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2017-11-17Merge branch 'overlayfs-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: - Report constant st_ino values across copy-up even if underlying layers are on different filesystems, but using different st_dev values for each layer. Ideally we'd report the same st_dev across the overlay, and it's possible to do for filesystems that use only 32bits for st_ino by unifying the inum space. It would be nice if it wasn't a choice of 32 or 64, rather filesystems could report their current maximum (that could change on resize, so it wouldn't be set in stone). - miscellaneus fixes and a cleanup of ovl_fill_super(), that was long overdue. - created a path_put_init() helper that clears out the pointers after putting the ref. I think this could be useful elsewhere, so added it to <linux/path.h> * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (30 commits) ovl: remove unneeded arg from ovl_verify_origin() ovl: Put upperdentry if ovl_check_origin() fails ovl: rename ufs to ofs ovl: clean up getting lower layers ovl: clean up workdir creation ovl: clean up getting upper layer ovl: move ovl_get_workdir() and ovl_get_lower_layers() ovl: reduce the number of arguments for ovl_workdir_create() ovl: change order of setup in ovl_fill_super() ovl: factor out ovl_free_fs() helper ovl: grab reference to workbasedir early ovl: split out ovl_get_indexdir() from ovl_fill_super() ovl: split out ovl_get_lower_layers() from ovl_fill_super() ovl: split out ovl_get_workdir() from ovl_fill_super() ovl: split out ovl_get_upper() from ovl_fill_super() ovl: split out ovl_get_lowerstack() from ovl_fill_super() ovl: split out ovl_get_workpath() from ovl_fill_super() ovl: split out ovl_get_upperpath() from ovl_fill_super() ovl: use path_put_init() in error paths for ovl_fill_super() vfs: add path_put_init() ...
2017-11-10ovl: remove unneeded arg from ovl_verify_origin()Amir Goldstein
Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: Put upperdentry if ovl_check_origin() failsVivek Goyal
If ovl_check_origin() fails, we should put upperdentry. We have a reference on it by now. So goto out_put_upper instead of out. Fixes: a9d019573e88 ("ovl: lookup non-dir copy-up-origin by file handle") Cc: <stable@vger.kernel.org> #4.12 Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: rename ufs to ofsMiklos Szeredi
Rename all "struct ovl_fs" pointers to "ofs". The "ufs" name is historical and can only be found in overlayfs/super.c. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: clean up getting lower layersMiklos Szeredi
Move calling ovl_get_lower_layers() into ovl_get_lowerstack(). ovl_get_lowerstack() now returns the root dentry's filled in ovl_entry. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: clean up workdir creationMiklos Szeredi
Move calling ovl_get_workdir() into ovl_get_workpath(). Rename ovl_get_workdir() to ovl_make_workdir() and ovl_get_workpath() to ovl_get_workdir(). Workpath is now not needed outside ovl_get_workdir(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: clean up getting upper layerMiklos Szeredi
Merge ovl_get_upper() and ovl_get_upperpath(). The resulting function is named ovl_get_upper(), though it still returns upperpath as well. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: move ovl_get_workdir() and ovl_get_lower_layers()Miklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: reduce the number of arguments for ovl_workdir_create()Miklos Szeredi
Remove "sb" and "dentry" arguments of ovl_workdir_create() and related functions. Move setting MS_RDONLY flag to callers. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: change order of setup in ovl_fill_super()Miklos Szeredi
Move ovl_get_upper() immediately after ovl_get_upperpath(), ovl_get_workdir() immediately after ovl_get_workdir() and ovl_get_lower_layers() immediately after ovl_get_lowerstack(). Also move prepare_creds() up to where other allocations are happening. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-10ovl: factor out ovl_free_fs() helperMiklos Szeredi
This can be called both from ovl_put_super() and in the error cleanup path from ovl_fill_super(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: grab reference to workbasedir earlyMiklos Szeredi
and related cleanups. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_indexdir() from ovl_fill_super()Miklos Szeredi
It's okay to get rid of the intermediate error label due to ufs being zeroed on allocation. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_lower_layers() from ovl_fill_super()Miklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_workdir() from ovl_fill_super()Miklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_upper() from ovl_fill_super()Miklos Szeredi
