kernel/git/stable/linux-stable.git/fs/kernfs, branch linux-5.0.y

kernfs: fix barrier usage in __kernfs_new_node()

2019-05-16T17:40:11+00:00

commit 998267900cee901c5d1dfa029a6304d00acbc29f upstream. smp_mb__before_atomic() can not be applied to atomic_set(). Remove the barrier and rely on RELEASE synchronization. Fixes: ba16b2846a8c6 ("kernfs: add an API to get kernfs node from inode number") Cc: stable@vger.kernel.org Signed-off-by: Andrea Parri Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

fix cgroup_do_mount() handling of failure exits

2019-03-23T19:11:15+00:00

commit 399504e21a10be16dd1408ba0147367d9d82a10c upstream. same story as with last May fixes in sysfs (7b745a4e4051 "unfuck sysfs_mount()"); new_sb is left uninitialized in case of early errors in kernfs_mount_ns() and papering over it by treating any error from kernfs_mount_ns() as equivalent to !new_ns ends up conflating the cases when objects had never been transferred to a superblock with ones when that has happened and resulting new superblock had been dropped. Easily fixed (same way as in sysfs case). Additionally, there's a superblock leak on kernfs_node_dentry() failure *and* a dentry leak inside kernfs_node_dentry() itself - the latter on probably impossible errors, but the former not impossible to trigger (as the matter of fact, injecting allocation failures at that point *does* trigger it). Cc: stable@kernel.org Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

kernfs: Improve kernfs_notify() poll notification latency

2018-11-27T10:59:33+00:00

kernfs_notify() does two notifications: poll and fsnotify. Originally, both notifications were done from scheduled work context and all that kernfs_notify() did was schedule the work. This patch simply moves the poll notification from the scheduled work handler to kernfs_notify(). The fsnotify notification still needs to be done from scheduled work context because it can sleep (it needs to lock a mutex). If the poll notification is time critical (the notified thread needs to wake as quickly as possible), it's better to do it from kernfs_notify() directly. One example is calling sysfs_notify_dirent() from a hardware interrupt handler to wake up a thread and handle the interrupt in user space. Signed-off-by: Radu Rendec Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

mm: zero-seek shrinkers

2018-10-26T23:26:33+00:00

The page cache and most shrinkable slab caches hold data that has been read from disk, but there are some caches that only cache CPU work, such as the dentry and inode caches of procfs and sysfs, as well as the subset of radix tree nodes that track non-resident page cache. Currently, all these are shrunk at the same rate: using DEFAULT_SEEKS for the shrinker's seeks setting tells the reclaim algorithm that for every two page cache pages scanned it should scan one slab object. This is a bogus setting. A virtual inode that required no IO to create is not twice as valuable as a page cache page; shadow cache entries with eviction distances beyond the size of memory aren't either. In most cases, the behavior in practice is still fine. Such virtual caches don't tend to grow and assert themselves aggressively, and usually get picked up before they cause problems. But there are scenarios where that's not true. Our database workloads suffer from two of those. For one, their file workingset is several times bigger than available memory, which has the kernel aggressively create shadow page cache entries for the non-resident parts of it. The workingset code does tell the VM that most of these are expendable, but the VM ends up balancing them 2:1 to cache pages as per the seeks setting. This is a huge waste of memory. These workloads also deal with tens of thousands of open files and use /proc for introspection, which ends up growing the proc_inode_cache to absurdly large sizes - again at the cost of valuable cache space, which isn't a reasonable trade-off, given that proc inodes can be re-created without involving the disk. This patch implements a "zero-seek" setting for shrinkers that results in a target ratio of 0:1 between their objects and IO-backed caches. This allows such virtual caches to grow when memory is available (they do cache/avoid CPU work after all), but effectively disables them as soon as IO-backed objects are under pressure. It then switches the shrinkers for procfs and sysfs metadata, as well as excess page cache shadow nodes, to the new zero-seek setting. Link: http://lkml.kernel.org/r/20181009184732.762-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Reported-by: Domas Mituzas Reviewed-by: Andrew Morton Reviewed-by: Rik van Riel Acked-by: Peter Zijlstra (Intel) Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernfs: Fix range checks in kernfs_get_target_path

2018-09-16T20:38:57+00:00

The terminating NUL byte is only there because the buffer is allocated with kzalloc(PAGE_SIZE, GFP_KERNEL), but since the range-check is off-by-one, and PAGE_SIZE==PATH_MAX, the returned string may not be zero-terminated if it is exactly PATH_MAX characters long. Furthermore also the initial loop may theoretically exceed PATH_MAX and cause a fault. Signed-off-by: Bernd Edlinger Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2018-08-18T18:44:53+00:00

