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* tmpfs: fix SEEK_DATA/SEEK_HOLE regressionHugh Dickins2013-08-041-1/+2
| | | | | | | | | | | | Commit 46a1c2c7ae53 ("vfs: export lseek_execute() to modules") broke the tmpfs SEEK_DATA/SEEK_HOLE implementation, because vfs_setpos() converts the carefully prepared -ENXIO to -EINVAL. Other filesystems avoid it in error cases: do the same in tmpfs. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-07-031-8/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "In this update, Smack learns to love IPv6 and to mount a filesystem with a transmutable hierarchy (i.e. security labels are inherited from parent directory upon creation rather than creating process). The rest of the changes are maintenance" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (37 commits) tpm/tpm_i2c_infineon: Remove unused header file tpm: tpm_i2c_infinion: Don't modify i2c_client->driver evm: audit integrity metadata failures integrity: move integrity_audit_msg() evm: calculate HMAC after initializing posix acl on tmpfs maintainers: add Dmitry Kasatkin Smack: Fix the bug smackcipso can't set CIPSO correctly Smack: Fix possible NULL pointer dereference at smk_netlbl_mls() Smack: Add smkfstransmute mount option Smack: Improve access check performance Smack: Local IPv6 port based controls tpm: fix regression caused by section type conflict of tpm_dev_release() in ppc builds maintainers: Remove Kent from maintainers tpm: move TPM_DIGEST_SIZE defintion tpm_tis: missing platform_driver_unregister() on error in init_tis() security: clarify cap_inode_getsecctx description apparmor: no need to delay vfree() apparmor: fix fully qualified name parsing apparmor: fix setprocattr arg processing for onexec apparmor: localize getting the security context to a few macros ...
| * evm: calculate HMAC after initializing posix acl on tmpfsMimi Zohar2013-06-201-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | Included in the EVM hmac calculation is the i_mode. Any changes to the i_mode need to be reflected in the hmac. shmem_mknod() currently calls generic_acl_init(), which modifies the i_mode, after calling security_inode_init_security(). This patch reverses the order in which they are called. Reported-by: Sven Vermeulen <sven.vermeulen@siphos.be> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Hugh Dickins <hughd@google.com>
* | vfs: export lseek_execute() to modulesJie Liu2013-07-031-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For those file systems(btrfs/ext4/ocfs2/tmpfs) that support SEEK_DATA/SEEK_HOLE functions, we end up handling the similar matter in lseek_execute() to update the current file offset to the desired offset if it is valid, ceph also does the simliar things at ceph_llseek(). To reduce the duplications, this patch make lseek_execute() public accessible so that we can call it directly from the underlying file systems. Thanks Dave Chinner for this suggestion. [AV: call it vfs_setpos(), don't bring the removed 'inode' argument back] v2->v1: - Add kernel-doc comments for lseek_execute() - Call lseek_execute() in ceph->llseek() Signed-off-by: Jie Liu <jeff.liu@oracle.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Mason <chris.mason@fusionio.com> Cc: Josef Bacik <jbacik@fusionio.com> Cc: Ben Myers <bpm@sgi.com> Cc: Ted Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Sage Weil <sage@inktank.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | [O_TMPFILE] it's still short a few helpers, but infrastructure should be OK ↵Al Viro2013-06-291-0/+32
|/ | | | | | now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* aio: don't include aio.h in sched.hKent Overstreet2013-05-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/shmem.c: remove an ifdefAndrew Morton2013-04-291-4/+1
| | | | | | | | | | | Create a CONFIG_MMU=y stub for ramfs_nommu_expand_for_mapping() in the usual fashion. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Wolfram Sang <wsa@the-dreams.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix nommu breakage in shmem.cAl Viro2013-03-011-3/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-02-261-21/+31
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...
