05 Jun, 2018

1 commit

  • Pull procfs updates from Al Viro:
    "Christoph's proc_create_... cleanups series"

    * 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (44 commits)
    xfs, proc: hide unused xfs procfs helpers
    isdn/gigaset: add back gigaset_procinfo assignment
    proc: update SIZEOF_PDE_INLINE_NAME for the new pde fields
    tty: replace ->proc_fops with ->proc_show
    ide: replace ->proc_fops with ->proc_show
    ide: remove ide_driver_proc_write
    isdn: replace ->proc_fops with ->proc_show
    atm: switch to proc_create_seq_private
    atm: simplify procfs code
    bluetooth: switch to proc_create_seq_data
    netfilter/x_tables: switch to proc_create_seq_private
    netfilter/xt_hashlimit: switch to proc_create_{seq,single}_data
    neigh: switch to proc_create_seq_data
    hostap: switch to proc_create_{seq,single}_data
    bonding: switch to proc_create_seq_data
    rtc/proc: switch to proc_create_single_data
    drbd: switch to proc_create_single
    resource: switch to proc_create_seq_data
    staging/rtl8192u: simplify procfs code
    jfs: simplify procfs code
    ...

    Linus Torvalds
     

22 May, 2018

1 commit


16 May, 2018

1 commit


06 Apr, 2018

1 commit

  • Pass the object size in to fscache_acquire_cookie() and
    fscache_write_page() rather than the netfs providing a callback by which it
    can be received. This makes it easier to update the size of the object
    when a new page is written that extends the object.

    The current object size is also passed by fscache to the check_aux
    function, obviating the need to store it in the aux data.

    Signed-off-by: David Howells
    Acked-by: Anna Schumaker
    Tested-by: Steve Dickson

    David Howells
     

04 Apr, 2018

3 commits

  • Attach copies of the index key and auxiliary data to the fscache cookie so
    that:

    (1) The callbacks to the netfs for this stuff can be eliminated. This
    can simplify things in the cache as the information is still
    available, even after the cache has relinquished the cookie.

    (2) Simplifies the locking requirements of accessing the information as we
    don't have to worry about the netfs object going away on us.

    (3) The cache can do lazy updating of the coherency information on disk.
    As long as the cache is flushed before reboot/poweroff, there's no
    need to update the coherency info on disk every time it changes.

    (4) Cookies can be hashed or put in a tree as the index key is easily
    available. This allows:

    (a) Checks for duplicate cookies can be made at the top fscache layer
    rather than down in the bowels of the cache backend.

    (b) Caching can be added to a netfs object that has a cookie if the
    cache is brought online after the netfs object is allocated.

    A certain amount of space is made in the cookie for inline copies of the
    data, but if it won't fit there, extra memory will be allocated for it.

    The downside of this is that live cache operation requires more memory.

    Signed-off-by: David Howells
    Acked-by: Anna Schumaker
    Tested-by: Steve Dickson

    David Howells
     
  • Add some tracepoints to fscache:

    (*) fscache_cookie - Tracks a cookie's usage count.

    (*) fscache_netfs - Logs registration of a network filesystem, including
    the pointer to the cookie allocated.

    (*) fscache_acquire - Logs cookie acquisition.

    (*) fscache_relinquish - Logs cookie relinquishment.

    (*) fscache_enable - Logs enablement of a cookie.

    (*) fscache_disable - Logs disablement of a cookie.

    (*) fscache_osm - Tracks execution of states in the object state machine.

    and cachefiles:

    (*) cachefiles_ref - Tracks a cachefiles object's usage count.

    (*) cachefiles_lookup - Logs result of lookup_one_len().

    (*) cachefiles_mkdir - Logs result of vfs_mkdir().

    (*) cachefiles_create - Logs result of vfs_create().

    (*) cachefiles_unlink - Logs calls to vfs_unlink().

    (*) cachefiles_rename - Logs calls to vfs_rename().

    (*) cachefiles_mark_active - Logs an object becoming active.

    (*) cachefiles_wait_active - Logs a wait for an old object to be
    destroyed.

    (*) cachefiles_mark_inactive - Logs an object becoming inactive.

    (*) cachefiles_mark_buried - Logs the burial of an object.

