Re: the "read" syscall sees partial effects of the "write" syscall

er-page basis for buffered IO. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCHv3 1/1] ext4: Optimize file overwrites

be seen in random writes (overwrite). Also bcoz this optimizes > away the spinlock contention during jbd2 slab cache allocation > (jbd2_journal_handle). On x86 VM, ~2x perf improvement was observed. > > Reported-by: Dan Williams > Suggested-by: Jan Kara > Signed-off-by: Ritesh

Re: [PATCH 1/4] mm: Trial do_wp_page() simplification

ake a alot of driver patches to sort it all > out. I somewhat fear that some of the users of pin_user_pages() don't bother with pinned_vm accounting exactly because they don't have mm_struct on unpin... Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH 1/4] mm: Trial do_wp_page() simplification

need to unaccount on unpin. And that can happen from a different task context (e.g. IRQ handler for direct IO) so we won't have proper mm_struct available. > Could we move pinned_vm out of the drivers/rdma subsystem? I'd love to because IMO it's a mess... Honza -- Jan Kara SUSE Labs, CR

Re: [RFC PATCH] locking/percpu-rwsem: use this_cpu_{inc|dec}() for read_count

hat we could add 'read_count_in_irq' to percpu_rw_semaphore. So callers in normal context would use read_count and callers in irq context would use read_count_in_irq. And the writer side would sum over both but we don't care about performance of that one much. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH 06/12] block: lift setting the readahead size into the block layer

/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -1427,10 +1427,6 @@ static int cached_dev_init(struct cached_dev *dc, > unsigned int block_size) > if (ret) > return ret; > > - dc->disk.disk->queue->backing_dev_info->ra_pages = > - max(dc->disk.disk->queue->backing_dev_info->ra_pages, > - q->backing_dev_info->ra_pages); > - So bcache is basically stacking readahead here on top of underlying cache device. I don't see this being replicated by your patch so it is lost now? Probably this should be replaced by properly inheriting optimal IO size? Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH 04/12] bdi: initialize ->ra_pages and ->io_pages in bdi_init

#x27;t this be more logical in bdi_init() than in bdi_alloc()? Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH 03/12] drbd: remove RB_CONGESTED_REMOTE

..6a8286132751df 100644 > --- a/include/linux/drbd.h > +++ b/include/linux/drbd.h > @@ -94,7 +94,6 @@ enum drbd_read_balancing { > RB_PREFER_REMOTE, > RB_ROUND_ROBIN, > RB_LEAST_PENDING, > - RB_CONGESTED_REMOTE, > RB_32K_STRIPING, > RB_64K_STRIPING, > RB_128K_STRIPING, > -- > 2.28.0 > -- Jan Kara SUSE Labs, CR

Re: [PATCH 02/12] drbd: remove dead code in device_to_statistics

On Thu 10-09-20 16:48:22, Christoph Hellwig wrote: > Ever since the switch to blk-mq, a lower device not used for VM > writeback will not be marked congested, so the check will never > trigger. > > Signed-off-by: Christoph Hellwig Looks good to me. You can add: Review

Re: [PATCH 01/12] fs: remove the unused SB_I_MULTIROOT flag

On Thu 10-09-20 16:48:21, Christoph Hellwig wrote: > The last user of SB_I_MULTIROOT is disappeared with commit f2aedb713c28 > ("NFS: Add fs_context support.") > > Signed-off-by: Christoph Hellwig > Reviewed-by: Johannes Thumshirn Nice. You can ad

Re: [PATCH 07/12] bdi: remove BDI_CAP_CGROUP_WRITEBACK

which always supports cgroup writeback. > > Signed-off-by: Christoph Hellwig > Reviewed-by: Johannes Thumshirn Makes sense. You can add: Reviewed-by: Jan Kara Honza > --- > block/blk-core.c| 1 - > f

Re: [PATCH 08/12] bdi: remove BDI_CAP_SYNCHRONOUS_IO

ond > set of block_device_operations as it can switch between modes that > actually support ->rw_page and those who don't. > > Signed-off-by: Christoph Hellwig The patch looks good to me. You can add: Reviewed-by: Jan Kara Hon

Re: [PATCH 12/12] bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag

eck the flag. > > Signed-off-by: Christoph Hellwig Looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/9p/vfs_file.c| 2 +- > fs/fs-writeback.c | 7 +++--- > in

Re: [PATCH 11/12] bdi: invert BDI_CAP_NO_ACCT_WB

wig The patch looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/fuse/inode.c | 3 ++- > include/linux/backing-dev.h | 13 +++-- > mm/backing-dev.c| 1 + > mm