| * fs: encode_fh: return FILEID_INVALID if invalid fid_typeNamjae Jeon2013-02-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a follow up on below patch: [PATCH] exportfs: add FILEID_INVALID to indicate invalid fid_type commit: 216b6cbdcbd86b1db0754d58886b466ae31f5a63 Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Vivek Trivedi <t.vivek@samsung.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Sage Weil <sage@inktank.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * shmem_setup_file(): use d_alloc_pseudo() instead of d_alloc()Al Viro2013-02-261-4/+15
| | | | | | | | | | | | | | | | | | Note that provided ->d_dname() reproduces what we used to get for those guys in e.g. /proc/self/maps; it might be a good idea to change that to something less ugly, but for now let's keep the existing user-visible behaviour Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * clean shmem_file_setup() a bitAl Viro2013-02-221-10/+9
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fs: Preserve error code in get_empty_filp(), part 2Anatol Pomozov2013-02-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allocating a file structure in function get_empty_filp() might fail because of several reasons: - not enough memory for file structures - operation is not allowed - user is over its limit Currently the function returns NULL in all cases and we loose the exact reason of the error. All callers of get_empty_filp() assume that the function can fail with ENFILE only. Return error through pointer. Change all callers to preserve this error code. [AV: cleaned up a bit, carved the get_empty_filp() part out into a separate commit (things remaining here deal with alloc_file()), removed pipe(2) behaviour change] Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helper: file_inode(file)Al Viro2013-02-221-6/+6
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2013-02-251-0/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace and namespace infrastructure changes from Eric W Biederman: "This set of changes starts with a few small enhnacements to the user namespace. reboot support, allowing more arbitrary mappings, and support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the user namespace root. I do my best to document that if you care about limiting your unprivileged users that when you have the user namespace support enabled you will need to enable memory control groups. There is a minor bug fix to prevent overflowing the stack if someone creates way too many user namespaces. The bulk of the changes are a continuation of the kuid/kgid push down work through the filesystems. These changes make using uids and gids typesafe which ensures that these filesystems are safe to use when multiple user namespaces are in use. The filesystems converted for 3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs. The changes for these filesystems were a little more involved so I split the changes into smaller hopefully obviously correct changes. XFS is the only filesystem that remains. I was hoping I could get that in this release so that user namespace support would be enabled with an allyesconfig or an allmodconfig but it looks like the xfs changes need another couple of days before it they are ready." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits) cifs: Enable building with user namespaces enabled. cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t cifs: Convert struct cifs_sb_info to use kuids and kgids cifs: Modify struct smb_vol to use kuids and kgids cifs: Convert struct cifsFileInfo to use a kuid cifs: Convert struct cifs_fattr to use kuid and kgids cifs: Convert struct tcon_link to use a kuid. cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t cifs: Convert from a kuid before printing current_fsuid cifs: Use kuids and kgids SID to uid/gid mapping cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc cifs: Use BUILD_BUG_ON to validate uids and gids are the same size cifs: Override unmappable incoming uids and gids nfsd: Enable building with user namespaces enabled. nfsd: Properly compare and initialize kuids and kgids nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids nfsd: Modify nfsd4_cb_sec to use kuids and kgids nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion nfsd: Convert nfsxdr to use kuids and kgids nfsd: Convert nfs3xdr to use kuids and kgids ...
| * | userns: Allow the userns root to mount tmpfs.Eric W. Biederman2013-01-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no backing store to tmpfs and file creation rules are the same as for any other filesystem so it is semantically safe to allow unprivileged users to mount it. ramfs is safe for the same reasons so allow either flavor of tmpfs to be mounted by a user namespace root user. The memory control group successfully limits how much memory tmpfs can consume on any system that cares about a user namespace root using tmpfs to exhaust memory the memory control group can be deployed. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | tmpfs: fix mempolicy object leaksGreg Thelen2013-02-231-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix several mempolicy leaks in the tmpfs mount logic. These leaks are slow - on the order of one object leaked per mount attempt. Leak 1 (umount doesn't free mpol allocated in mount): while true; do mount -t tmpfs -o mpol=interleave,size=100M nodev /mnt umount /mnt done Leak 2 (errors parsing remount options will leak mpol): mount -t tmpfs -o size=100M nodev /mnt while true; do mount -o remount,mpol=interleave,size=x /mnt 2> /dev/null done umount /mnt Leak 3 (multiple mpol per mount leak mpol): while true; do mount -t tmpfs -o mpol=interleave,mpol=interleave,size=100M nodev /mnt umount /mnt done This patch fixes all of the above. I could have broken the patch into three pieces but is seemed easier to review as one. [akpm@linux-foundation.org: fix handling of mpol_parse_str() errors, per Hugh] Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | tmpfs: fix use-after-free of mempolicy objectGreg Thelen2013-02-231-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tmpfs remount logic preserves filesystem mempolicy if the mpol=M option is not specified in the remount request. A new policy can be specified if mpol=M is given. Before this patch remounting an mpol bound tmpfs without specifying mpol= mount option in the remount request would set the filesystem's mempolicy object to a freed mempolicy object. To reproduce the problem boot a DEBUG_PAGEALLOC kernel and run: # mkdir /tmp/x # mount -t tmpfs -o size=100M,mpol=interleave nodev /tmp/x # grep /tmp/x /proc/mounts nodev /tmp/x tmpfs rw,relatime,size=102400k,mpol=interleave:0-3 0 0 # mount -o remount,size=200M nodev /tmp/x # grep /tmp/x /proc/mounts nodev /tmp/x tmpfs rw,relatime,size=204800k,mpol=??? 0 0 # note ? garbage in mpol=... output above # dd if=/dev/zero of=/tmp/x/f count=1 # panic here Panic: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) [...] Oops: 0010 [#1] SMP DEBUG_PAGEALLOC Call Trace: mpol_shared_policy_init+0xa5/0x160 shmem_get_inode+0x209/0x270 shmem_mknod+0x3e/0xf0 shmem_create+0x18/0x20 vfs_create+0xb5/0x130 do_last+0x9a1/0xea0 path_openat+0xb3/0x4d0 do_filp_open+0x42/0xa0 do_sys_open+0xfe/0x1e0 compat_sys_open+0x1b/0x20 cstar_dispatch+0x7/0x1f Non-debug kernels will not crash immediately because referencing the dangling mpol will not cause a fault. Instead the filesystem will reference a freed mempolicy object, which will cause unpredictable behavior. The problem boils down to a dropped mpol reference below if shmem_parse_options() does not allocate a new mpol: config = *sbinfo shmem_parse_options(data, &config, true) mpol_put(sbinfo->mpol) sbinfo->mpol = config.mpol /* BUG: saves unreferenced mpol */ This patch avoids the crash by not releasing the mempolicy if shmem_parse_options() doesn't create a new mpol. How far back does this issue go? I see it in both 2.6.36 and 3.3. I did not look back further. Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: shmem: use new radix tree iteratorJohannes Weiner2013-02-231-13/+12
| |/ |/| | | | | | | | | | | | | | | | | | | | | In shmem_find_get_pages_and_swap(), use the faster radix tree iterator construct from commit 78c1d78488a3 ("radix-tree: introduce bit-optimized iterator"). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mempolicy: remove arg from mpol_parse_str, mpol_to_strHugh Dickins2013-01-021-2/+2
|/ | | | | | | | Remove the unused argument (formerly no_context) from mpol_parse_str() and from mpol_to_str(). Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lseek: the "whence" argument is called "whence"Andrew Morton2012-12-171-10/+10
| | | | | | | | | But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: support SEEK_DATA and SEEK_HOLE (reprise)Hugh Dickins2012-12-121-1/+91
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert 3.5's commit f21f8062201f ("tmpfs: revert SEEK_DATA and SEEK_HOLE") to reinstate 4fb5ef089b28 ("tmpfs: support SEEK_DATA and SEEK_HOLE"), with the intervening additional arg to generic_file_llseek_size(). In 3.8, ext4 is expected to join btrfs, ocfs2 and xfs with proper SEEK_DATA and SEEK_HOLE support; and a good case has now been made for it on tmpfs, so let's join the party. It's quite easy for tmpfs to scan the radix_tree to support llseek's new SEEK_DATA and SEEK_HOLE options: so add them while the minutiae are still on my mind (in particular, the !PageUptodate-ness of pages fallocated but still unwritten). [akpm@linux-foundation.org: fix warning with CONFIG_TMPFS=n] Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jaegeuk Hanse <jaegeuk.hanse@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Zheng Liu <wenqing.lz@taobao.com> Cc: Jeff liu <jeff.liu@oracle.com> Cc: Paul Eggert <eggert@cs.ucla.edu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Josef Bacik <josef@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andreas Dilger <adilger@dilger.ca> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Chris Mason <chris.mason@fusionio.com> Cc: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: fix shared mempolicy leakMel Gorman2012-12-061-10/+16
| | | | | | | | | | | | | | | | | | | | | | | This fixes a regression in 3.7-rc, which has since gone into stable. Commit 00442ad04a5e ("mempolicy: fix a memory corruption by refcount imbalance in alloc_pages_vma()") changed get_vma_policy() to raise the refcount on a shmem shared mempolicy; whereas shmem_alloc_page() went on expecting alloc_page_vma() to drop the refcount it had acquired. This deserves a rework: but for now fix the leak in shmem_alloc_page(). Hugh: shmem_swapin() did not need a fix, but surely it's clearer to use the same refcounting there as in shmem_alloc_page(), delete its onstack mempolicy, and the strange mpol_cond_copy() and __mpol_cond_copy() - those were invented to let swapin_readahead() make an unknown number of calls to alloc_pages_vma() with one mempolicy; but since 00442ad04a5e, alloc_pages_vma() has kept refcount in balance, so now no problem. Reported-and-tested-by: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: change final i_blocks BUG to WARNINGHugh Dickins2012-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Under a particular load on one machine, I have hit shmem_evict_inode()'s BUG_ON(inode->i_blocks), enough times to narrow it down to a particular race between swapout and eviction. It comes from the "if (freed > 0)" asymmetry in shmem_recalc_inode(), and the lack of coherent locking between mapping's nrpages and shmem's swapped count. There's a window in shmem_writepage(), between lowering nrpages in shmem_delete_from_page_cache() and then raising swapped count, when the freed count appears to be +1 when it should be 0, and then the asymmetry stops it from being corrected with -1 before hitting the BUG. One answer is coherent locking: using tree_lock throughout, without info->lock; reasonable, but the raw_spin_lock in percpu_counter_add() on used_blocks makes that messier than expected. Another answer may be a further effort to eliminate the weird shmem_recalc_inode() altogether, but previous attempts at that failed. So far undecided, but for now change the BUG_ON to WARN_ON: in usual circumstances it remains a useful consistency check. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: fix shmem_getpage_gfp() VM_BUG_ONHugh Dickins2012-11-161-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fuzzing with trinity hit the "impossible" VM_BUG_ON(error) (which Fedora has converted to WARNING) in shmem_getpage_gfp(): WARNING: at mm/shmem.c:1151 shmem_getpage_gfp+0xa5c/0xa70() Pid: 29795, comm: trinity-child4 Not tainted 3.7.0-rc2+ #49 Call Trace: warn_slowpath_common+0x7f/0xc0 warn_slowpath_null+0x1a/0x20 shmem_getpage_gfp+0xa5c/0xa70 shmem_fault+0x4f/0xa0 __do_fault+0x71/0x5c0 handle_pte_fault+0x97/0xae0 handle_mm_fault+0x289/0x350 __do_page_fault+0x18e/0x530 do_page_fault+0x2b/0x50 page_fault+0x28/0x30 tracesys+0xe1/0xe6 Thanks to Johannes for pointing to truncation: free_swap_and_cache() only does a trylock on the page, so the page lock we've held since before confirming swap is not enough to protect against truncation. What cleanup is needed in this case? Just delete_from_swap_cache(), which takes care of the memcg uncharge. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Dave Jones <davej@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checkingHugh Dickins2012-10-091-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fuzzing with trinity oopsed on the 1st instruction of shmem_fh_to_dentry(), u64 inum = fid->raw[2]; which is unhelpfully reported as at the end of shmem_alloc_inode(): BUG: unable to handle kernel paging request at ffff880061cd3000 IP: [<ffffffff812190d0>] shmem_alloc_inode+0x40/0x40 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Call Trace: [<ffffffff81488649>] ? exportfs_decode_fh+0x79/0x2d0 [<ffffffff812d77c3>] do_handle_open+0x163/0x2c0 [<ffffffff812d792c>] sys_open_by_handle_at+0xc/0x10 [<ffffffff83a5f3f8>] tracesys+0xe1/0xe6 Right, tmpfs is being stupid to access fid->raw[2] before validating that fh_len includes it: the buffer kmalloc'ed by do_sys_name_to_handle() may fall at the end of a page, and the next page not be present. But some other filesystems (ceph, gfs2, isofs, reiserfs, xfs) are being careless about fh_len too, in fh_to_dentry() and/or fh_to_parent(), and could oops in the same way: add the missing fh_len checks to those. Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Sage Weil <sage@inktank.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mm: kill vma flag VM_CAN_NONLINEARKonstantin Khlebnikov2012-10-091-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move actual pte filling for non-linear file mappings into the new special vma operation: ->remap_pages(). Filesystems must implement this method to get non-linear mapping support, if it uses filemap_fault() then generic_file_remap_pages() can be used. Now device drivers can implement this method and obtain nonlinear vma support. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> #arch/tile Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xattr: extract simple_xattr code from tmpfsAristeu Rozanski2012-08-241-158/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extract in-memory xattr APIs from tmpfs. Will be used by cgroup. $ size vmlinux.o text data bss dec hex filename 4658782 880729 5195032 10734543 a3cbcf vmlinux.o $ size vmlinux.o text data bss dec hex filename 4658957 880729 5195032 10734718 a3cc7e vmlinux.o v7: - checkpatch warnings fixed - Implement the changes requested by Hugh Dickins: - make simple_xattrs_init and simple_xattrs_free inline - get rid of locking and list reinitialization in simple_xattrs_free, they're not needed v6: - no changes v5: - no changes v4: - move simple_xattrs_free() to fs/xattr.c v3: - in kmem_xattrs_free(), reinitialize the list - use simple_xattr_* prefix - introduce simple_xattr_add() to prevent direct list usage Original-patch-by: Li Zefan <lizefan@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Lennart Poettering <lpoetter@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Aristeu Rozanski <aris@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* tmpfs: distribute interleave better across nodesNathan Zimmer2012-07-311-2/+4
| | | | | | | | | | | | | | | | | | | | When tmpfs has the interleave memory policy, it always starts allocating for each file from node 0 at offset 0. When there are many small files, the lower nodes fill up disproportionately. This patch spreads out node usage by starting files at nodes other than 0, by using the inode number to bias the starting node for interleave. Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* don't pass nameidata to ->create()Al Viro2012-07-141-1/+1
| | | | | | | | boolean "does it have to be exclusive?" flag is passed instead; Local filesystem should just ignore it - the object is guaranteed not to be there yet. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* shmem: cleanup shmem_add_to_page_cacheHugh Dickins2012-07-111-30/+28
