summaryrefslogtreecommitdiffstats
path: root/fs/quota/dquot.c
AgeCommit message (Collapse)AuthorFilesLines
2018-06-20quota: Cleanup list iteration in dqcache_shrink_scan()Jan Kara1-5/+2
Use list_first_entry() and list_empty() instead of opencoded variants. Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-06-20quota: reclaim least recently used dquotsGreg Thelen1-2/+2
The dquots in the free_dquots list are not reclaimed in LRU way. put_dquot_last() puts entries to the tail and dqcache_shrink_scan() frees from the tail. Free unreferenced dquots in LRU order because it seems more reasonable than freeing most recently used. Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Jan Kara <jack@suse.cz>
2018-04-09fs: quota: Replace GFP_ATOMIC with GFP_KERNEL in dquot_initJia-Ju Bai1-1/+1
dquot_init() is never called in atomic context. This function is only set as a parameter of fs_initcall(). Despite never getting called from atomic context, dquot_init() calls __get_free_pages() with GFP_ATOMIC, which waits busily for allocation. GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, to avoid busy waiting and improve the possibility of sucessful allocation. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-11-29quota: Check for register_shrinker() failure.Tetsuo Handa1-1/+2
register_shrinker() might return -ENOMEM error since Linux 3.12. Call panic() as with other failure checks in this function if register_shrinker() failed. Fixes: 1d3d4437eae1 ("vmscan: per-node deferred work") Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Jan Kara <jack@suse.com> Cc: Michal Hocko <mhocko@suse.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-11-28quota: propagate error from __dquot_initializeChao Yu1-6/+13
In commit 6184fc0b8dd7 ("quota: Propagate error from ->acquire_dquot()"), we have propagated error from __dquot_initialize to caller, but we forgot to handle such error in add_dquot_ref(), so, currently, during quota accounting information initialization flow, if we failed for some of inodes, we just ignore such error, and do account for others, which is not a good implementation. In this patch, we choose to let user be aware of such error, so after turning on quota successfully, we can make sure all inodes disk usage can be accounted, which will be more reasonable. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-11-14Merge branch 'for_linus' of ↵Linus Torvalds1-3/+10
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota, ext2, isofs and udf fixes from Jan Kara: - two small quota error handling fixes - two isofs fixes for architectures with signed char - several udf block number overflow and signedness fixes - ext2 rework of mount option handling to avoid GFP_KERNEL allocation with spinlock held - ... it also contains a patch to implement auditing of responses to fanotify permission events. That should have been in the fanotify pull request but I mistakenly merged that patch into a wrong branch and noticed only now at which point I don't think it's worth rebasing and redoing. * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: quota: be aware of error from dquot_initialize quota: fix potential infinite loop isofs: use unsigned char types consistently isofs: fix timestamps beyond 2027 udf: Fix some sign-conversion warnings udf: Fix signed/unsigned format specifiers udf: Fix 64-bit sign extension issues affecting blocks > 0x7FFFFFFF udf: Remove some outdate references from documentation udf: Avoid overflow when session starts at large offset ext2: Fix possible sleep in atomic during mount option parsing ext2: Parse mount options into a dedicated structure audit: Record fanotify access control decisions
2017-11-14Merge udf, isofs, quota, ext2 changes for 4.15-rc1.Jan Kara1-3/+10
2017-11-13quota: be aware of error from dquot_initializeChao Yu1-1/+1
Commit 6184fc0b8dd7 ("quota: Propagate error from ->acquire_dquot()") missed to handle error from dquot_initialize in dquot_file_open, fix it. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01quota: fix potential infinite loopzhangyi (F)1-2/+9
In dquot_writeback_dquots(), we write back dquot from dirty dquots list. There is a potential infinite loop if ->write_dquot() failure and forget remove dquot from the list. This patch clear dirty bit anyway to avoid it. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-10-10quota: Generate warnings for DQUOT_SPACE_NOFAIL allocationsJan Kara1-11/+16