Re: [PATCH 10/12] bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag

ble_pages_required attribute is not nice but probably it isn't widely used. Maybe the deprecation message can even mention to use the queue attribute? Otherwise the patch looks good to me so feel free to add: Reviewed-by: Jan Kara Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH 09/12] mm: use SWP_SYNCHRONOUS_IO more intelligently

On Thu 10-09-20 16:48:29, Christoph Hellwig wrote: > There is no point in trying to call bdev_read_page if SWP_SYNCHRONOUS_IO > is not set, as the device won't support it. > > Signed-off-by: Christoph Hellwig Looks good to me. You can add: Revi

Re: More filesystem need this fix (xfs: use MMAPLOCK around filemap_map_pages())

On Thu 17-09-20 08:37:17, Nikolay Borisov wrote: > On 17.09.20 г. 4:44 ч., Dave Chinner wrote: > > On Wed, Sep 16, 2020 at 05:58:51PM +0200, Jan Kara wrote: > >> On Sat 12-09-20 09:19:11, Amir Goldstein wrote: > >>> On Tue, Jun 23, 2020 at 8:21 AM Dave Chinne

Re: More filesystem need this fix (xfs: use MMAPLOCK around filemap_map_pages())

handler from fs POV and does not need protection from hole punching (current serialization on page lock and checking of page->mapping is enough). That being said I agree this is subtle and the moment someone adds e.g. a readahead call into filemap_map_pages() we have a real problem. I'm not sure how to prevent this risk... Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] reiserfs: only call unlock_new_inode() if I_NEW

ot+187510916eb6a1459...@syzkaller.appspotmail.com > > > Signed-off-by: Eric Biggers > > > > Anyone interested in taking this patch? > > Jan, you seem to be taking some reiserfs patches... Any interest in > taking this one? Sure, the patch looks good to me so I've added it to my tree. Thanks! Honza -- Jan Kara SUSE Labs, CR

Re: More filesystem need this fix (xfs: use MMAPLOCK around filemap_map_pages())

zation between page cache and various fs operations is just too complex with too many special corner cases. But that's difficult to change while keeping all the features and performance. So the best realistic answer I have (and this is not meant to discourage anybody from trying to implement a simpler scheme of page-cache - filesystem interaction :) is that we should have added a fstest when XFS fix landed which would then hopefully catch attention of other fs maintainers (at least those that do run fstest). Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH -next] ext2: Fix some kernel-doc warnings in balloc.c

window which includes the goal, or the previous one > @@ -859,7 +859,7 @@ static int find_next_reservable_window( > * > * failed: we failed to find a reservation window in this group > * > - * @rsv: the reservation > + * @my_rsv: the reservation > * > * @grp_goal: The goal (group-relative). It is where the search for a > * free reservable space should start from. > -- > 2.17.1 > -- Jan Kara SUSE Labs, CR

Re: Question: Why is there no notification when a file is opened using filp_open()?

On Wed 09-09-20 19:03:07, Amir Goldstein wrote: > On Wed, Sep 9, 2020 at 2:11 PM Jan Kara wrote: > > > > On Wed 09-09-20 10:36:57, Amir Goldstein wrote: > > > On Wed, Sep 9, 2020 at 10:00 AM Xiaoming Ni wrote: > > > > > > > > On 2020/9/9 11:44, Ami

Re: [PATCH] fsync.2: ERRORS: add EIO and ENOSPC

On Wed 09-09-20 13:58:50, Michael Kerrisk (man-pages) wrote: > [CC += Neil, since he wrote the text we're talking about] > > Hello Jan, > > On 9/9/20 1:21 PM, Jan Kara wrote: > > On Wed 09-09-20 12:52:48, Michael Kerrisk (man-pages) wrote: > >>> So the err

Re: Question: Why is there no notification when a file is opened using filp_open()?

snotify_open() event (most notably io_uring, exec, or do_handle_open) and there are others as Xiaoming found which just don't bother. I'm not sure filp_open() should unconditionally generate fsnotify_open() event as IMO some of those notifications would be more confusing than useful. OTOH it is true that e.g. for core dumping we will generate other fsnotify events such as FSNOTIFY_CLOSE (which is generated in __fput()) so missing FSNOTIFY_OPEN is somewhat confusing. So having some consistency in this (either by generating FSNOTIFY_OPEN or by not generating FSNOTIFY_CLOSE) would be IMO desirable. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] fsync.2: ERRORS: add EIO and ENOSPC

all of the > open file descriptions connected to the inode? Your thoughts? The error gets reported once for each "open file description" of the file (inode) where the error happened. If there are multiple file descriptors pointing to the same open file description, then only one of those fil

Re: [PATCH RESEND] fs: Move @f_count to different cacheline with @f_mode

atomic_long_t f_count; > } __randomize_layout >__attribute__((aligned(4))); /* lest something weird decides that 2 > is OK */ > > -- > 2.7.4 > -- Jan Kara SUSE Labs, CR