    Signed-off-by: David Howells

    David Howells
     
  • Fix a couple of checker warnings in fscache and cachefiles:

    (1) fscache_n_op_requeue is never used, so get rid of it.

    (2) cachefiles_uncache_page() is passed in a lock that it releases, so
    this needs annotating.

    Signed-off-by: David Howells

    David Howells
     

12 Feb, 2018

1 commit

  • This is the mindless scripted replacement of kernel use of POLL*
    variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
    L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
    for f in $L; do sed -i "-es/^\([^\"]*\)\(\\)/\\1E\\2/" $f; done
    done

    with de-mangling cleanups yet to come.

    NOTE! On almost all architectures, the EPOLL* constants have the same
    values as the POLL* constants do. But they keyword here is "almost".
    For various bad reasons they aren't the same, and epoll() doesn't
    actually work quite correctly in some cases due to this on Sparc et al.

    The next patch from Al will sort out the final differences, and we
    should be all done.

    Scripted-by: Al Viro
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

28 Nov, 2017

1 commit


16 Nov, 2017

2 commits

  • As the page free path makes no distinction between cache hot and cold
    pages, there is no real useful ordering of pages in the free list that
    allocation requests can take advantage of. Juding from the users of
    __GFP_COLD, it is likely that a number of them are the result of copying
    other sites instead of actually measuring the impact. Remove the
    __GFP_COLD parameter which simplifies a number of paths in the page
    allocator.

    This is potentially controversial but bear in mind that the size of the
    per-cpu pagelists versus modern cache sizes means that the whole per-cpu
    list can often fit in the L3 cache. Hence, there is only a potential
    benefit for microbenchmarks that alloc/free pages in a tight loop. It's
    even worse when THP is taken into account which has little or no chance
    of getting a cache-hot page as the per-cpu list is bypassed and the
    zeroing of multiple pages will thrash the cache anyway.

    The truncate microbenchmarks are not shown as this patch affects the
    allocation path and not the free path. A page fault microbenchmark was
    tested but it showed no sigificant difference which is not surprising
    given that the __GFP_COLD branches are a miniscule percentage of the
    fault path.

    Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net
    Signed-off-by: Mel Gorman
    Acked-by: Vlastimil Babka
    Cc: Andi Kleen
    Cc: Dave Chinner
    Cc: Dave Hansen
    Cc: Jan Kara
    Cc: Johannes Weiner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     
  • Every pagevec_init user claims the pages being released are hot even in
    cases where it is unlikely the pages are hot. As no one cares about the
    hotness of pages being released to the allocator, just ditch the
    parameter.

    No performance impact is expected as the overhead is marginal. The
    parameter is removed simply because it is a bit stupid to have a useless
    parameter copied everywhere.

    Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net
    Signed-off-by: Mel Gorman
    Acked-by: Vlastimil Babka
    Cc: Andi Kleen
    Cc: Dave Chinner
    Cc: Dave Hansen
    Cc: Jan Kara
    Cc: Johannes Weiner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     

02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

17 Jul, 2017

1 commit

  • Firstly by applying the following with coccinelle's spatch:

    @@ expression SB; @@
    -SB->s_flags & MS_RDONLY
    +sb_rdonly(SB)

    to effect the conversion to sb_rdonly(sb), then by applying:

    @@ expression A, SB; @@
    (
    -(!sb_rdonly(SB)) && A
    +!sb_rdonly(SB) && A
    |
    -A != (sb_rdonly(SB))
    +A != sb_rdonly(SB)
    |
    -A == (sb_rdonly(SB))
    +A == sb_rdonly(SB)
    |
    -!(sb_rdonly(SB))
    +!sb_rdonly(SB)
    |
    -A && (sb_rdonly(SB))
    +A && sb_rdonly(SB)
    |
    -A || (sb_rdonly(SB))
    +A || sb_rdonly(SB)
    |
    -(sb_rdonly(SB)) != A
    +sb_rdonly(SB) != A
    |
    -(sb_rdonly(SB)) == A
    +sb_rdonly(SB) == A
    |
    -(sb_rdonly(SB)) && A
    +sb_rdonly(SB) && A
    |
    -(sb_rdonly(SB)) || A
    +sb_rdonly(SB) || A
    )

