. Ts'o <tytso@mit.edu> Reported-by: Maciej Zięba <maciekz82@gmail.com> Fixes: 4120fe64dce4 ("ovl: Set redirect on upper inode when it is linked") Cc: <stable@vger.kernel.org> # v4.19 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-31ovl: check whiteout in ovl_create_over_whiteout()Miklos Szeredi1-0/+4
Kaixuxia repors that it's possible to crash overlayfs by removing the whiteout on the upper layer before creating a directory over it. This is a reproducer: mkdir lower upper work merge touch lower/file mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge rm merge/file ls -al merge/file rm upper/file ls -al merge/ mkdir merge/file Before commencing with a vfs_rename(..., RENAME_EXCHANGE) verify that the lookup of "upper" is positive and is a whiteout, and return ESTALE otherwise. Reported by: kaixuxia <xiakaixu1987@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: e9be9d5e76e3 ("overlay filesystem") Cc: <stable@vger.kernel.org> # v3.18
2018-10-26ovl: using posix_acl_xattr_size() to get size instead of posix_acl_to_xattr()Chengguang Xu1-3/+2
There is no functional change but it seems better to get size by calling posix_acl_xattr_size() instead of calling posix_acl_to_xattr() with NULL buffer argument. Additionally, remove unnecessary assignments. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-26ovl: remove the 'locked' argument of ovl_nlink_{start,end}Amir Goldstein1-10/+11
It just makes the interface strange without adding any significant value. The only case where locked is false and return value is 0 is in ovl_rename() when new is negative, so handle that case explicitly in ovl_rename(). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-26ovl: fix recursive oi->lock in ovl_link()Amir Goldstein1-0/+4
linking a non-copied-up file into a non-copied-up parent results in a nested call to mutex_lock_interruptible(&oi->lock). Fix this by copying up target parent before ovl_nlink_start(), same as done in ovl_rename(). ~/unionmount-testsuite$ ./run --ov -s ~/unionmount-testsuite$ ln /mnt/a/foo100 /mnt/a/dir100/ WARNING: possible recursive locking detected -------------------------------------------- ln/1545 is trying to acquire lock: 00000000bcce7c4c (&ovl_i_lock_key[depth]){+.+.}, at: ovl_copy_up_start+0x28/0x7d but task is already holding lock: 0000000026d73d5b (&ovl_i_lock_key[depth]){+.+.}, at: ovl_nlink_start+0x3c/0xc1 [SzM: this seems to be a false positive, but doing the copy-up first is harmless and removes the lockdep splat] Reported-by: syzbot+3ef5c0d1a5cb0b21e6be@syzkaller.appspotmail.com Fixes: 5f8415d6b87e ("ovl: persistent overlay inode nlink for...") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-08-22ovl: set I_CREATING on inode being createdMiklos Szeredi1-0/+4
...otherwise there will be list corruption due to inode_sb_list_add() being called for inode already on the sb list. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: e950564b97fd ("vfs: don't evict uninitialized inode") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-20ovl: Set redirect on upper inode when it is linkedVivek Goyal1-0/+8
When we create a hardlink to a metacopy upper file, first the redirect on that inode. Path based lookup will not work with newly created link and redirect will solve that issue. Also use absolute redirect as two hardlinks could be in different directores and relative redirect will not work. I have not put any additional locking around setting redirects while introducing redirects for non-dir files. For now it feels like existing locking is sufficient. If that's not the case, we will have add more locking. Following is my rationale about why do I think current locking seems ok. Basic problem for non-dir files is that more than on dentry could be pointing to same inode and in theory only relying on dentry based locks (d->d_lock) did not seem sufficient. We set redirect upon rename and upon link creation. In both the paths for non-dir file, VFS locks both source and target inodes (->i_rwsem). That means vfs rename and link operations on same source and target can't he happening in parallel (Even if there are multiple dentries pointing to same inode). So that probably means that at a time on an inode, only one call of ovl_set_redirect() could be working and we don't need additional locking in ovl_set_redirect(). ovl_inode->redirect is initialized only when inode is created new. That means it should not race with any other path and setting ovl_inode->redirect should be fine. Reading of ovl_inode->redirect happens in ovl_get_redirect() path. And this called only in ovl_set_redirect(). And ovl_set_redirect() already seemed to be protected