And don't clobber ufs->upper_mnt on error. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_lowerstack() from ovl_fill_super()Miklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_workpath() from ovl_fill_super()Miklos Szeredi
It's okay to get rid of the intermediate error label due to ufs being zeroed on allocation. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: split out ovl_get_upperpath() from ovl_fill_super()Miklos Szeredi
It's okay to get rid of the intermediate error label due to ufs being zeroed on allocation. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: use path_put_init() in error paths for ovl_fill_super()Miklos Szeredi
This allows simplifying the error cleanup later. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: update cache version of impure parent on renameAmir Goldstein
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: relax same fs constraint for constant st_inoAmir Goldstein
For the case of all layers not on the same fs, return the copy up origin inode st_dev/st_ino for non-dir from stat(2). This guaranties constant st_dev/st_ino for non-dir across copy up. Like the same fs case, st_ino of non-dir is also persistent. If the st_dev/st_ino for copied up object would have been the same as that of the real underlying lower file, running diff on underlying lower file and overlay copied up file would result in diff reporting that the two files are equal when in fact, they may have different content. Therefore, unlike the same fs case, st_dev is not persistent because it uses the unique anonymous bdev allocated for the lower layer. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: return anonymous st_dev for lower inodesChandan Rajendra
For non-samefs setup, to make sure that st_dev/st_ino pair is unique across the system, we return a unique anonymous st_dev for stat(2) of lower layer inode. A following patch is going to fix constant st_dev/st_ino across copy up by returning origin st_dev/st_ino for copied up objects. If the st_dev/st_ino for copied up object would have been the same as that of the real underlying lower file, running diff on underlying lower file and overlay copied up file would result in diff reporting that the 2 files are equal when in fact, they may have different content. [amir: simplify ovl_get_pseudo_dev() split from allocate anonymous bdev patch] Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: allocate anonymous devs for lowerdirsChandan Rajendra
Generate unique values of st_dev per lower layer for non-samefs overlay mount. The unique values are obtained by allocating anonymous bdevs for each of the lowerdirs in the overlayfs instance. The anonymous bdev is going to be returned by stat(2) for lowerdir non-dir entries in non-samefs case. [amir: split from ovl_getattr() and re-structure patches] Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: re-structure overlay lower layers in-memoryChandan Rajendra
Define new structures to represent overlay instance lower layers and overlay merge dir lower layers to make room for storing more per layer information in-memory. Instead of keeping the fs instance lower layers in an array of struct vfsmount, keep them in an array of new struct ovl_layer, that has a pointer to struct vfsmount. Instead of keeping the dentry lower layers in an array of struct path, keep them in an array of new struct ovl_path, that has a pointer to struct dentry and to struct ovl_layer. Add a small helper to find the fs layer id that correspopnds to a lower struct ovl_path and use it in ovl_lookup(). [amir: split re-structure from anonymous bdev patch] Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: move include of ovl_entry.h into overlayfs.hAmir Goldstein
Most overlayfs c files already explicitly include ovl_entry.h to use overlay entry struct definitions and upcoming changes are going to require even more c files to include this header. All overlayfs c files include overlayfs.h and overlayfs.h itself refers to some structs defined in ovl_entry.h, so it seems more logic to include ovl_entry.h from overlayfs.h than from c files. 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)
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)
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>
2017-11-09ovl: no direct iteration for dir with origin xattrAmir Goldstein
If a non-merge dir in an overlay mount has an overlay.origin xattr, it means it was once an upper merge dir, which may contain whiteouts and then the lower dir was removed under it. Do not iterate real dir directly in this case to avoid exposing whiteouts. [SzM] Set OVL_WHITEOUT for all merge directories as well. [amir] A directory that was just copied up does not have the OVL_WHITEOUTS flag. We need to set it to fix merge dir iteration. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-09ovl: lockdep annotate of nested OVL_I(inode)->lockAmir Goldstein