Re: [PATCH] fsync.2: ERRORS: add EIO and ENOSPC

on" in manpages) and so EIO / ENOSPC is reported once for each file description of the file that was open before the error happened. Not sure if we want to be so precise in the manpages or if it just confuses people. Anyway your takeway that no error on subsequent fsync() does not mean data was written is correct. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] fs: adjust dirtytime_interval_handler definition to match prototype

->proc_handler") > Cc: Christoph Hellwig > Cc: Al Viro > Signed-off-by: Tobias Klauser Thanks! The patch looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/fs-writeback.c | 2 +- &

Re: [PATCH 1/2] ext2: don't update mtime on COW faults

ext2_dax_fault(struct > ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops); > > up_read(&ei->dax_sem); > - if (vmf->flags & FAULT_FLAG_WRITE) > + if (write) > sb_end_pagefault(inode->i_sb); > return ret; > } > -- Jan Kara SUSE Labs, CR

Re: [PATCH 2/2] xfs: don't update mtime on COW faults

or this and have Jan do one for > ext2, I just applied these two directly as "ObviouslyCorrect(tm)". OK, thanks! Honza -- Jan Kara SUSE Labs, CR

Re: kernel BUG at fs/ext4/inode.c:LINE!

On Fri 28-08-20 12:07:55, Jan Kara wrote: > On Wed 26-08-20 19:48:16, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit:c3d8f220 Merge tag 'kbuild-fixes-v5.9' of git://git.kernel.. > > g

Re: [PATCH v3] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

(sizeof(struct buffer_head *) * nr_groups); > > - > > - if (size <= PAGE_SIZE) > > - bitmap = kzalloc(size, GFP_KERNEL); > > - else > > - bitmap = vzalloc(size); /* TODO: get rid of vzalloc */ > > + int nr_groups = udf_compute_nr_groups(sb, index); > > > > + bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups), > > + GFP_KERNEL); > > if (!bitmap) > > return NULL; > > > > > -- Jan Kara SUSE Labs, CR

Re: kernel BUG at fs/ext4/inode.c:LINE!

ps://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkal...@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches -- Jan Kara SUSE Labs, CR

Re: [PATCH] aio: make aio wait path to account iowait time

care about performance, and want to see a shiny random > number generator, by all means, use io_schedule(). Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] ext4: Fix memleak in add_new_gdb

p_desc and gdb_bh are already referenced from the superblock so you cannot free them, iloc.bh has been released in ext4_mark_iloc_dirty(). Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] aio: make aio wait path to account iowait time

fio > 16294 root 20 0 272404 3624 1872 S 1.0 0.0 0:03.60 fio > 16296 root 20 0 272412 3564 1864 S 1.0 0.0 0:03.60 fio > 16299 root 20 0 272424 3540 1840 S 1.0 0.0 0:03.62 fio > 16301 root 20 0 272432 3568

Re: [PATCH] aio: use wait_for_completion_io() when waiting for completion of io

develop new interface like > io_wait_event_hrtimeout(), then we can use it instead of > wait_event_interruptible_hrtimeout()? Yes, that's what I'd do. Honza > > On 08/27/2020 15:55, Jan Kara wrote: > Hello! &

Re: [PATCH] aio: use wait_for_completion_io() when waiting for completion of io

r patch is rather pointless. Honza > On 08/26/2020 21:23, Jan Kara wrote: > On Wed 05-08-20 09:35:51, Xianting Tian wrote: > > When waiting for the completion of io, we need account iowait time. As > > wait_for_completion() calls schedule_timeout(), which doesn't account >

Re: [PATCH] writeback: clear auto_free in initializaiton

ee = 0, > }; > > if (!bdi_has_dirty_io(bdi) || bdi == &noop_backing_dev_info) > @@ -2538,6 +2536,7 @@ void sync_inodes_sb(struct super_block *sb) > .done = &done, > .reason = WB_REASON_SYNC, > .

Re: [PATCH] aio: use wait_for_completion_io() when waiting for completion of io

tx *ctx, long > min_nr, long nr, >* is destroyed. >*/ > if (!ret) > - wait_for_completion(&wait.comp); > + wait_for_completion_io(&wait.comp); > > return ret; > } > -- > 1.8.3.1 > -- Jan Kara SUSE Labs, CR

Re: [PATCH 6/7] mm: Pass pvec directly to find_get_entries

On Tue 25-08-20 14:28:14, Matthew Wilcox wrote: > On Tue, Aug 25, 2020 at 02:33:24PM +0200, Jan Kara wrote: > > On Mon 24-08-20 18:36:39, Matthew Wilcox wrote: > > > We already have functions in filemap which take a pagevec, eg > > > page_cache_delete_batch() and d