using ->i_rwsem. That means ovl_set_redirect() and ovl_get_redirect() on source/target inode should not make progress in parallel and is mutually exclusive. Hence no additional locking required. Now, only case where ovl_set_redirect() and ovl_get_redirect() could race seems to be case of absolute redirects where ovl_get_redirect() has to travel up the tree. In that case we already take d->d_lock and that should be sufficient as directories will not have multiple dentries pointing to same inode. So given VFS locking and current usage of redirect, current locking around redirect seems to be ok for non-dir as well. Once we have the logic to remove redirect when metacopy file gets copied up, then we probably will need additional locking. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-20ovl: Set redirect on metacopy files upon renameVivek Goyal1-20/+46
Set redirect on metacopy files upon rename. This will help find data dentry in lower dirs. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-18ovl: copy up timesMiklos Szeredi1-7/+24
Copy up mtime and ctime to overlay inode after times in real object are modified. Be careful not to dirty cachelines when not necessary. This is in preparation for moving overlay functionality out of the VFS. This patch shouldn't have any observable effect. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: use inode_insert5() to hash a newly created inodeAmir Goldstein1-10/+49
Currently, there is a small window where ovl_obtain_alias() can race with ovl_instantiate() and create two different overlay inodes with the same underlying real non-dir non-hardlink inode. The race requires an adversary to guess the file handle of the yet to be created upper inode and decode the guessed file handle after ovl_creat_real(), but before ovl_instantiate(). This race does not affect overlay directory inodes, because those are decoded via ovl_lookup_real() and not with ovl_obtain_alias(). This patch fixes the race, by using inode_insert5() to add a newly created inode to cache. If the newly created inode apears to already exist in cache (hashed by the same real upper inode), we instantiate the dentry with the old inode and drop the new inode, instead of silently not hashing the new inode. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: return EIO on internal errorMiklos Szeredi1-1/+1
EIO better represents an internal error than ENOENT. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: make ovl_create_real() cope with vfs_mkdir() safelyAl Viro1-1/+33
vfs_mkdir() may succeed and leave the dentry passed to it unhashed and negative. ovl_create_real() is the last caller breaking when that happens. [amir: split re-factoring of ovl_create_temp() to prep patch add comment about unhashed dir after mkdir add pr_warn() if mkdir succeeds and lookup fails] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: create helper ovl_create_temp()Amir Goldstein1-4/+9
Also used ovl_create_temp() in ovl_create_index() instead of calling ovl_do_mkdir() directly, so now all callers of ovl_do_mkdir() are routed through ovl_create_real(), which paves the way for Al's fix for non-hashed result from vfs_mkdir(). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: return dentry from ovl_create_real()Miklos Szeredi1-32/+30
Al Viro suggested to simplify callers of ovl_create_real() by returning the created dentry (or ERR_PTR) from ovl_create_real(). Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: struct cattr cleanupsAmir Goldstein1-24/+21
* Rename to ovl_cattr * Fold ovl_create_real() hardlink argument into struct ovl_cattr * Create macro OVL_CATTR() to initialize struct ovl_cattr from mode Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: strip debug argument from ovl_do_ helpersAmir Goldstein1-10/+10
It did not prove to be useful. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-05-31ovl: remove WARN_ON() real inode attributes mismatchAmir Goldstein1-7/+0
Overlayfs should cope with online changes to underlying layer without crashing the kernel, which is what xfstest overlay/019 checks. This test may sometimes trigger WARN_ON() in ovl_create_or_link() when linking an overlay inode that has been changed on underlying layer. Remove those WARN_ON() to prevent the stress test from failing. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-01-24ovl: whiteout index when union nlink drops to zeroAmir Goldstein1-23/+35
With NFS export feature enabled, when overlay inode nlink drops to zero, instead of removing the index entry, replace it with a whiteout index entry. This is needed for NFS export in order to prevent future open by handle from opening the lower file directly. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-01-19ovl: take lower dir inode mutex outside upper sb_writers lockAmir Goldstein1-65/+52