Eryu has reported that since commit 7b9ca4c61bc2 "quota: Reduce contention on dq_data_lock" test generic/233 occasionally fails. This is caused by the fact that since that commit we don't generate warning and set grace time for quota allocations that have DQUOT_SPACE_NOFAIL set (these are for example some metadata allocations in ext4). We need these allocations to behave regularly wrt warning generation and grace time setting so fix the code to return to the original behavior. Reported-and-tested-by: Eryu Guan <eguan@redhat.com> CC: stable@vger.kernel.org Fixes: 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac Signed-off-by: Jan Kara <jack@suse.cz>
2017-09-18quota: add missing lock into __dquot_transfer()Konstantin Khlebnikov1-0/+2
Lock dq_dqb_lock around dquot_decr_inodes() Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: 7b9ca4c61bc2 ("quota: Reduce contention on dq_data_lock") Signed-off-by: Jan Kara <jack@suse.cz>
2017-09-07Merge branch 'quota_scaling' of ↵Linus Torvalds1-245/+259
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota scaling updates from Jan Kara: "This contains changes to make the quota subsystem more scalable. Reportedly it improves number of files created per second on ext4 filesystem on fast storage by about a factor of 2x" * 'quota_scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (28 commits) quota: Add lock annotations to struct members quota: Reduce contention on dq_data_lock fs: Provide __inode_get_bytes() quota: Inline dquot_[re]claim_reserved_space() into callsite quota: Inline inode_{incr,decr}_space() into callsites quota: Inline functions into their callsites ext4: Disable dirty list tracking of dquots when journalling quotas quota: Allow disabling tracking of dirty dquots in a list quota: Remove dq_wait_unused from dquot quota: Move locking into clear_dquot_dirty() quota: Do not dirty bad dquots quota: Fix possible corruption of dqi_flags quota: Propagate ->quota_read errors from v2_read_file_info() quota: Fix error codes in v2_read_file_info() quota: Push dqio_sem down to ->read_file_info() quota: Push dqio_sem down to ->write_file_info() quota: Push dqio_sem down to ->get_next_id() quota: Push dqio_sem down to ->release_dqblk() quota: Remove locking for writing to the old quota format quota: Do not acquire dqio_sem for dquot overwrites in v2 format ...
2017-08-17quota: Reduce contention on dq_data_lockJan Kara1-117/+170
dq_data_lock is currently used to protect all modifications of quota accounting information, consistency of quota accounting on the inode, and dquot pointers from inode. As a result contention on the lock can be pretty heavy. Reduce the contention on the lock by protecting quota accounting information by a new dquot->dq_dqb_lock and consistency of quota accounting with inode usage by inode->i_lock. This change reduces time to create 500000 files on ext4 on ramdisk by 50 different processes in separate directories by 6% when user quota is turned on. When those 50 processes belong to 50 different users, the improvement is about 9%. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Inline dquot_[re]claim_reserved_space() into callsiteJan Kara1-25/+16
dquot_claim_reserved_space() and dquot_reclaim_reserved_space() have only a single callsite. Inline them there. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Inline inode_{incr,decr}_space() into callsitesJan Kara1-27/+28
inode_incr_space() and inode_decr_space() have only two callsites. Inline them there as that will make locking changes simpler. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Inline functions into their callsitesJan Kara1-44/+28
inode_add_rsv_space() and inode_sub_rsv_space() had only one callsite. Inline them there directly. inode_claim_rsv_space() and inode_reclaim_rsv_space() had two callsites so inline them there as well. This will simplify further locking changes. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Allow disabling tracking of dirty dquots in a listJan Kara1-0/+6
Filesystems that are journalling quotas generally don't need tracking of dirty dquots in a list since forcing a transaction commit flushes all quotas anyway. Allow filesystem to say it doesn't want dquots to be tracked as it reduces contention on the dq_list_lock. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Remove dq_wait_unused from dquotJan Kara1-10/+7
Currently every dquot carries a wait_queue_head_t used only when we are turning quotas off to wait for last users to drop dquot references. Since such rare case is not performance sensitive in any means, just use a global waitqueue for this and save space in struct dquot. Also convert the logic to use wait_event() instead of open-coding it. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Move locking into clear_dquot_dirty()Jan Kara1-9/+6
Move locking of dq_list_lock into clear_dquot_dirty(). It makes the function more self-contained and will simplify our life later. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Do not dirty bad dquotsJan Kara1-8/+7