Re: [PATCH 6/7] mm: Pass pvec directly to find_get_entries

On Mon 24-08-20 18:36:39, Matthew Wilcox wrote: > On Mon, Aug 24, 2020 at 06:16:20PM +0200, Jan Kara wrote: > > On Wed 19-08-20 16:05:54, Matthew Wilcox (Oracle) wrote: > > > All callers of find_get_entries() use a pvec, so pass it directly > > > instead of ma

Re: [PATCH 6/7] mm: Pass pvec directly to find_get_entries

-1) > break; > diff --git a/mm/swap.c b/mm/swap.c > index d4e3ba4c967c..40b23300d353 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -1060,9 +1060,7 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec, > struct address_space *mapping, pgoff_t start, pgoff_t end, > pgoff_t *indices) > { > - pvec->nr = find_get_entries(mapping, start, end, PAGEVEC_SIZE, > - pvec->pages, indices); > - return pagevec_count(pvec); > + return find_get_entries(mapping, start, end, pvec, indices); > } > > /** > -- > 2.28.0 > -- Jan Kara SUSE Labs, CR

Re: [PATCH 5/7] mm: Remove nr_entries parameter from pagevec_lookup_entries

On Wed 19-08-20 16:05:53, Matthew Wilcox (Oracle) wrote: > All callers want to fetch the full size of the pvec. > > Signed-off-by: Matthew Wilcox (Oracle) Looks good to me. You can add: Reviewed-by: Jan Kara

Re: [PATCH 4/7] mm: Add an 'end' parameter to pagevec_lookup_entries

On Wed 19-08-20 16:05:52, Matthew Wilcox (Oracle) wrote: > Simplifies the callers and uses the existing functionality of > find_get_entries(). > > Signed-off-by: Matthew Wilcox (Oracle) The patch looks good to me. You can add: Reviewed-

Re: [PATCH 1/4] mm: Trial do_wp_page() simplification

> -*/ > > - page_move_anon_rmap(vmf->page, vma); > > - } > > - unlock_page(vmf->page); > > - wp_page_reuse(vmf); > > - return VM_FAULT_WRITE; > > } > > - unlock_page(vmf->page); > > + /* > > +* Ok, we've got the only map reference, and the only > > +* page count reference, and the page is locked, > > +* it's dark out, and we're wearing sunglasses. Hit it. > > +*/ > > + wp_page_reuse(vmf); > > + unlock_page(page); > > + return VM_FAULT_WRITE; > > } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == > > (VM_WRITE|VM_SHARED))) { > > return wp_page_shared(vmf); > > > -- Jan Kara SUSE Labs, CR

Re: [PATCH] mm: madvise: fix vma user-after-free

ut someone else > acquired the mmap_sem and the vma is gone. > > Releasing mmap_sem after accessing vma should fix the problem. > > Fixes: 692fe62433d4c ("mm: Handle MADV_WILLNEED through vfs_fadvise()") > Reported-by: syzbot+b90df26038d1d5d85...@syzkaller.appspotmai

Re: [PATCH 3/7] mm: Add an 'end' parameter to find_get_entries

On Fri 21-08-20 17:33:06, Matthew Wilcox wrote: > On Fri, Aug 21, 2020 at 06:07:59PM +0200, Jan Kara wrote: > > On Wed 19-08-20 16:05:51, Matthew Wilcox (Oracle) wrote: > > > This simplifies the callers and leads to a more efficient implementation > > > since the XA

Re: [PATCH 3/7] mm: Add an 'end' parameter to find_get_entries

+++ b/mm/swap.c > @@ -1060,7 +1060,7 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec, > pgoff_t start, unsigned nr_entries, > pgoff_t *indices) > { > - pvec->nr = find_get_entries(mapping, start, nr_entries, > + pvec->nr = find_get_entries(mapping, start, ULONG_MAX, nr_entries, > pvec->pages, indices); > return pagevec_count(pvec); > } > -- > 2.28.0 > -- Jan Kara SUSE Labs, CR

Re: [PATCH 1/7] mm: Use pagevec_lookup in shmem_unlock_mapping

> is a simpler function to use than find_get_pages(), so use it instead. > > Signed-off-by: Matthew Wilcox (Oracle) This looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > mm/shmem.c | 11 +-- &

Re: [PATCH v3] mm/gup: Allow real explicit breaking of COW

On Fri 21-08-20 05:27:40, Linus Torvalds wrote: > On Fri, Aug 21, 2020 at 3:13 AM Jan Kara wrote: > > > > > + if (page_mapcount(page) != 1 && page_count(page) != 1) { > > > > So this condition looks strange to me... Did you mean: > > >