This fixes a lockdep splat when mounting a nested overlayfs. Fixes: a015dafcaf5b ("ovl: use ovl_inode mutex to synchronize...") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-24ovl: do not cleanup unsupported index entriesAmir Goldstein
With index=on, ovl_indexdir_cleanup() tries to cleanup invalid index entries (e.g. bad index name). This behavior could result in cleaning of entries created by newer kernels and is therefore undesirable. Instead, abort mount if such entries are encountered. We still cleanup 'stale' entries and 'orphan' entries, both those cases can be a result of offline changes to lower and upper dirs. When encoutering an index entry of type directory or whiteout, kernel was supposed to fallback to read-only mount, but the fill_super() operation returns EROFS in this case instead of returning success with read-only mount flag, so mount fails when encoutering directory or whiteout index entries. Bless this behavior by returning -EINVAL on directory and whiteout index entries as we do for all unsupported index entries. Fixes: 61b674710cd9 ("ovl: do not cleanup directory and whiteout index..") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2017-10-24ovl: handle ENOENT on index lookupAmir Goldstein
Treat ENOENT from index entry lookup the same way as treating a returned negative dentry. Apparently, either could be returned if file is not found, depending on the underlying file system. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2017-10-24ovl: fix EIO from lookup of non-indexed upperAmir Goldstein
Commit fbaf94ee3cd5 ("ovl: don't set origin on broken lower hardlink") attempt to avoid the condition of non-indexed upper inode with lower hardlink as origin. If this condition is found, lookup returns EIO. The protection of commit mentioned above does not cover the case of lower that is not a hardlink when it is copied up (with either index=off/on) and then lower is hardlinked while overlay is offline. Changes to lower layer while overlayfs is offline should not result in unexpected behavior, so a permanent EIO error after creating a link in lower layer should not be considered as correct behavior. This fix replaces EIO error with success in cases where upper has origin but no index is found, or index is found that does not match upper inode. In those cases, lookup will not fail and the returned overlay inode will be hashed by upper inode instead of by lower origin inode. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-24locking/barriers: Convert users of lockless_dereference() to READ_ONCE()Will Deacon
READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-19ovl: Return -ENOMEM if an allocation fails ovl_lookup()Dan Carpenter
The error code is missing here so it means we return ERR_PTR(0) or NULL. The other error paths all return an error code so this probably should as well. Fixes: 02b69b284cd7 ("ovl: lookup redirects") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-19ovl: add NULL check in ovl_alloc_inodeHirofumi Nakagawa
This was detected by fault injection test Signed-off-by: Hirofumi Nakagawa <nklabs@gmail.com> Fixes: 13cf199d0088 ("ovl: allocate an ovl_inode struct") Cc: <stable@vger.kernel.org> # v4.13
2017-10-05ovl: fix regression caused by exclusive upper/work dir protectionAmir Goldstein
Enforcing exclusive ownership on upper/work dirs caused a docker regression: https://github.com/moby/moby/issues/34672. Euan spotted the regression and pointed to the offending commit. Vivek has brought the regression to my attention and provided this reproducer: Terminal 1: mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none merged/ Terminal 2: unshare -m Terminal 1: umount merged mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none merged/ mount: /root/overlay-testing/merged: none already mounted or mount point busy To fix the regression, I replaced the error with an alarming warning. With index feature enabled, mount does fail, but logs a suggestion to override exclusive dir protection by disabling index. Note that index=off mount does take the inuse locks, so a concurrent index=off will issue the warning and a concurrent index=on mount will fail. Documentation was updated to reflect this change. Fixes: 2cac0c00a6cd ("ovl: get exclusive ownership on upper/work dirs") Cc: <stable@vger.kernel.org> # v4.13 Reported-by: Euan Kemp <euank@euank.com> Reported-by: Vivek Goyal <vgoyal@redhat.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 Goldstein
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>
2017-10-05ovl: fix dentry leak in ovl_indexdir_cleanup()Amir Goldstein
index dentry was not released when breaking out of the loop due to index verification error. Fixes: 415543d5c64f ("ovl: cleanup bad and stale index entries on mount") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-05ovl: fix dput() of ERR_PTR in ovl_cleanup_index()Amir Goldstein