    @@ expression A, B, SB; @@
    (
    -(sb_rdonly(SB)) ? 1 : 0
    +sb_rdonly(SB)
    |
    -(sb_rdonly(SB)) ? A : B
    +sb_rdonly(SB) ? A : B
    )

    to remove left over excess bracketage and finally by applying:

    @@ expression A, SB; @@
    (
    -(A & MS_RDONLY) != sb_rdonly(SB)
    +(bool)(A & MS_RDONLY) != sb_rdonly(SB)
    |
    -(A & MS_RDONLY) == sb_rdonly(SB)
    +(bool)(A & MS_RDONLY) == sb_rdonly(SB)
    )

    to make comparisons against the result of sb_rdonly() (which is a bool)
    work correctly.

    Signed-off-by: David Howells

    David Howells
     

20 Jun, 2017

3 commits

  • So I've noticed a number of instances where it was not obvious from the
    code whether ->task_list was for a wait-queue head or a wait-queue entry.

    Furthermore, there's a number of wait-queue users where the lists are
    not for 'tasks' but other entities (poll tables, etc.), in which case
    the 'task_list' name is actively confusing.

    To clear this all up, name the wait-queue head and entry list structure
    fields unambiguously:

    struct wait_queue_head::task_list => ::head
    struct wait_queue_entry::task_list => ::entry

    For example, this code:

    rqw->wait.task_list.next != &wait->task_list

    ... is was pretty unclear (to me) what it's doing, while now it's written this way:

    rqw->wait.head.next != &wait->entry

    ... which makes it pretty clear that we are iterating a list until we see the head.

    Other examples are:

    list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
    list_for_each_entry(wq, &fence->wait.task_list, task_list) {

    ... where it's unclear (to me) what we are iterating, and during review it's
    hard to tell whether it's trying to walk a wait-queue entry (which would be
    a bug), while now it's written as:

    list_for_each_entry_safe(pos, next, &x->head, entry) {
    list_for_each_entry(wq, &fence->wait.head, entry) {

    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • The wait_bit*() types and APIs are mixed into wait.h, but they
    are a pretty orthogonal extension of wait-queues.

    Furthermore, only about 50 kernel files use these APIs, while
    over 1000 use the regular wait-queue functionality.

    So clean up the main wait.h by moving the wait-bit functionality
    out of it, into a separate .h and .c file:

    include/linux/wait_bit.h for types and APIs
    kernel/sched/wait_bit.c for the implementation

    Update all header dependencies.

    This reduces the size of wait.h rather significantly, by about 30%.

    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • Rename:

    wait_queue_t => wait_queue_entry_t

    'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
    but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
    which had to carry the name.

    Start sorting this out by renaming it to 'wait_queue_entry_t'.

    This also allows the real structure name 'struct __wait_queue' to
    lose its double underscore and become 'struct wait_queue_entry',
    which is the more canonical nomenclature for such data types.

    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

02 Mar, 2017

1 commit


11 Oct, 2016

2 commits

  • Pull more vfs updates from Al Viro:
    ">rename2() work from Miklos + current_time() from Deepa"

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
    fs: Replace current_fs_time() with current_time()
    fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
    fs: Replace CURRENT_TIME with current_time() for inode timestamps
    fs: proc: Delete inode time initializations in proc_alloc_inode()
    vfs: Add current_time() api
    vfs: add note about i_op->rename changes to porting
    fs: rename "rename2" i_op to "rename"
    vfs: remove unused i_op->rename
    fs: make remaining filesystems use .rename2
    libfs: support RENAME_NOREPLACE in simple_rename()
    fs: support RENAME_NOREPLACE for local filesystems
    ncpfs: fix unused variable warning

    Linus Torvalds
     
  • Pull vfs xattr updates from Al Viro:
    "xattr stuff from Andreas

    This completes the switch to xattr_handler ->get()/->set() from
    ->getxattr/->setxattr/->removexattr"

    * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
    vfs: Remove {get,set,remove}xattr inode operations
    xattr: Stop calling {get,set,remove}xattr inode operations
    vfs: Check for the IOP_XATTR flag in listxattr
    xattr: Add __vfs_{get,set,remove}xattr helpers
    libfs: Use IOP_XATTR flag for empty directory handling
    vfs: Use IOP_XATTR flag for bad-inode handling
    vfs: Add IOP_XATTR inode operations flag
    vfs: Move xattr_resolve_name to the front of fs/xattr.c
    ecryptfs: Switch to generic xattr handlers
    sockfs: Get rid of getxattr iop
    sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
    kernfs: Switch to generic xattr handlers
    hfs: Switch to generic xattr handlers
    jffs2: Remove jffs2_{get,set,remove}xattr macros
    xattr: Remove unnecessary NULL attribute name check