Re: [PATCH v3] mm/gup: Allow real explicit breaking of COW

/* > + * Ok, we've got the only map reference, and the only > + * page count reference, and the page is locked, > + * it's dark out, and we're wearing sunglasses. Hit it. > + */ > + wp_page_reuse(vmf); > + unlock_page(page); > + return VM_FAULT_WRITE; > } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == > (VM_WRITE|VM_SHARED))) { > return wp_page_shared(vmf); > -- > 2.28.0.218.gc12ef3d349 > -- Jan Kara SUSE Labs, CR

Re: [PATCH v3 02/18] dax: Create a range version of dax_layout_busy_page()

e of pages do not have any > references (and don't want to unmap all the pages of inode). > > Hence, create a range version of this function named > dax_layout_busy_page_range() which can be used to pass a range which > needs to be unmapped. > > Cc: Dan Williams >

Re: [RFC 1/1] ext4: Optimize ext4 DAX overwrites

set + length - 1) >> blkbits, > EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1; > > - if (flags & IOMAP_WRITE) > + if ((flags & IOMAP_WRITE) && !overwrite) > ret = ext4_iomap_alloc(inode, &map, flags); > else >

Re: [PATCH -next] ext2: remove duplicate include

/ext2/inode.c > > index 80662e1f7889..de6b97612410 100644 > > --- a/fs/ext2/inode.c > > +++ b/fs/ext2/inode.c > > @@ -36,7 +36,6 @@ > > #include > > #include > > #include > > -#include > > #include "ext2.h" > > #include "acl.h" > > #include "xattr.h" > > > -- Jan Kara SUSE Labs, CR

Re: [PATCH v2 01/20] dax: Modify bdev_dax_pgoff() to handle NULL bdev

ned-off-by: Stefan Hajnoczi > Signed-off-by: Vivek Goyal > Cc: Christoph Hellwig > Cc: Dan Williams > Cc: linux-nvd...@lists.01.org This patch looks OK to me. You can add: Reviewed-by: Jan Kara Honza > --- >

Re: [PATCH] ext4: use kmemdup_nul() instead of kstrndup()

har *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts, > + char *s_mount_opts = kmemdup_nul(sbi->s_es->s_mount_opts, > sizeof(sbi->s_es->s_mount_opts), > GFP_KERNEL); > if (!s_mount_opts) > -- > 1.8.3.1 > -- Jan Kara SUSE Labs, CR

Re: [PATCH v2 02/20] dax: Create a range version of dax_layout_busy_page()

or other > + * get_user_pages() usages. > + * > + * It is expected that the filesystem is holding locks to block the > + * establishment of new mappings in this address_space. I.e. it expects > + * to be able to run unmap_mapping_range() and subsequently not race > + * mapping_mapped() becoming true. > + */ > +struct page *dax_layout_busy_page(struct address_space *mapping) > +{ > + return dax_layout_busy_page_range(mapping, 0, 0); Should the 'end' rather be LLONG_MAX? Otherwise the patch looks good to me. Honza -- Jan Kara SUSE Labs, CR

Re: stable rc 4.4 - v4.4.232-33-g0b3898baf614 - build breaks on arm64, arm, x86_64 and i386.

ade because of errors. > make[1]: *** [/linux/Makefile:1006: fs] Error 2 > make[1]: Target 'Image' not remade because of errors. > make: *** [Makefile:152: sub-make] Error 2 > make: Target 'Image' not remade because of errors. > > -- > Linaro LKFT > https://lkft.linaro.org -- Jan Kara SUSE Labs, CR

Re: ext4: fix spelling typos in ext4_mb_initialize_context

On Wed 15-07-20 11:00:44, brookxu wrote: > Fix spelling typos in ext4_mb_initialize_context. > > Signed-off-by: Chunguang Xu Looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- >  fs/ext4/mballoc.c |

Re: [PATCH v4] ext4: fix direct I/O read error

ine is loading the previous index file and is > processing the search request, it can not use buffer io that may squeeze > the previous index file in use from pagecache, so the serch service must > use direct I/O read. > > Please apply this patch on these kernel versions, or please use th

Re: [PATCH v3] ext4: fix direct I/O read error

ree to add: Reviewed-by: Jan Kara Honza > > 发自我的iPhone > > > 在 2020年6月29日，下午5:45，Jiang Ying 写道： > > > > This patch is used to fix ext4 direct I/O read error when > > the read size is not ali

Re: kernel BUG at fs/inode.c:531!

drm_kms_helper > evdev r8169 snd_hda_intel syscopyarea snd_intel_dspcfg realtek > snd_hda_codec libphy crc32_pclmul sysfillrect serio_raw sysimgblt > snd_hwdep fb_sys_fops snd_hda_core drm snd_pcm fan thermal > drm_panel_orientation_quirks snd_timer intel_gtt 8250 agpgart snd > 8250_base ehci_pci serial_core button ehci_hcd video soundcore > i2c_i801 lpc_ich mfd_core mei_me mei loop > [99390.044800] ---[ end trace 2ca57858c52a0ad4 ]--- > > -- > nirinA -- Jan Kara SUSE Labs, CR