The functions ovl_lower_positive() and ovl_check_empty_dir() both take inode mutex on the real lower dir under ovl_want_write() which takes the upper_mnt sb_writers lock. While this is not a clear locking order or layering violation, it creates an undesired lock dependency between two unrelated layers for no good reason. This lock dependency materializes to a false(?) positive lockdep warning when calling rmdir() on a nested overlayfs, where both nested and underlying overlayfs both use the same fs type as upper layer. rmdir() on the nested overlayfs creates the lock chain: sb_writers of upper_mnt (e.g. tmpfs) in ovl_do_remove() ovl_i_mutex_dir_key[] of lower overlay dir in ovl_lower_positive() rmdir() on the underlying overlayfs creates the lock chain in reverse order: ovl_i_mutex_dir_key[] of lower overlay dir in vfs_rmdir() sb_writers of nested upper_mnt (e.g. tmpfs) in ovl_do_remove() To rid of the unneeded locking dependency, move both ovl_lower_positive() and ovl_check_empty_dir() to before ovl_want_write() in rmdir() and rename() implementation. This change spreads the pieces of ovl_check_empty_and_clear() directly inside the rmdir()/rename() implementations so the helper is no longer needed and removed. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-12-14ovl: fix overlay: warning prefixAmir Goldstein1-1/+2
Conform two stray warning messages to the standard overlayfs: prefix. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: update cache version of impure parent on renameAmir Goldstein1-3/+4
ovl_rename() updates dir cache version for impure old parent if an entry with copy up origin is moved into old parent, but it did not update cache version if the entry moved out of old parent has a copy up origin. [SzM] Same for new dir: we updated the version if an entry with origin was moved in, but not if an entry with origin was moved out. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: fix rmdir problem on non-merge dir with origin xattrzhangyi (F)1-3/+10
An "origin && non-merge" upper dir may have leftover whiteouts that were created in past mount. overlayfs does no clear this dir when we delete it, which may lead to rmdir fail or temp file left in workdir. Simple reproducer: mkdir lower upper work merge mkdir -p lower/dir touch lower/dir/a mount -t overlay overlay -olowerdir=lower,upperdir=upper,\ workdir=work merge rm merge/dir/a umount merge rm -rf lower/* touch lower/dir (*) mount -t overlay overlay -olowerdir=lower,upperdir=upper,\ workdir=work merge rm -rf merge/dir Syslog dump: overlayfs: cleanup of 'work/#7' failed (-39) (*): if we do not create the regular file, the result is different: rm: cannot remove "dir/": Directory not empty This patch adds a check for the case of non-merge dir that may contain whiteouts, and calls ovl_check_empty_dir() to check and clear whiteouts from upper dir when an empty dir is being deleted. [amir: split patch from ovl_check_empty_dir() cleanup rename ovl_is_origin() to ovl_may_have_whiteouts() check OVL_WHITEOUTS flag instead of checking origin xattr] Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: simplify ovl_check_empty_and_clear()zhangyi (F)1-3/+2
Filter out non-whiteout non-upper entries from list of merge dir entries while checking if merge dir is empty in ovl_check_empty_dir(). The remaining work for ovl_clear_empty() is to clear all entries on the list. [amir: split patch from rmdir bug fix] Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-05ovl: fix missing unlock_rename() in ovl_do_copy_up()Amir Goldstein1-20/+0
Use the ovl_lock_rename_workdir() helper which requires unlock_rename() only on lock success. Fixes: ("fd210b7d67ee ovl: move copy up lock out") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-13mm: treewide: remove GFP_TEMPORARY allocation flagMichal Hocko1-1/+1
GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's primary motivation was to allow users to tell that an allocation is short lived and so the allocator can try to place such allocations close together and prevent long term fragmentation. As much as this sounds like a reasonable semantic it becomes much less clear when to use the highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the context holding that memory sleep? Can it take locks? It seems there is no good answer for those questions. The current implementation of GFP_TEMPORARY is basically GFP_KERNEL | __GFP_RECLAIMABLE which in itself is tricky because basically none of the existing caller provide a way to reclaim the allocated memory. So this is rather misleading and hard to evaluate for any benefits. I have checked some random users and none of them has added the flag with a specific justification. I suspect most of them just copied from other existing users and others just thought it might be a good idea to use without any measuring. This suggests that GFP_TEMPORARY just motivates for cargo cult usage without any reasoning. I believe that our gfp flags are quite complex already and especially those with highlevel semantic should be clearly defined to prevent from confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and replace all existing users to simply use GFP_KERNEL. Please note that SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and so they will be placed properly for memory fragmentation prevention. I can see reasons we might want some gfp flag to reflect shorterm allocations but I propose starting from a clear semantic definition and only then add users with proper justification. This was been brought up before LSF this year by Matthew [1] and it turned out that GFP_TEMPORARY really doesn't have a clear semantic. It seems to be a heuristic without any measured advantage for most (if not all) its current users. The follow up discussion has revealed that opinions on what might be temporary allocation differ a lot between developers. So rather than trying to tweak existing users into a semantic which they haven't expected I propose to simply remove the flag and start from scratch if we really need a semantic for short term allocations. [1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org [akpm@linux-foundation.org: fix typo] [akpm@linux-foundation.org: coding-style fixes] [sfr@canb.auug.org.au: drm/i915: fix up] Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Neil Brown <neilb@suse.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-27ovl: constant d_ino for non-merge dirsMiklos Szeredi1-5/+6
Impure directories are ones which contain objects with origins (i.e. those that have been copied up). These are relevant to readdir operation only because of the d_ino field, no other transformation is necessary. Also a directory can become impure between two getdents(2) calls. This patch creates a cache for impure directories. Unlike the cache for merged directories, this one only contains entries with origin and is not refcounted but has a its lifetime tied to that of the dentry. Similarly to the merged cache, the impure cache is invalidated based on a version number. This version number is incremented when an entry with origin is added or removed from the directory. If the cache is empty, then the impure xattr is removed from the directory. This patch also fixes up handling of d_ino for the ".." entry if the parent directory is merged. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: mark parent impure on ovl_link()Amir Goldstein1-4/+18
When linking a file with copy up origin into a new parent, mark the new parent dir "impure". Fixes: ee1d6d37b6b8 ("ovl: mark upper dir with type origin entries "impure"") Cc: <stable@vger.kernel.org> # v4.12 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: persistent overlay inode nlink for indexed inodesAmir Goldstein1-2/+17
With inodes index enabled, an overlay inode nlink counts the union of upper and non-covered lower hardlinks. During the lifetime of a non-pure upper inode, the following nlink modifying operations can happen: 1. Lower hardlink copy up 2. Upper hardlink created, unlinked or renamed over 3. Lower hardlink whiteout or renamed over For the first, copy up case, the union nlink does not change, whether the operation succeeds or fails, but the upper inode nlink may change. Therefore, before copy up, we store the union nlink value relative to the lower inode nlink in the index inode xattr trusted.overlay.nlink. For the second, upper hardlink case, the union nlink should be incremented or decremented IFF the operation succeeds, aligned with nlink change of the upper inode. Therefore, before link/unlink/rename, we store the union nlink value relative to the upper inode nlink in the index inode. For the last, lower cover up case, we simplify things by preceding the whiteout or cover up with copy up. This makes sure that there is an index upper inode where the nlink xattr can be stored before the copied up upper entry is unlink. Return the overlay inode nlinks for indexed upper inodes on stat(2). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: add flag for upper in ovl_entryMiklos Szeredi1-0/+1