| | | | | | | | | | | | | | | | | shmem_add_to_page_cache() has three callsites, but only one of them wants the radix_tree_preload() (an exceptional entry guarantees that the radix tree node is present in the other cases), and only that site can achieve mem_cgroup_uncharge_cache_page() (PageSwapCache makes it a no-op in the other cases). We did it this way originally to reflect add_to_page_cache_locked(); but it's confusing now, so move the radix_tree preloading and mem_cgroup uncharging to that one caller. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* shmem: fix negative rss in memcg memory.statHugh Dickins2012-07-111-12/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When adding the page_private checks before calling shmem_replace_page(), I did realize that there is a further race, but thought it too unlikely to need a hurried fix. But independently I've been chasing why a mem cgroup's memory.stat sometimes shows negative rss after all tasks have gone: I expected it to be a stats gathering bug, but actually it's shmem swapping's fault. It's an old surprise, that when you lock_page(lookup_swap_cache(swap)), the page may have been removed from swapcache before getting the lock; or it may have been freed and reused and be back in swapcache; and it can even be using the same swap location as before (page_private same). The swapoff case is already secure against this (swap cannot be reused until the whole area has been swapped off, and a new swapped on); and shmem_getpage_gfp() is protected by shmem_add_to_page_cache()'s check for the expected radix_tree entry - but a little too late. By that time, we might have already decided to shmem_replace_page(): I don't know of a problem from that, but I'd feel more at ease not to do so spuriously. And we have already done mem_cgroup_cache_charge(), on perhaps the wrong mem cgroup: and this charge is not then undone on the error path, because PageSwapCache ends up preventing that. It's this last case which causes the occasional negative rss in memory.stat: the page is charged here as cache, but (sometimes) found to be anon when eventually it's uncharged - and in between, it's an undeserved charge on the wrong memcg. Fix this by adding an earlier check on the radix_tree entry: it's inelegant to descend the tree twice, but swapping is not the fast path, and a better solution would need a pair (try+commit) of memcg calls, and a rework of shmem_replace_page() to keep out of the swapcache. We can use the added shmem_confirm_swap() function to replace the find_get_page+page_cache_release we were already doing on the error path. And add a comment on that -EEXIST: it seems a peculiar errno to be using, but originates from its use in radix_tree_insert(). [It can be surprising to see positive rss left in a memcg's memory.stat after all tasks have gone, since it is supposed to count anonymous but not shmem. Aside from sharing anon pages via fork with a task in some other memcg, it often happens after swapping: because a swap page can't be freed while under writeback, nor while locked. So it's not an error, and these residual pages are easily freed once pressure demands.] Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: revert SEEK_DATA and SEEK_HOLEHugh Dickins2012-07-111-93/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Revert 4fb5ef089b28 ("tmpfs: support SEEK_DATA and SEEK_HOLE"). I believe it's correct, and it's been nice to have from rc1 to rc6; but as the original commit said: I don't know who actually uses SEEK_DATA or SEEK_HOLE, and whether it would be of any use to them on tmpfs. This code adds 92 lines and 752 bytes on x86_64 - is that bloat or worthwhile? Nobody asked for it, so I conclude that it's bloat: let's revert tmpfs to the dumb generic support for v3.5. We can always reinstate it later if useful, and anyone needing it in a hurry can just get it out of git. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Josef Bacik <josef@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andreas Dilger <adilger@dilger.ca> Cc: Dave Chinner <david@fromorbit.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Jeff liu <jeff.liu@oracle.com> Cc: Chris Mason <chris.mason@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2012-07-031-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block bits from Jens Axboe: "As vacation is coming up, thought I'd better get rid of my pending changes in my for-linus branch for this iteration. It contains: - Two patches for mtip32xx. Killing a non-compliant sysfs interface and moving it to debugfs, where it belongs. - A few patches from Asias. Two legit bug fixes, and one killing an interface that is no longer in use. - A patch from Jan, making the annoying partition ioctl warning a bit less annoying, by restricting it to !CAP_SYS_RAWIO only. - Three bug fixes for drbd from Lars Ellenberg. - A fix for an old regression for umem, it hasn't really worked since the plugging scheme was changed in 3.0. - A few fixes from Tejun. - A splice fix from Eric Dumazet, fixing an issue with pipe resizing." * 'for-linus' of git://git.kernel.dk/linux-block: scsi: Silence unnecessary warnings about ioctl to partition block: Drop dead function blk_abort_queue() block: Mitigate lock unbalance caused by lock switching block: Avoid missed wakeup in request waitqueue umem: fix up unplugging splice: fix racy pipe->buffers uses drbd: fix null pointer dereference with on-congestion policy when diskless drbd: fix list corruption by failing but already aborted reads drbd: fix access of unallocated pages and kernel panic xen/blkfront: Add WARN to deal with misbehaving backends. blkcg: drop local variable @q from blkg_destroy() mtip32xx: Create debugfs entries for troubleshooting mtip32xx: Remove 'registers' and 'flags' from sysfs blkcg: fix blkg_alloc() failure path block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED block: fix return value on cfq_init() failure mtip32xx: Remove version.h header file inclusion xen/blkback: Copy id field when doing BLKIF_DISCARD.