Re: [PATCH] ext4: check superblock mapped prior to get write access

struct super_block *sb; > + struct buffer_head *sbh; > + > + sb = handle->h_transaction->t_journal->j_private; > + sbh = EXT4_SB(sb)->s_sbh; > + if (unlikely(!buffer_mapped(sbh))) { > + return -EIO; > + } > + > err = jbd2_journal_get_write_access(handle, bh); > if (err) > ext4_journal_abort_handle(where, line, __func__, bh, > -- > 1.8.3.1 > -- Jan Kara SUSE Labs, CR

Re: [PATCH] ext4: Fix comment typo "the the".

76,7 @@ static int ext4_create_inline_data(handle_t *handle, > len = 0; > } > > - /* Insert the the xttr entry. */ > + /* Insert the xttr entry. */ > i.value = value; > i.value_len = len; > > -- > 2.17.1 > -- Jan Kara SUSE Labs, CR

Re: [PATCH 4/4] quota: simplify the quotactl compat handling

On Mon 27-07-20 16:56:16, Al Viro wrote: > On Mon, Jul 27, 2020 at 02:41:27PM +0200, Jan Kara wrote: > > On Sun 26-07-20 18:04:01, Christoph Hellwig wrote: > > > Fold the misaligned u64 workarounds into the main quotactl flow instead > > > of implementing a sepa

Re: [PATCH 4/4] quota: simplify the quotactl compat handling

so feel free to add: Acked-by: Jan Kara Honza > --- > arch/x86/entry/syscalls/syscall_32.tbl | 2 +- > fs/quota/Kconfig | 5 -- > fs/quota/Makefile |

Re: [PATCH] udf: use common error code for unclean filesystem

c_type); > + > goto out; > } > iinfo->i_unique = 0; > > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) > http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- Jan Kara SUSE Labs, CR

Re: [fsnotify] c738fbabb0: will-it-scale.per_process_ops -9.5% regression

fold fsnotify() call into fsnotify_parent() > 71d734103edf fsnotify: Rearrange fast path to minimise overhead when > there is no watcher > 47aaabdedf36 fanotify: Avoid softlockups when reading many events > > Not only did I not observe a regression with the reported commit, > but t

Re: [PATCH] reiserfs: reiserfs.h: delete a duplicated word

On Sun 19-07-20 17:14:31, Randy Dunlap wrote: > Drop the repeated word "than" in a comment. > > Signed-off-by: Randy Dunlap > Cc: Jan Kara > Cc: Jeff Mahoney > Cc: reiserfs-de...@vger.kernel.org Thanks! Applied.

Re: [PATCH] ext2: ext2.h: fix duplicated word + typos

On Sun 19-07-20 17:13:27, Randy Dunlap wrote: > Change the repeated word "the" in "it the the" to "it is the". > Fix typo "recentl" to "recently". > Fix verb "give" to "gives". > > Signed-of

Re: [PATCH] udf: osta_udf.h: delete a duplicated word

On Sun 19-07-20 17:14:55, Randy Dunlap wrote: > Drop the repeated word "struct" in a comment. > > Signed-off-by: Randy Dunlap > Cc: Jan Kara Thanks! Applied. Honza > --- > fs/udf/osta_udf.h |

Re: [PATCH] jbd2: check bh2jh() before accessing it

more looking at the call stack __jbd2_journal_insert_checkpoint() already holds the journal_head we are interested in so it rather looks like we race with invalidation of the block device buffer cache after NBD device disappeared. There were some changes in the lifetime of the block devices after 4.14. Can you reproduce the issue with some more recent kernel because I suspect the problem may be already fixed. Anyway the right fix is to make sure NBD does not destroy buffers while the filesystem is still using them... > jh = bh2jh(bh); > jh->b_jcount++; > } > Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] jbd2: fix incorrect code style

On Sat 18-07-20 08:57:37, Xianting Tian wrote: > Remove unnecessary blank. > > Signed-off-by: Xianting Tian Looks fine. Feel free to add: Reviewed-by: Jan Kara Honza > --- > fs/jbd2/journal.c | 12 ++-

Re: [PATCH] reiserfs : fix improper free in reiserfs_get_block

ks_needed != 1) > >>kfree(un); > >> > >> Because the kcalloc failure falls back to using unf_single, > >> the if-check for the free is wrong. > > I think you mean "Because clang's static analysis is limited, it > > warns incorrectly a