Pull driver core updates from Greg KH: "Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported" * tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) base: core: Remove WARN_ON from link dependencies check drivers/base: stop new probing during shutdown drivers: core: Remove glue dirs from sysfs earlier driver core: remove unnecessary function extern declare sysfs.h: fix non-kernel-doc comment PM / Domains: Stop deferring probe at the end of initcall iommu: Remove IOMMU_OF_DECLARE iommu: Stop deferring probe at end of initcalls pinctrl: Support stopping deferred probe after initcalls dt-bindings: pinctrl: add a 'pinctrl-use-default' property driver core: allow stopping deferred probe after init driver core: add a debugfs entry to show deferred devices sysfs: Fix internal_create_group() for named group updates base: fix order of OF initialization linux/device.h: fix kernel-doc notation warning Documentation: update firmware loader fallback reference kobject: Replace strncpy with memcpy drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number kernfs: Replace strncpy with memcpy device: Add #define dev_fmt similar to #define pr_fmt ...

kernfs: allow creating kernfs objects with arbitrary uid/gid

2018-07-21T06:44:35+00:00

This change allows creating kernfs files and directories with arbitrary uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments. The "simple" kernfs_create_file() and kernfs_create_dir() are left alone and always create objects belonging to the global root. When creating symlinks ownership (uid/gid) is taken from the target kernfs object. Co-Developed-by: Tyler Hicks Signed-off-by: Dmitry Torokhov Signed-off-by: Tyler Hicks Signed-off-by: David S. Miller

kernfs: Replace strncpy with memcpy

2018-07-07T07:57:10+00:00

gcc 8.1.0 complains: fs/kernfs/symlink.c:91:3: warning: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length fs/kernfs/symlink.c: In function 'kernfs_iop_get_link': fs/kernfs/symlink.c:88:14: note: length computed here Using strncpy() is indeed less than perfect since the length of data to be copied has already been determined with strlen(). Replace strncpy() with memcpy() to address the warning and optimize the code a little. Signed-off-by: Guenter Roeck Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

Merge tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

2018-06-14T22:31:07+00:00

Pull inode timestamps conversion to timespec64 from Arnd Bergmann: "This is a late set of changes from Deepa Dinamani doing an automated treewide conversion of the inode and iattr structures from 'timespec' to 'timespec64', to push the conversion from the VFS layer into the individual file systems. As Deepa writes: 'The series aims to switch vfs timestamps to use struct timespec64. Currently vfs uses struct timespec, which is not y2038 safe. The series involves the following: 1. Add vfs helper functions for supporting struct timepec64 timestamps. 2. Cast prints of vfs timestamps to avoid warnings after the switch. 3. Simplify code using vfs timestamps so that the actual replacement becomes easy. 4. Convert vfs timestamps to use struct timespec64 using a script. This is a flag day patch. Next steps: 1. Convert APIs that can handle timespec64, instead of converting timestamps at the boundaries. 2. Update internal data structures to avoid timestamp conversions' Thomas Gleixner adds: 'I think there is no point to drag that out for the next merge window. The whole thing needs to be done in one go for the core changes which means that you're going to play that catchup game forever. Let's get over with it towards the end of the merge window'" * tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground: pstore: Remove bogus format string definition vfs: change inode times to use struct timespec64 pstore: Convert internal records to timespec64 udf: Simplify calls to udf_disk_stamp_to_time fs: nfs: get rid of memcpys for inode times ceph: make inode time prints to be long long lustre: Use long long type to print inode time fs: add timespec64_truncate()

Merge branch 'vfs_timespec64' of https://github.com/deepa-hub/vfs into vfs-timespec64

2018-06-14T12:54:00+00:00

Pull the timespec64 conversion from Deepa Dinamani: "The series aims to switch vfs timestamps to use struct timespec64. Currently vfs uses struct timespec, which is not y2038 safe. The flag patch applies cleanly. I've not seen the timestamps update logic change often. The series applies cleanly on 4.17-rc6 and linux-next tip (top commit: next-20180517). I'm not sure how to merge this kind of a series with a flag patch. We are targeting 4.18 for this. Let me know if you have other suggestions. The series involves the following: 1. Add vfs helper functions for supporting struct timepec64 timestamps. 2. Cast prints of vfs timestamps to avoid warnings after the switch. 3. Simplify code using vfs timestamps so that the actual replacement becomes easy. 4. Convert vfs timestamps to use struct timespec64 using a script. This is a flag day patch. I've tried to keep the conversions with the script simple, to aid in the reviews. I've kept all the internal filesystem data structures and function signatures the same. Next steps: 1. Convert APIs that can handle timespec64, instead of converting timestamps at the boundaries. 2. Update internal data structures to avoid timestamp conversions." I've pulled it into a branch based on top of the NFS changes that are now in mainline, so I could resolve the non-obvious conflict between the two while merging. Signed-off-by: Arnd Bergmann