    Linus Torvalds
     

08 Oct, 2016

1 commit

  • Right now, various places in the kernel check for the existence of
    getxattr, setxattr, and removexattr inode operations and directly call
    those operations. Switch to helper functions and test for the IOP_XATTR
    flag instead.

    Signed-off-by: Andreas Gruenbacher
    Acked-by: James Morris
    Signed-off-by: Al Viro

    Andreas Gruenbacher
     

28 Sep, 2016

1 commit

  • An NULL-pointer dereference happens in cachefiles_mark_object_inactive()
    when it tries to read i_blocks so that it can tell the cachefilesd daemon
    how much space it's making available.

    The problem is that cachefiles_drop_object() calls
    cachefiles_mark_object_inactive() after calling cachefiles_delete_object()
    because the object being marked active staves off attempts to (re-)use the
    file at that filename until after it has been deleted. This means that
    d_inode is NULL by the time we come to try to access it.

    To fix the problem, have the caller of cachefiles_mark_object_inactive()
    supply the number of blocks freed up.

    Without this, the following oops may occur:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
    IP: [] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
    ...
    CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G I ------------ 3.10.0-470.el7.x86_64 #1
    Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011
    Workqueue: fscache_object fscache_object_work_func [fscache]
    task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000
    RIP: 0010:[] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
    RSP: 0018:ffff8800b77c3d70 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034
    RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8
    RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000
    R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600
    R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498
    FS: 0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000
    CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
    CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Stack:
    ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0
    ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658
    ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600
    Call Trace:
    [] cachefiles_drop_object+0x6b/0xf0 [cachefiles]
    [] fscache_drop_object+0xd6/0x1e0 [fscache]
    [] fscache_object_work_func+0xa5/0x200 [fscache]
    [] process_one_work+0x17b/0x470
    [] worker_thread+0x126/0x410
    [] ? rescuer_thread+0x460/0x460
    [] kthread+0xcf/0xe0
    [] ? kthread_create_on_node+0x140/0x140
    [] ret_from_fork+0x58/0x90
    [] ? kthread_create_on_node+0x140/0x140

    The oopsing code shows:

    callq 0xffffffff810af6a0
    mov 0xf8(%r12),%rax
    mov 0x30(%rax),%rax
    mov 0x98(%rax),%rax dentry)->i_blocks

    Fixes: a5b3a80b899bda0f456f1246c4c5a1191ea01519 (CacheFiles: Provide read-and-reset release counters for cachefilesd)
    Reported-by: Jianhong Yin
    Signed-off-by: David Howells
    Reviewed-by: Jeff Layton
    Reviewed-by: Steve Dickson
    cc: stable@vger.kernel.org
    Signed-off-by: Al Viro

    David Howells
     

27 Sep, 2016

2 commits


04 Aug, 2016

1 commit

  • There's a race between cachefiles_mark_object_inactive() and
    cachefiles_cull():

    (1) cachefiles_cull() can't delete a backing file until the cache object
    is marked inactive, but as soon as that's the case it's fair game.

    (2) cachefiles_mark_object_inactive() marks the object as being inactive
    and *only then* reads the i_blocks on the backing inode - but
    cachefiles_cull() might've managed to delete it by this point.

    Fix this by making sure cachefiles_mark_object_inactive() gets any data it
    needs from the backing inode before deactivating the object.