Re: soft lockup in fanotify_read

lot. That will probably silence the softlockup for you as well (although it's not really fixing the underlying issue). We'll have a look what we can do about this :) Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] udf: Replace HTTP links with HTTPS ones

@@ > * This code is based on version 2.00 of the UDF specification, > * and revision 3 of the ECMA 167 standard [equivalent to ISO 13346]. > *http://www.osta.org/ > - *http://www.ecma.ch/ > - *http://www.iso.org/ > + *https://www.ecma.ch/ > + *https://www.iso.org/ > * > * COPYRIGHT > * This file is distributed under the terms of the GNU General Public > -- > 2.27.0 > -- Jan Kara SUSE Labs, CR

Re: [PATCH] Replace HTTP links with HTTPS ones: DISKQUOTA

t; more > > +https://lwn.net/Articles/208755/ and http://people.suug.ch/~tgr/libnl/ for > > more > > That other link is 404, no reason to keep it around... I've already queued a patch that replaces the second link with a working one... Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] Replace HTTP links with HTTPS ones: DISKQUOTA

uota mini-HOWTO, available from > - <http://www.tldp.org/docs.html#howto>, or the documentation provided > + <https://www.tldp.org/docs.html#howto>, or the documentation provided > with the quota tools. Probably the quota support is only useful for > multi user systems. If unsure, say N. > > -- > 2.27.0 > -- Jan Kara SUSE Labs, CR

Re: [PATCH] ext4: fix spelling mistakes in extents.c

Thanks. The fixes look good. You can add: Reviewed-by: Jan Kara Ted, I think this patch has fallen through the cracks... Honza > --- > fs/ext4/extents.c | 10 +- > 1 file changed, 5 insertions(+), 5 deletions(-) >

Re: memory leak in inotify_update_watch

3>] d_alloc+0x21/0xb0 fs/dcache.c:1788 > [<e0349988>] __lookup_hash+0x67/0xc0 fs/namei.c:1441 > [<907d6c36>] filename_create+0xa5/0x1c0 fs/namei.c:3459 > [<25ebf47f>] user_path_create fs/namei.c:3516 [inline] > [<25ebf47f>] do_symlinkat+0x70/0x180 fs/namei.c:3973 > [<d872d7cc>] do_syscall_64+0x4c/0xe0 arch/x86/entry/common.c:359 > [<5c62d8da>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches -- Jan Kara SUSE Labs, CR

Re: segmentation faults with kernels >v5.8-rc2

eudo inodes > ... > > I double checked by reverting this commit on top of v5.8-rc3 and the > segmentation faults are gone. We've already reverted that commit today... Thanks for report! Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] Revert "fs: Do not check if there is a fsnotify watcher on pseudo inodes"

entry, &anon_ops); > path.mnt = mntget(mnt); > d_instantiate(path.dentry, inode); > - file = alloc_file(&path, flags | FMODE_NONOTIFY, fops); > + file = alloc_file(&path, flags, fops); > if (IS_ERR(file)) { > ihold(inode); > path_put(&path); -- Jan Kara SUSE Labs, CR

Re: Commit 'fs: Do not check if there is a fsnotify watcher on pseudo inodes' breaks chromium here

could get used (possibly accidentally) and so after this Chromium experience I think we just have to revert the change and live with generating notification events for pipes to avoid userspace regressions. Thoughts? Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH v2] fs: Do not check if there is a fsnotify watcher on pseudo inodes

On Mon 29-06-20 08:17:02, Eric Dumazet wrote: > On 6/16/20 12:47 AM, Jan Kara wrote: > > On Mon 15-06-20 19:26:38, Amir Goldstein wrote: > >>> This patch changes alloc_file_pseudo() to always opt out of fsnotify by > >>> setting FMODE_NONOTIFY flag so that no ch

Re: [PATCH] mm: Skip opportunistic reclaim for dma pinned pages

f and then back to LRU list would increase the contention on the LRU list locks and generally cost performance so for short term pins it is not desirable... Otherwise I agree that conceptually it would make some sence although I'm not sure some places wouldn't get confused by e.g. page cache

Re: [PATCH] mm: Skip opportunistic reclaim for dma pinned pages

ck in early > 2018. Even though we don't have the full file lease + pin_user_pages() > solution in place. > > That's because reclaim is what triggers the problems that we saw. And > with this patch, we bail out of reclaim early. I agree that with this change, some races will become much less likely for some usecases. But as you say, it's not a full solution. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH v2] fs: Do not check if there is a fsnotify watcher on pseudo inodes

t's outside the noise so > > while marginal, there is still some small benefit to ignoring fsnotify > > for files allocated via alloc_file_pseudo in some cases. > > > > Signed-off-by: Mel Gorman > > Reviewed-by: Amir Goldstein Thanks for the patch Mel and for review Amir! I've added the patch to my tree with small amendments to the changelog. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH 07/29] fs: fs.h: fix a kernel-doc parameter description

e_sb_err' > > Fixes: 3b0311e7ca71 ("vfs: track per-sb writeback errors and report them to > syncfs") > Signed-off-by: Mauro Carvalho Chehab Thanks for the fix! It looks good to me. You can add: Reviewed-by: Jan Kara