| * splice: fix racy pipe->buffers usesEric Dumazet2012-06-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered by splice_shrink_spd() called from vmsplice_to_pipe() commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes) added capability to adjust pipe->buffers. Problem is some paths don't hold pipe mutex and assume pipe->buffers doesn't change for their duration. Fix this by adding nr_pages_max field in struct splice_pipe_desc, and use it in place of pipe->buffers where appropriate. splice_shrink_spd() loses its struct pipe_inode_info argument. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Tom Herbert <therbert@google.com> Cc: stable <stable@vger.kernel.org> # 2.6.35 Tested-by: Dave Jones <davej@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | shmem: replace_page must flush_dcache and othersHugh Dickins2012-06-071-20/+37
|/ | | | | | | | | | | | | | | | | | | | | | | | | Commit bde05d1ccd51 ("shmem: replace page if mapping excludes its zone") is not at all likely to break for anyone, but it was an earlier version from before review feedback was incorporated. Fix that up now. * shmem_replace_page must flush_dcache_page after copy_highpage [akpm] * Expand comment on why shmem_unuse_inode needs page_swapcount [akpm] * Remove excess of VM_BUG_ONs from shmem_replace_page [wangcong] * Check page_private matches swap before calling shmem_replace_page [hughd] * shmem_replace_page allow for unexpected race in radix_tree lookup [hughd] Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Stephane Marchesin <marcheu@chromium.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Rob Clark <rob.clark@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-06-011-4/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs changes from Al Viro. "A lot of misc stuff. The obvious groups: * Miklos' atomic_open series; kills the damn abuse of ->d_revalidate() by NFS, which was the major stumbling block for all work in that area. * ripping security_file_mmap() and dealing with deadlocks in the area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in general. * ->encode_fh() switched to saner API; insane fake dentry in mm/cleancache.c gone. * assorted annotations in fs (endianness, __user) * parts of Artem's ->s_dirty work (jff2 and reiserfs parts) * ->update_time() work from Josef. * other bits and pieces all over the place. Normally it would've been in two or three pull requests, but signal.git stuff had eaten a lot of time during this cycle ;-/" Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the 'truncate_range' inode method was removed by the VM changes, the VFS update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due to sparse fix added twice, with other changes nearby). * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits) nfs: don't open in ->d_revalidate vfs: retry last component if opening stale dentry vfs: nameidata_to_filp(): don't throw away file on error vfs: nameidata_to_filp(): inline __dentry_open() vfs: do_dentry_open(): don't put filp vfs: split __dentry_open() vfs: do_last() common post lookup vfs: do_last(): add audit_inode before open vfs: do_last(): only return EISDIR for O_CREAT vfs: do_last(): check LOOKUP_DIRECTORY vfs: do_last(): make ENOENT exit RCU safe vfs: make follow_link check RCU safe vfs: do_last(): use inode variable vfs: do_last(): inline walk_component() vfs: do_last(): make exit RCU safe vfs: split do_lookup() Btrfs: move over to use ->update_time fs: introduce inode operation ->update_time reiserfs: get rid of resierfs_sync_super reiserfs: mark the superblock as dirty a bit later ...