    Without this, the following oops may occur:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
    IP: [] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
    ...
    CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G I ------------ 3.10.0-470.el7.x86_64 #1
    Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011
    Workqueue: fscache_object fscache_object_work_func [fscache]
    task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000
    RIP: 0010:[] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles]
    RSP: 0018:ffff8800b77c3d70 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034
    RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8
    RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000
    R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600
    R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498
    FS: 0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000
    CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
    CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Stack:
    ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0
    ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658
    ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600
    Call Trace:
    [] cachefiles_drop_object+0x6b/0xf0 [cachefiles]
    [] fscache_drop_object+0xd6/0x1e0 [fscache]
    [] fscache_object_work_func+0xa5/0x200 [fscache]
    [] process_one_work+0x17b/0x470
    [] worker_thread+0x126/0x410
    [] ? rescuer_thread+0x460/0x460
    [] kthread+0xcf/0xe0
    [] ? kthread_create_on_node+0x140/0x140
    [] ret_from_fork+0x58/0x90
    [] ? kthread_create_on_node+0x140/0x140

    The oopsing code shows:

    callq 0xffffffff810af6a0
    mov 0xf8(%r12),%rax
    mov 0x30(%rax),%rax
    mov 0x98(%rax),%rax dentry)->i_blocks

    Fixes: a5b3a80b899bda0f456f1246c4c5a1191ea01519 (CacheFiles: Provide read-and-reset release counters for cachefilesd)
    Reported-by: Jianhong Yin
    Signed-off-by: David Howells
    Reviewed-by: Jeff Layton
    Reviewed-by: Steve Dickson
    cc: stable@vger.kernel.org
    Signed-off-by: Al Viro

    David Howells
     

01 Jul, 2016

1 commit


01 Jun, 2016

1 commit

  • __fscache_check_consistency() calls check_consistency() callback
    and return the callback's return value. But the return type of
    check_consistency() is bool. So __fscache_check_consistency()
    return 1 if the cache is inconsistent. This is inconsistent with
    the document.

    Signed-off-by: Yan, Zheng
    Acked-by: David Howells

    Yan, Zheng
     

30 May, 2016

1 commit


05 Apr, 2016

1 commit

  • PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
    ago with promise that one day it will be possible to implement page
    cache with bigger chunks than PAGE_SIZE.

    This promise never materialized. And unlikely will.

    We have many places where PAGE_CACHE_SIZE assumed to be equal to
    PAGE_SIZE. And it's constant source of confusion on whether
    PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
    especially on the border between fs and mm.

    Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
    breakage to be doable.

    Let's stop pretending that pages in page cache are special. They are
    not.

    The changes are pretty straight-forward:

    - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

    - page_cache_get() -> get_page();

    - page_cache_release() -> put_page();

    This patch contains automated changes generated with coccinelle using
    script below. For some reason, coccinelle doesn't patch header files.
    I've called spatch for them manually.

    The only adjustment after coccinelle is revert of changes to
    PAGE_CAHCE_ALIGN definition: we are going to drop it later.

    There are few places in the code where coccinelle didn't reach. I'll
    fix them manually in a separate patch. Comments and documentation also
    will be addressed with the separate patch.

    virtual patch

    @@
    expression E;
    @@
    - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    expression E;
    @@
    - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    @@
    - PAGE_CACHE_SHIFT
    + PAGE_SHIFT

    @@
    @@
    - PAGE_CACHE_SIZE
    + PAGE_SIZE

    @@
    @@
    - PAGE_CACHE_MASK
    + PAGE_MASK

    @@
    expression E;
    @@
    - PAGE_CACHE_ALIGN(E)
    + PAGE_ALIGN(E)

    @@
    expression E;
    @@
    - page_cache_get(E)
    + get_page(E)

    @@
    expression E;
    @@
    - page_cache_release(E)
    + put_page(E)

    Signed-off-by: Kirill A. Shutemov
    Acked-by: Michal Hocko
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     

02 Feb, 2016

1 commit

  • Provide read-and-reset objects- and blocks-released counters for cachefilesd
    to use to work out whether there's anything new that can be culled.

    One of the problems cachefilesd has is that if all the objects in the cache
    are pinned by inodes lying dormant in the kernel inode cache, there isn't
    anything for it to cull. In such a case, it just spins around walking the
    filesystem tree and scanning for something to cull. This eats up a lot of
    CPU time.

    By telling cachefilesd if there have been any releases, the daemon can
    sleep until there is the possibility of something to do.

    cachefilesd finds this information by the following means:

    (1) When the control fd is read, the kernel presents a list of values of
    interest. "freleased=N" and "breleased=N" are added to this list to
    indicate the number of files released and number of blocks released
    since the last read call. At this point the counters are reset.

    (2) POLLIN is signalled if the number of files released becomes greater
    than 0.