For rename, we need to ensure that an upper alias exists for hard links before attempting the operation. Introduce a flag in ovl_entry to track the state of the upper alias. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: cleanup bad and stale index entries on mountAmir Goldstein1-1/+3
Bad index entries are entries whose name does not match the origin file handle stored in trusted.overlay.origin xattr. Bad index entries could be a result of a system power off in the middle of copy up. Stale index entries are entries whose origin file handle is stale. Stale index entries could be a result of copying layers or removing lower entries while the overlay is not mounted. The case of copying layers should be detected earlier by the verification of upper root dir origin and index dir origin. Both bad and stale index entries are detected and removed on mount. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: move __upperdentry to ovl_inodeMiklos Szeredi1-4/+4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: compare inodesMiklos Szeredi1-4/+9
When checking for consistency in directory operations (unlink, rename, etc.) match inodes not dentries. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: fix nlink leak in ovl_rename()Amir Goldstein1-0/+7
This patch fixes an overlay inode nlink leak in the case where ovl_rename() renames over a non-dir. This is not so critical, because overlay inode doesn't rely on nlink dropping to zero for inode deletion. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-29ovl: mark upper merge dir with type origin entries "impure"Amir Goldstein1-26/+5
An upper dir is marked "impure" to let ovl_iterate() know that this directory may contain non pure upper entries whose d_ino may need to be read from the origin inode. We already mark a non-merge dir "impure" when moving a non-pure child entry inside it, to let ovl_iterate() know not to iterate the non-merge dir directly. Mark also a merge dir "impure" when moving a non-pure child entry inside it and when copying up a child entry inside it. This can be used to optimize ovl_iterate() to perform a "pure merge" of upper and lower directories, merging the content of the directories, without having to read d_ino from origin inodes. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-19ovl: mark upper dir with type origin entries "impure"Amir Goldstein1-0/+45
When moving a merge dir or non-dir with copy up origin into a non-merge upper dir (a.k.a pure upper dir), we are marking the target parent dir "impure". ovl_iterate() iterates pure upper dirs directly, because there is no need to filter out whiteouts and merge dir content with lower dir. But for the case of an "impure" upper dir, ovl_iterate() will not be able to iterate the real upper dir directly, because it will need to lookup the origin inode and use it to fill d_ino. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-19ovl: remove unused arg from ovl_lookup_temp()Miklos Szeredi1-4/+4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-19ovl: handle rename when upper doesn't support xattrAmir Goldstein1-10/+19
On failure to set opaque/redirect xattr on rename, skip setting xattr and return -EXDEV. On failure to set opaque xattr when creating a new directory, -EIO is returned instead of -EOPNOTSUPP. Any failure to set those xattr will be recorded in super block and then setting any xattr on upper won't be attempted again. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-05ovl: persistent inode numbers for upper hardlinksAmir Goldstein1-0/+3
An upper type non directory dentry that is a copy up target should have a reference to its lower copy up origin. There are three ways for an upper type dentry to be instantiated: 1. A lower type dentry that is being copied up 2. An entry that is found in upper dir by ovl_lookup() 3. A negative dentry is hardlinked to an upper type dentry In the first case, the lower reference is set before copy up. In the second case, the lower reference is found by ovl_lookup(). In the last case of hardlinked upper dentry, it is not easy to update the lower reference of the negative dentry. Instead, drop the newly hardlinked negative dentry from dcache and let the next access call ovl_lookup() to find its lower reference. This makes sure that the inode number reported by stat(2) after the hardlink is created is the same inode number that will be reported by stat(2) after mount cycle, which is the inode number of the lower copy up origin of the hardlink source. NOTE that this does not fix breaking of lower hardlinks on copy up, but only fixes the case of lower nlink == 1, whose upper copy up inode is hardlinked in upper dir. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 08:37:54 +0000