Currently we mark dirty even dquots that are not active (i.e., initialization or reading failed for them). Thus later we have to check whether dirty dquot is really active and just clear the dirty bit if not. Avoid this complication by just never marking non-active dquot as dirty. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Fix possible corruption of dqi_flagsJan Kara1-2/+7
dqi_flags modifications are protected by dq_data_lock. However the modifications in vfs_load_quota_inode() and in mark_info_dirty() were not which could lead to corruption of dqi_flags. Since modifications to dqi_flags are rare, this is hard to observe in practice but in theory it could happen. Fix the problem by always using dq_data_lock for protection. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Push dqio_sem down to ->read_file_info()Jan Kara1-5/+1
Push down acquisition of dqio_sem into ->read_file_info() callback. This is for consistency with other operations and it also allows us to get rid of an ugliness in OCFS2. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Push dqio_sem down to ->write_file_info()Jan Kara1-9/+1
Push down acquisition of dqio_sem into ->write_file_info() callback. Mostly for consistency with other operations. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Push dqio_sem down to ->get_next_id()Jan Kara1-5/+1
Push down acquisition of dqio_sem into ->get_next_id() callback. Mostly for consistency with other operations. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Push dqio_sem down to ->release_dqblk()Jan Kara1-2/+2
Push down acquisition of dqio_sem into ->release_dqblk() callback. It will allow quota formats to decide whether they need it or not. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Push dqio_sem down to ->write_dqblk()Jan Kara1-7/+4
Push down acquisition of dqio_sem into ->write_dqblk() callback. It will allow quota formats to decide whether they need it or not. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Push dqio_sem down to ->read_dqblk()Jan Kara1-4/+1
Push down acquisition of dqio_sem into ->read_dqblk() callback. It will allow quota formats to decide whether they need it or not. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Protect dquot writeout with dq_lockJan Kara1-14/+14
Currently dquot writeout is only protected by dqio_sem held for writing. As we transition to a finer grained locking we will use dquot->dq_lock instead. So acquire it in dquot_commit() and move dqio_sem just around ->commit_dqblk() call as it is still needed to serialize quota file changes. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Acquire dqio_sem for reading in vfs_load_quota_inode()Jan Kara1-3/+3
vfs_load_quota_inode() needs dqio_sem only for reading. In fact dqio_sem is not needed there at all since the function can be called only during quota on when quota file cannot be modified but let's leave the protection there since it is logical and the path is in no way performance critical. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Acquire dqio_sem for reading in dquot_get_next_id()Jan Kara1-2/+2
dquot_get_next_id() needs dqio_sem only for reading to protect against racing with modification of quota file structure. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Do more fine-grained locking in dquot_acquire()Jan Kara1-3/+6
We need dqio_sem held just for reading when calling ->read_dqblk() in dquot_acquire(). Also dqio_sem is not needed when setting DQ_READ_B and DQ_ACTIVE_B as concurrent reads and dquot activations are serialized by dq_lock. So acquire and release dqio_sem closer to the place where it is needed. This reduces lock hold time and will make locking changes easier. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-17quota: Convert dqio_mutex to rwsemJan Kara1-14/+14
Convert dqio_mutex to rwsem and call it dqio_sem. No functional changes yet. Signed-off-by: Jan Kara <jack@suse.cz>
2017-08-07quota: correct space limit checkzhangyi (F)1-6/+15
Currently we compare total space (curspace + rsvspace) with space limit in quota-tools when setting grace time and also in check_bdq(), but we missing rsvspace in somewhere else, correct them. This patch also fix incorrect zero dqb_btime and grace time updating failure when we use rsvspace(e.g. ext4 dalloc feature). Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz>
2017-06-22quota: add get_inode_usage callback to transfer multi-inode chargesTahsin Erdogan1-4/+12