Fixes: caf70cb2ba5d ("ovl: cleanup orphan index entries") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-05ovl: fix error value printed in ovl_lookup_index()Amir Goldstein
Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-14Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount flag updates from Al Viro: "Another chunk of fmount preparations from dhowells; only trivial conflicts for that part. It separates MS_... bits (very grotty mount(2) ABI) from the struct super_block ->s_flags (kernel-internal, only a small subset of MS_... stuff). This does *not* convert the filesystems to new constants; only the infrastructure is done here. The next step in that series is where the conflicts would be; that's the conversion of filesystems. It's purely mechanical and it's better done after the merge, so if you could run something like list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$') sed -i -e 's/\<MS_RDONLY\>/SB_RDONLY/g' \ -e 's/\<MS_NOSUID\>/SB_NOSUID/g' \ -e 's/\<MS_NODEV\>/SB_NODEV/g' \ -e 's/\<MS_NOEXEC\>/SB_NOEXEC/g' \ -e 's/\<MS_SYNCHRONOUS\>/SB_SYNCHRONOUS/g' \ -e 's/\<MS_MANDLOCK\>/SB_MANDLOCK/g' \ -e 's/\<MS_DIRSYNC\>/SB_DIRSYNC/g' \ -e 's/\<MS_NOATIME\>/SB_NOATIME/g' \ -e 's/\<MS_NODIRATIME\>/SB_NODIRATIME/g' \ -e 's/\<MS_SILENT\>/SB_SILENT/g' \ -e 's/\<MS_POSIXACL\>/SB_POSIXACL/g' \ -e 's/\<MS_KERNMOUNT\>/SB_KERNMOUNT/g' \ -e 's/\<MS_I_VERSION\>/SB_I_VERSION/g' \ -e 's/\<MS_LAZYTIME\>/SB_LAZYTIME/g' \ $list and commit it with something along the lines of 'convert filesystems away from use of MS_... constants' as commit message, it would save a quite a bit of headache next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: Differentiate mount flags (MS_*) from internal superblock flags VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags
2017-09-13mm: treewide: remove GFP_TEMPORARY allocation flagMichal Hocko
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>
2017-09-13Merge branch 'overlayfs-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "This fixes d_ino correctness in readdir, which brings overlayfs on par with normal filesystems regarding inode number semantics, as long as all layers are on the same filesystem. There are also some bug fixes, one in particular (random ioctl's shouldn't be able to modify lower layers) that touches some vfs code, but of course no-op for non-overlay fs" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix false positive ESTALE on lookup ovl: don't allow writing ioctl on lower layer ovl: fix relatime for directories vfs: add flags to d_real() ovl: cleanup d_real for negative ovl: constant d_ino for non-merge dirs ovl: constant d_ino across copy up ovl: fix readdir error value ovl: check snprintf return
2017-09-12ovl: fix false positive ESTALE on lookupAmir Goldstein
Commit b9ac5c274b8c ("ovl: hash overlay non-dir inodes by copy up origin") verifies that the origin lower inode stored in the overlayfs inode matched the inode of a copy up origin dentry found by lookup. There is a false positive result in that check when lower fs does not support file handles and copy up origin cannot be followed by file handle at lookup time. The false negative happens when finding an overlay inode in cache on a copied up overlay dentry lookup. The overlay inode still 'remembers' the copy up origin inode, but the copy up origin dentry is not available for verification. Relax the check in case copy up origin dentry is not available. Fixes: b9ac5c274b8c ("ovl: hash overlay non-dir inodes by copy up...") Cc: <stable@vger.kernel.org> # v4.13 Reported-by: Jordi Pujol <jordipujolp@gmail.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-05ovl: fix relatime for directoriesMiklos Szeredi
Need to treat non-regular overlayfs files the same as regular files when checking for an atime update. Add a d_real() flag to make it return the upper dentry for all file types. Reported-by: "zhangyi (F)" <yi.zhang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-04vfs: add flags to d_real()Miklos Szeredi
Add a separate flags argument (in addition to the open flags) to control the behavior of d_real(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-04ovl: cleanup d_real for negativeMiklos Szeredi
d_real() is never called with a negative dentry. So remove the d_is_negative() check (which would never trigger anyway, since d_is_reg() returns false for a negative dentry). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-08-10overlayfs, locking: Remove smp_mb__before_spinlock() usagePeter Zijlstra
While we could replace the smp_mb__before_spinlock() with the new smp_mb__after_spinlock(), the normal pattern is to use smp_store_release() to publish an object that is used for lockless_dereference() -- and mirrors the regular rcu_assign_pointer() / rcu_dereference() patterns. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>