    Note that by 'released' it just means that the kernel has released its
    interest in those files for the moment, not necessarily that the files
    should be deleted from the cache.

    Signed-off-by: David Howells
    Reviewed-by: Steve Dickson
    Signed-off-by: Al Viro

    David Howells
     

23 Jan, 2016

1 commit

  • parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
    inode_foo(inode) being mutex_foo(&inode->i_mutex).

    Please, use those for access to ->i_mutex; over the coming cycle
    ->i_mutex will become rwsem, with ->lookup() done with it held
    only shared.

    Signed-off-by: Al Viro

    Al Viro
     

04 Jan, 2016

1 commit


17 Nov, 2015

1 commit

  • fs/cachefiles/rdwr.c: In function ‘cachefiles_write_page’:
    fs/cachefiles/rdwr.c:882: warning: ‘ret’ may be used uninitialized in
    this function

    If the jump to label "error" is taken, "ret" will indeed be
    uninitialized, and random stack data may be printed by the debug code.

    Fixes: 102f4d900c9c8f5e ("FS-Cache: Handle a write to the page immediately beyond the EOF marker")
    Signed-off-by: Geert Uytterhoeven
    Signed-off-by: David Howells
    Signed-off-by: Al Viro

    Geert Uytterhoeven
     

11 Nov, 2015

2 commits

  • Handle a write being requested to the page immediately beyond the EOF
    marker on a cache object. Currently this gets an assertion failure in
    CacheFiles because the EOF marker is used there to encode information about
    a partial page at the EOF - which could lead to an unknown blank spot in
    the file if we extend the file over it.

    The problem is actually in fscache where we check the index of the page
    being written against store_limit. store_limit is set to the number of
    pages that we're allowed to store by fscache_set_store_limit() - which
    means it's one more than the index of the last page we're allowed to store.
    The problem is that we permit writing to a page with an index _equal_ to
    the store limit - when we should reject that case.

    Whilst we're at it, change the triggered assertion in CacheFiles to just
    return -ENOBUFS instead.

    The assertion failure looks something like this:

    CacheFiles: Assertion failed
    1000 < 7b1 is false
    ------------[ cut here ]------------
    kernel BUG at fs/cachefiles/rdwr.c:962!
    ...
    RIP: 0010:[] [] cachefiles_write_page+0x273/0x2d0 [cachefiles]

    Cc: stable@vger.kernel.org # v2.6.31+; earlier - that + backport of a17754f (at least)
    Signed-off-by: David Howells
    Signed-off-by: Al Viro

    David Howells
     
  • cachefiles requires that s_blocksize in the cache is not greater than
    PAGE_SIZE, and performs the check every time a block is accessed.

    Move the test to the place where the file is "opened", where other
    file-validity tests are performed.

    Signed-off-by: NeilBrown
    Signed-off-by: David Howells
    Signed-off-by: Al Viro

    NeilBrown
     

07 Nov, 2015

1 commit

  • __GFP_WAIT was used to signal that the caller was in atomic context and
    could not sleep. Now it is possible to distinguish between true atomic
    context and callers that are not willing to sleep. The latter should
    clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing
    __GFP_WAIT behaves differently, there is a risk that people will clear the
    wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
    indicate what it does -- setting it allows all reclaim activity, clearing
    them prevents it.

    [akpm@linux-foundation.org: fix build]
    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Mel Gorman
    Acked-by: Michal Hocko
    Acked-by: Vlastimil Babka
    Acked-by: Johannes Weiner
    Cc: Christoph Lameter
    Acked-by: David Rientjes
    Cc: Vitaly Wool
    Cc: Rik van Riel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     

24 Jun, 2015

1 commit


16 Apr, 2015

2 commits


24 Feb, 2015

1 commit


23 Feb, 2015

1 commit

  • Fix up the following scripted S_ISDIR/S_ISREG/S_ISLNK conversions (or lack
    thereof) in cachefiles:

    (1) Cachefiles mostly wants to use d_can_lookup() rather than d_is_dir() as
    it doesn't want to deal with automounts in its cache.

    (2) Coccinelle didn't find S_IS* expressions in ASSERT() statements in
    cachefiles.

    Signed-off-by: David Howells
    Signed-off-by: Al Viro

    David Howells