Ext4 ea_inode feature allows storing xattr values in external inodes to be able to store values that are bigger than a block in size. Ext4 also has deduplication support for these type of inodes. With deduplication, the actual storage waste is eliminated but the users of such inodes are still charged full quota for the inodes as if there was no sharing happening in the background. This design requires ext4 to manually charge the users because the inodes are shared. An implication of this is that, if someone calls chown on a file that has such references we need to transfer the quota for the file and xattr inodes. Current dquot_transfer() function implicitly transfers one inode charge. With ea_inode feature, we would like to transfer multiple inode charges. Add get_inode_usage callback which can interrogate the total number of inodes that were charged for a given inode. [ Applied fix from Colin King to make sure the 'ret' variable is initialized on the successful return path. Detected by CoverityScan, CID#1446616 ("Uninitialized scalar variable") --tytso] Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Jan Kara <jack@suse.cz>
2017-05-24ext4: fix quota charging for shared xattr blocksTahsin Erdogan1-0/+16
ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr block when new references are made. However if dquot_initialize() hasn't been called on an inode, request for charging is effectively ignored because ext4_inode_info->i_dquot is not initialized yet. Add dquot_initialize() to call paths that lead to ext4_xattr_block_set(). Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-04-19quota: Remove dquot_quotactl_opsJan Kara1-12/+0
Nobody uses them anymore. Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-19quota: Stop setting IMMUTABLE and NOATIME flags on quota filesJan Kara1-14/+5
Currently we set IMMUTABLE and NOATIME flags on quota files to stop userspace from messing with them. Now that all filesystems set these flags in their quota_on handlers, we can stop setting the flags in generic quota code. This will allow filesystems to stop copying i_flags to their on-disk flags on various occasions. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz>
2017-03-02sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar1-0/+1
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-19Merge branch 'for_linus' of ↵Linus Torvalds1-89/+47
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota, fsnotify and ext2 updates from Jan Kara: "Changes to locking of some quota operations from dedicated quota mutex to s_umount semaphore, a fsnotify fix and a simple ext2 fix" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: quota: Fix bogus warning in dquot_disable() fsnotify: Fix possible use-after-free in inode iteration on umount ext2: reject inodes with negative size quota: Remove dqonoff_mutex ocfs2: Use s_umount for quota recovery protection quota: Remove dqonoff_mutex from dquot_scan_active() ocfs2: Protect periodic quota syncing with s_umount semaphore quota: Use s_umount protection for quota operations quota: Hold s_umount in exclusive mode when enabling / disabling quotas fs: Provide function to get superblock with exclusive s_umount
2016-12-19quota: Fix bogus warning in dquot_disable()Jan Kara1-2/+2
dquot_disable() was warning when sb_has_quota_loaded() was true when invalidating page cache for quota files. The thinking behind this warning was that we must have raced with somebody else turning quotas on and this should not happen because all places modifying quota state must hold s_umount exclusively now. However sb_has_quota_loaded() can be also true at this point when we are just suspending quotas on remount read-only. Just restore the behavior to situation before commit c3b004460d77 ("quota: Remove dqonoff_mutex") which introduced the warning. The code in dquot_disable() can be further simplified with the new locking of quota state changes however let's leave that to a separate commit that can get more testing exposure. Fixes: c3b004460d77bf3f980d877be539016f2df4df12 Signed-off-by: Jan Kara <jack@suse.cz>
2016-12-05quota: constify struct path in quota_onAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-11-30quota: Remove dqonoff_mutexJan Kara1-57/+23
The only places that were grabbing dqonoff_mutex are functions turning quotas on and off and these are properly serialized using s_umount semaphore. Remove dqonoff_mutex. Signed-off-by: Jan Kara <jack@suse.cz>
2016-11-30quota: Remove dqonoff_mutex from dquot_scan_active()Jan Kara1-2/+2
All callers of dquot_scan_active() now hold s_umount so we can rely on that lock to protect us against quota state changes. Signed-off-by: Jan Kara <jack@suse.cz>
2016-11-24quota: Use s_umount protection for quota operationsJan Kara1-29/+10