Re: [PATCH] fs: Do not check if there is a fsnotify watcher on pseudo inodes

f there is a need for this. I don't think using fsnotify on pipe inodes is sane in any way. You'd possibly only get the MODIFY or ACCESS events and even those would not be quite reliable because with pipes stuff like splicing etc. is much more common and that currently completely bypasses fsnotify subsystem. So overall I'm fine with completely ignoring fsnotify on such inodes. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH] proc: Use new_inode not new_inode_pseudo

ot;) > Fixes: 021ada7dff22 ("procfs: switch /proc/self away from proc_dir_entry") > Fixes: 51f0885e5415 ("vfs,proc: guarantee unique inodes in /proc") > Signed-off-by: "Eric W. Biederman" Thanks for analysing this! I agree with the analysis and the patch look

Re: [PATCH] fsnotify: Rearrange fast path to minimise overhead when there is no watcher

arent(struct dentry *dentry, __u32 mask, const void > *data, > +extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void > *data, > int data_type); > extern void __fsnotify_inode_delete(struct inode *inode); > extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); > @@ -541,7 +541,7 @@ static inline int fsnotify(struct inode *to_tell, __u32 > mask, const void *data, > return 0; > } > > -static inline int fsnotify_parent(struct dentry *dentry, __u32 mask, > +static inline int __fsnotify_parent(struct dentry *dentry, __u32 mask, > const void *data, int data_type) > { > return 0; -- Jan Kara SUSE Labs, CR

Re: [PATCH v2] block: Fix use-after-free in blkdev_get()

s the reference you pass to it is somewhat subtle and surprising so I think we are better off getting rid of that. Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH v3] block: Fix use-after-free in blkdev_get()

459.409415] > [ 459.409679] Freed by task 1262: > [ 459.410212] __kasan_slab_free+0x129/0x170 > [ 459.410919] kmem_cache_free+0xb2/0x2a0 > [ 459.411564] rcu_process_callbacks+0xbb2/0x2320 > [ 459.412318] __do_softirq+0x225/0x8ac > > Fix this by delaying bdput() to th

Re: [PATCH V11 11/11] fs/xfs: Update xfs_ioctl_setattr_dax_invalidate()

inode evictions? You have to have an equivalent of write access to the file to be able to trigger d_mark_dontcache(). So you can e.g. delete it. Or you could fadvise / madvise regarding its page cache. I don't see the ability to push inode out of cache as stronger than the abilities you already have... Honza -- Jan Kara SUSE Labs, CR

Re: [PATCH v2 1/2] docs: mm/gup: pin_user_pages.rst: add a "case 5"

rivers/vhost/vhost.c > has a "pin, write to page, set page dirty, unpin" case. > > Add a fifth case, to help explain that there is a general pattern > that requires pin_user_pages*() API calls. > > Cc: Vlastimil Babka > Cc: Jan Kara > Cc: Jérôme Glisse > Cc:

Re: [PATCH 2/2] vhost: convert get_user_pages() --> pin_user_pages()

_user_pages.rst > > [2] "Explicit pinning of user-space pages": > https://lwn.net/Articles/807108/ > > Cc: Michael S. Tsirkin > Cc: Jason Wang > Cc: k...@vger.kernel.org > Cc: virtualizat...@lists.linux-foundation.org > Cc: net...@vger.kernel.or

Re: Writeback bug causing writeback stalls

On Fri 29-05-20 21:37:50, Martijn Coenen wrote: > Hi Jan, > > On Fri, May 29, 2020 at 5:20 PM Jan Kara wrote: > > I understand. I have written a fix (attached). Currently its under testing > > together with other cleanups. If everything works fine, I plan to submit >

Re: Writeback bug causing writeback stalls

Hello Martinj! On Wed 27-05-20 10:14:09, Martijn Coenen wrote: > On Mon, May 25, 2020 at 9:31 AM Jan Kara wrote: > > Well, most importantly filesystems like ext4, xfs, btrfs don't hold i_rwsem > > when writing back inode and that's deliberate because of performance. W

Re: [PATCH] reiserfs: Replace kmalloc with kcalloc in the comment

sert becomes > + * If kcalloc failed, max_to_insert becomes >* zero and it means we only have space for > * one block >*/ > -- > 2.9.5 > -- Jan Kara SUSE Labs, CR

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