| * ->encode_fh() API changeAl Viro2012-05-291-4/+2
| | | | | | | | | | | | | | | | | | pass inode + parent's inode or NULL instead of dentry + bool saying whether we want the parent or not. NOTE: that needs ceph fix folded in. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | tmpfs: support SEEK_DATA and SEEK_HOLEHugh Dickins2012-05-291-1/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's quite easy for tmpfs to scan the radix_tree to support llseek's new SEEK_DATA and SEEK_HOLE options: so add them while the minutiae are still on my mind (in particular, the !PageUptodate-ness of pages fallocated but still unwritten). But I don't know who actually uses SEEK_DATA or SEEK_HOLE, and whether it would be of any use to them on tmpfs. This code adds 92 lines and 752 bytes on x86_64 - is that bloat or worthwhile? [akpm@linux-foundation.org: fix warning with CONFIG_TMPFS=n] Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Josef Bacik <josef@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andreas Dilger <adilger@dilger.ca> Cc: Dave Chinner <david@fromorbit.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Jeff liu <jeff.liu@oracle.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: quit when fallocate fills memoryHugh Dickins2012-05-291-2/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As it stands, a large fallocate() on tmpfs is liable to fill memory with pages, freed on failure except when they run into swap, at which point they become fixed into the file despite the failure. That feels quite wrong, to be consuming resources precisely when they're in short supply. Go the other way instead: shmem_fallocate() indicate the range it has fallocated to shmem_writepage(), keeping count of pages it's allocating; shmem_writepage() reactivate instead of swapping out pages fallocated by this syscall (but happily swap out those from earlier occasions), keeping count; shmem_fallocate() compare counts and give up once the reactivated pages have started to coming back to writepage (approximately: some zones would in fact recycle faster than others). This is a little unusual, but works well: although we could consider the failure to swap as a bug, and fix it later with SWAP_MAP_FALLOC handling added in swapfile.c and memcontrol.c, I doubt that we shall ever want to. (If there's no swap, an over-large fallocate() on tmpfs is limited in the same way as writing: stopped by rlimit, or by tmpfs mount size if that was set sensibly, or by __vm_enough_memory() heuristics if OVERCOMMIT_GUESS or OVERCOMMIT_NEVER. If OVERCOMMIT_ALWAYS, then it is liable to OOM-kill others as writing would, but stops and frees if interrupted.) Now that everything is freed on failure, we can then skip updating ctime. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: undo fallocation on failureHugh Dickins2012-05-291-33/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the previous episode, we left the already-fallocated pages attached to the file when shmem_fallocate() fails part way through. Now try to do better, by extending the earlier optimization of !Uptodate pages (then always under page lock) to !Uptodate pages (outside of page lock), representing fallocated pages. And don't waste time clearing them at the time of fallocate(), leave that until later if necessary. Adapt shmem_truncate_range() to shmem_undo_range(), so that a failing fallocate can recognize and remove precisely those !Uptodate allocations which it added (and were not independently allocated by racing tasks). But unless we start playing with swapfile.c and memcontrol.c too, once one of our fallocated pages reaches shmem_writepage(), we do then have to instantiate it as an ordinarily allocated page, before swapping out. This is unsatisfactory, but improved in the next episode. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: support fallocate preallocationHugh Dickins2012-05-291-1/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The systemd plumbers expressed a wish that tmpfs support preallocation. Cong Wang wrote a patch, but several kernel guys expressed scepticism: https://lkml.org/lkml/2011/11/18/137 Christoph Hellwig: What for exactly? Please explain why preallocating on tmpfs would make any sense. Kay Sievers: To be able to safely use mmap(), regarding SIGBUS, on files on the /dev/shm filesystem. The glibc fallback loop for -ENOSYS [or -EOPNOTSUPP] on fallocate is just ugly. Hugh Dickins: If tmpfs is going to support fallocate(FALLOC_FL_PUNCH_HOLE), it would seem perverse to permit the deallocation but fail the allocation. Christoph Hellwig: Agreed. Now that we do have shmem_fallocate() for hole-punching, plumb in basic support for preallocation mode too. It's fairly straightforward (though quite a few details needed attention), except for when it fails part way through. What a pity that fallocate(2) was not specified to return the length allocated, permitting short fallocations! As it is, when it fails part way through, we ought to free what has just been allocated by this system call; but must be very sure not to free any allocated earlier, or any allocated by racing accesses (not all excluded by i_mutex). But we cannot distinguish them: so in this patch simply leak allocations on partial failure (they will be freed later if the file is removed). An attractive alternative approach would have been for fallocate() not to allocate pages at all, but note reservations by entries in the radix-tree. But that would give less assurance, and, critically, would be hard to fit with mem cgroups (who owns the reservations?): allocating pages lets fallocate() behave in just the same way as write(). Based-on-patch-by: Cong Wang <amwang@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/fs: remove truncate_rangeHugh Dickins2012-05-291-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove vmtruncate_range(), and remove the truncate_range method from struct inode_operations: only tmpfs ever supported it, and tmpfs has now converted over to using the fallocate method of file_operations. Update Documentation accordingly, adding (setlease and) fallocate lines. And