Writeback quota is protected by s_umount semaphore held for reading because every writeback must be protected by that lock (grabbed either by the generic writeback code or by quotactl handler). Getting next available ID in quota file, querying quota state, setting quota information, getting quota format are all quotactl operations protected by s_umount semaphore held for reading grabbed in quotactl handler. This also fixes lockdep splat about possible deadlock during filesystem freezing where sync_filesystem() is called with page-faults already blocked but sync_filesystem() calls into dquot_writeback_dquots() which grabs dqonoff_mutex which ranks above i_mutex (vfs_load_quota_inode() grabs i_mutex under dqonoff_mutex) which clearly ranks below page fault freeze protection (e.g. via mmap_sem dependencies). The reported problem is not a real deadlock possibility since during quota on we check whether filesystem freezing is not in progress but still it is good to have this fixed. Reported-by: Ted Tso <tytso@mit.edu> Reported-by: Eric Whitney <enwlinux@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2016-11-24quota: Hold s_umount in exclusive mode when enabling / disabling quotasJan Kara1-0/+11
Currently we hold s_umount semaphore only in shared mode when enabling or disabling quotas and use dqonoff_mutex for serializing quota state changes on a filesystem and also quota state changes with other places depending on current quota state. Using dedicated mutex for this causes possible deadlocks during filesystem freezing (see following commit for details) so we transition to using s_umount semaphore for the necessary synchronization whose lock ordering is properly handled by the filesystem freezing code. As a start grab s_umount in exclusive mode when enabling / disabling quotas. Signed-off-by: Jan Kara <jack@suse.cz>
2016-07-29Merge branch 'for-linus' of ↵Linus Torvalds1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns vfs updates from Eric Biederman: "This tree contains some very long awaited work on generalizing the user namespace support for mounting filesystems to include filesystems with a backing store. The real world target is fuse but the goal is to update the vfs to allow any filesystem to be supported. This patchset is based on a lot of code review and testing to approach that goal. While looking at what is needed to support the fuse filesystem it became clear that there were things like xattrs for security modules that needed special treatment. That the resolution of those concerns would not be fuse specific. That sorting out these general issues made most sense at the generic level, where the right people could be drawn into the conversation, and the issues could be solved for everyone. At a high level what this patchset does a couple of simple things: - Add a user namespace owner (s_user_ns) to struct super_block. - Teach the vfs to handle filesystem uids and gids not mapping into to kuids and kgids and being reported as INVALID_UID and INVALID_GID in vfs data structures. By assigning a user namespace owner filesystems that are mounted with only user namespace privilege can be detected. This allows security modules and the like to know which mounts may not be trusted. This also allows the set of uids and gids that are communicated to the filesystem to be capped at the set of kuids and kgids that are in the owning user namespace of the filesystem. One of the crazier corner casees this handles is the case of inodes whose i_uid or i_gid are not mapped into the vfs. Most of the code simply doesn't care but it is easy to confuse the inode writeback path so no operation that could cause an inode write-back is permitted for such inodes (aka only reads are allowed). This set of changes starts out by cleaning up the code paths involved in user namespace permirted mounts. Then when things are clean enough adds code that cleanly sets s_user_ns. Then additional restrictions are added that are possible now that the filesystem superblock contains owner information. These changes should not affect anyone in practice, but there are some parts of these restrictions that are changes in behavior. - Andy's restriction on suid executables that does not honor the suid bit when the path is from another mount namespace (think /proc/[pid]/fd/) or when the filesystem was mounted by a less privileged user. - The replacement of the user namespace implicit setting of MNT_NODEV with implicitly setting SB_I_NODEV on the filesystem superblock instead. Using SB_I_NODEV is a stronger form that happens to make this state user invisible. The user visibility can be managed but it caused problems when it was introduced from applications reasonably expecting mount flags to be what they were set to. There is a little bit of work remaining before it is safe to support mounting filesystems with backing store in user namespaces, beyond what is in this set of changes. - Verifying the mounter has permission to read/write the block device during mount. - Teaching the