while we're in mm.h, remove duplicate declarations of shmem_lock() and shmem_file_setup(): everyone is now using the ones in shmem_fs.h. Based-on-patch-by: Cong Wang <amwang@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: support fallocate FALLOC_FL_PUNCH_HOLEHugh Dickins2012-05-291-11/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tmpfs has supported hole-punching since 2.6.16, via madvise(,,MADV_REMOVE). But nowadays fallocate(,FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE,,) is the agreed way to punch holes. So add shmem_fallocate() to support that, and tweak shmem_truncate_range() to support partial pages at both the beginning and end of range (never needed for madvise, which demands rounded addr and rounds up length). Based-on-patch-by: Cong Wang <amwang@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Cong Wang <amwang@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: optimize clearing when writingHugh Dickins2012-05-291-3/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nick proposed years ago that tmpfs should avoid clearing its pages where write will overwrite them with new data, as ramfs has long done. But I messed it up and just got bad data. Tried again recently, it works fine. Here's time output for writing 4GiB 16 times on this Core i5 laptop: before: real 0m21.169s user 0m0.028s sys 0m21.057s real 0m21.382s user 0m0.016s sys 0m21.289s real 0m21.311s user 0m0.020s sys 0m21.217s after: real 0m18.273s user 0m0.032s sys 0m18.165s real 0m18.354s user 0m0.020s sys 0m18.265s real 0m18.440s user 0m0.032s sys 0m18.337s ramfs: real 0m16.860s user 0m0.028s sys 0m16.765s real 0m17.382s user 0m0.040s sys 0m17.273s real 0m17.133s user 0m0.044s sys 0m17.021s Yes, I have done perf reports, but they need more explanation than they deserve: in summary, clear_page vanishes, its cache loading shifts into copy_user_generic_unrolled; shmem_getpage_gfp goes down, and surprisingly mark_page_accessed goes way up - I think because they are respectively where the cache gets to be reloaded after being purged by clear or copy. Suggested-by: Nick Piggin <npiggin@gmail.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tmpfs: enable NOSEC optimizationHugh Dickins2012-05-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Let tmpfs into the NOSEC optimization (avoiding file_remove_suid() overhead on most common writes): set MS_NOSEC on its superblocks. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | shmem: replace page if mapping excludes its zoneHugh Dickins2012-05-291-19/+122
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The GMA500 GPU driver uses GEM shmem objects, but with a new twist: the backing RAM has to be below 4GB. Not a problem while the boards supported only 4GB: but now Intel's D2700MUD boards support 8GB, and their GMA3600 is managed by the GMA500 driver. shmem/tmpfs has never pretended to support hardware restrictions on the backing memory, but it might have appeared to do so before v3.1, and even now it works fine until a page is swapped out then back in. When read_cache_page_gfp() supplied a freshly allocated page for copy, that compensated for whatever choice might have been made by earlier swapin readahead; but swapoff was likely to destroy the illusion. We'd like to continue to support GMA500, so now add a new shmem_should_replace_page() check on the zone when about to move a page from swapcache to filecache (in swapin and swapoff cases), with shmem_replace_page() to allocate and substitute a suitable page (given gma500/gem.c's mapping_set_gfp_mask GFP_KERNEL | __GFP_DMA32). This does involve a minor extension to mem_cgroup_replace_page_cache() (the page may or may not have already been charged); and I've removed a comment and call to mem_cgroup_uncharge_cache_page(), which in fact is always a no-op while PageSwapCache. Also removed optimization of an unlikely path in shmem_getpage_gfp(), now that we need to check PageSwapCache more carefully (a racing caller might already have made the copy). And at one point shmem_unuse_inode() needs to use the hitherto private page_swapcount(), to guard against racing with inode eviction. It would make sense to extend shmem_should_replace_page(), to cover cpuset and NUMA mempolicy restrictions too, but set that aside for now: needs a cleanup of shmem mempolicy handling, and more testing, and ought to handle swap faults in do_swap_page() as well as shmem. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Stephane Marchesin <marcheu@chromium.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Rob Clark <rob.clark@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linuxLinus Torvalds2012-05-281-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull writeback tree from Wu Fengguang: "Mainly from Jan Kara to avoid iput() in the flusher threads." * tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Avoid iput() from flusher thread vfs: Rename end_writeback() to clear_inode() vfs: Move waiting for inode writeback from end_writeback() to evict_inode() writeback: Refactor writeback_single_inode() writeback: Remove wb->list_lock from writeback_single_inode() writeback: Separate inode requeueing after writeback writeback: Move I_DIRTY_PAGES handling writeback: Move requeueing when I_SYNC set to writeback_sb_inodes() writeback: Move clearing of I_SYNC into inode_sync_complete() writeback: initialize global_dirty_limit fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds mm: page-writeback.c: local functions should not be exposed globally
| * vfs: Rename end_writeback() to clear_inode()Jan Kara2012-05-061-1/+1
| | | | | | | | | | | | | | | | | | After we moved inode_sync_wait() from end_writeback() it doesn't make sense to call the function end_writeback() anymore. Rename it to clear_inode() which well says what the function really does - set I_CLEAR flag. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
* | userns: Convert tmpfs to use kuid and kgid where appropriateEric W. Biederman2012-05-151-6/+16
|/ | | | | Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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