integrity modules IMA and EVM to handle filesystems mounted with only user namespace root and to reduce trust in their security xattrs accordingly. - Capturing the mounters credentials and using that for permission checks in d_automount and the like. (Given that overlayfs already does this, and we need the work in d_automount it make sense to generalize this case). Furthermore there are a few changes that are on the wishlist: - Get all filesystems supporting posix acls using the generic posix acls so that posix_acl_fix_xattr_from_user and posix_acl_fix_xattr_to_user may be removed. [Maintainability] - Reducing the permission checks in places such as remount to allow the superblock owner to perform them. - Allowing the superblock owner to chown files with unmapped uids and gids to something that is mapped so the files may be treated normally. I am not considering even obvious relaxations of permission checks until it is clear there are no more corner cases that need to be locked down and handled generically. Many thanks to Seth Forshee who kept this code alive, and putting up with me rewriting substantial portions of what he did to handle more corner cases, and for his diligent testing and reviewing of my changes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits) fs: Call d_automount with the filesystems creds fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns evm: Translate user/group ids relative to s_user_ns when computing HMAC dquot: For now explicitly don't support filesystems outside of init_user_ns quota: Handle quota data stored in s_user_ns in quota_setxquota quota: Ensure qids map to the filesystem vfs: Don't create inodes with a uid or gid unknown to the vfs vfs: Don't modify inodes with a uid or gid unknown to the vfs cred: Reject inodes with invalid ids in set_create_file_as() fs: Check for invalid i_uid in may_follow_link() vfs: Verify acls are valid within superblock's s_user_ns. userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS fs: Refuse uid/gid changes which don't map into s_user_ns selinux: Add support for unprivileged mounts from user namespaces Smack: Handle labels consistently in untrusted mounts Smack: Add support for unprivileged mounts from user namespaces fs: Treat foreign mounts as nosuid fs: Limit file caps to the user namespace of the super block userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag userns: Remove implicit MNT_NODEV fragility. ...
2016-07-05dquot: For now explicitly don't support filesystems outside of init_user_nsEric W. Biederman1-0/+5
Mostly supporting filesystems outside of init_user_ns is s/&init_usre_ns/dquot->dq_sb->s_user_ns/. An actual need for supporting quotas on filesystems outside of s_user_ns is quite a ways away and to be done responsibily needs an audit on what can happen with hostile quota files. Until that audit is complete don't attempt to support quota files on filesystems outside of s_user_ns. Cc: Jan Kara <jack@suse.cz> Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-07-05quota: Ensure qids map to the filesystemEric W. Biederman1-0/+3
Introduce the helper qid_has_mapping and use it to ensure that the quota system only considers qids that map to the filesystems s_user_ns. In practice for quota supporting filesystems today this is the exact same check as qid_valid. As only 0xffffffff aka (qid_t)-1 does not map into init_user_ns. Replace the qid_valid calls with qid_has_mapping as values come in from userspace. This is harmless today and it prepares the quota system to work on filesystems with quotas but mounted by unprivileged users. Call qid_has_mapping from dqget. This ensures the passed in qid has a prepresentation on the underlying filesystem. Previously this was unnecessary as filesystesm never had qids that could not map. With the introduction of filesystems outside of s_user_ns this will not remain true. All of this ensures the quota code never has to deal with qids that don't map to the underlying filesystem. Cc: Jan Kara <jack@suse.cz> Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-19quota: use time64_t internallyArnd Bergmann1-8/+8
The quota subsystem has two formats, the old v1 format using architecture specific time_t values on the on-disk format, while the v2 format (introduced in Linux 2.5.16 and 2.4.22) uses fixed 64-bit little-endian. While there is no future for the v1 format beyond y2038, the v2 format is almost there on 32-bit architectures, as both the user interface and the on-disk format use 64-bit timestamps, just not the time_t inbetween. This changes the internal representation to use time64_t, which will end up doing the right thing everywhere for v2 format. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jan Kara <jack@suse.cz>