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The only caller already has a folio, so pass it in and use it throughout.
Saves two calls to compound_head().
Link: https://lkml.kernel.org/r/20231215200245.748418-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "Clean up the writeback paths".
Most of these patches verge on the trivial, converting filesystems that
just use block_write_full_page() to use mpage_writepages(). But as we saw
with Christoph's earlier patchset, there can be some "interesting"
gotchas, and I clearly haven't tested the majority of filesystems I've
touched here.
Patches 3 & 4 get rid of a lot of stack usage on architectures with larger
page sizes; 1024 bytes on 64-bit systems with 64KiB pages. It starts to
open the door to larger folio sizes on all architectures, but it's
certainly not enough yet.
Patch 14 is kind of trivial, but it's nice to get that simplification in.
This patch (of 14):
This function has been unused since the removal of bdev_write_page().
Link: https://lkml.kernel.org/r/20231215200245.748418-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231215200245.748418-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Implement the uABI of UFFDIO_MOVE ioctl.
UFFDIO_COPY performs ~20% better than UFFDIO_MOVE when the application
needs pages to be allocated [1]. However, with UFFDIO_MOVE, if pages are
available (in userspace) for recycling, as is usually the case in heap
compaction algorithms, then we can avoid the page allocation and memcpy
(done by UFFDIO_COPY). Also, since the pages are recycled in the
userspace, we avoid the need to release (via madvise) the pages back to
the kernel [2].
We see over 40% reduction (on a Google pixel 6 device) in the compacting
thread's completion time by using UFFDIO_MOVE vs. UFFDIO_COPY. This was
measured using a benchmark that emulates a heap compaction implementation
using userfaultfd (to allow concurrent accesses by application threads).
More details of the usecase are explained in [2]. Furthermore,
UFFDIO_MOVE enables moving swapped-out pages without touching them within
the same vma. Today, it can only be done by mremap, however it forces
splitting the vma.
[1] https://lore.kernel.org/all/1425575884-2574-1-git-send-email-aarcange@redhat.com/
[2] https://lore.kernel.org/linux-mm/CA+EESO4uO84SSnBhArH4HvLNhaUQ5nZKNKXqxRCyjniNVjp0Aw@mail.gmail.com/
Update for the ioctl_userfaultfd(2) manpage:
UFFDIO_MOVE
(Since Linux xxx) Move a continuous memory chunk into the
userfault registered range and optionally wake up the blocked
thread. The source and destination addresses and the number of
bytes to move are specified by the src, dst, and len fields of
the uffdio_move structure pointed to by argp:
struct uffdio_move {
__u64 dst; /* Destination of move */
__u64 src; /* Source of move */
__u64 len; /* Number of bytes to move */
__u64 mode; /* Flags controlling behavior of move */
__s64 move; /* Number of bytes moved, or negated error */
};
The following value may be bitwise ORed in mode to change the
behavior of the UFFDIO_MOVE operation:
UFFDIO_MOVE_MODE_DONTWAKE
Do not wake up the thread that waits for page-fault
resolution
UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES
Allow holes in the source virtual range that is being moved.
When not specified, the holes will result in ENOENT error.
When specified, the holes will be accounted as successfully
moved memory. This is mostly useful to move hugepage aligned
virtual regions without knowing if there are transparent
hugepages in the regions or not, but preventing the risk of
having to split the hugepage during the operation.
The move field is used by the kernel to return the number of
bytes that was actually moved, or an error (a negated errno-
style value). If the value returned in move doesn't match the
value that was specified in len, the operation fails with the
error EAGAIN. The move field is output-only; it is not read by
the UFFDIO_MOVE operation.
The operation may fail for various reasons. Usually, remapping of
pages that are not exclusive to the given process fail; once KSM
might deduplicate pages or fork() COW-shares pages during fork()
with child processes, they are no longer exclusive. Further, the
kernel might only perform lightweight checks for detecting whether
the pages are exclusive, and return -EBUSY in case that check fails.
To make the operation more likely to succeed, KSM should be
disabled, fork() should be avoided or MADV_DONTFORK should be
configured for the source VMA before fork().
This ioctl(2) operation returns 0 on success. In this case, the
entire area was moved. On error, -1 is returned and errno is
set to indicate the error. Possible errors include:
EAGAIN The number of bytes moved (i.e., the value returned in
the move field) does not equal the value that was
specified in the len field.
EINVAL Either dst or len was not a multiple of the system page
size, or the range specified by src and len or dst and len
was invalid.
EINVAL An invalid bit was specified in the mode field.
ENOENT
The source virtual memory range has unmapped holes and
UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES is not set.
EEXIST
The destination virtual memory range is fully or partially
mapped.
EBUSY
The pages in the source virtual memory range are either
pinned or not exclusive to the process. The kernel might
only perform lightweight checks for detecting whether the
pages are exclusive. To make the operation more likely to
succeed, KSM should be disabled, fork() should be avoided
or MADV_DONTFORK should be configured for the source virtual
memory area before fork().
ENOMEM Allocating memory needed for the operation failed.
ESRCH
The target process has exited at the time of a UFFDIO_MOVE
operation.
Link: https://lkml.kernel.org/r/20231206103702.3873743-3-surenb@google.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Both __block_write_full_folio() and block_read_full_folio() assumed that
block size <= PAGE_SIZE. Replace the shift with a divide, which is
probably cheaper than first calculating the shift. That lets us remove
block_size_bits() as these were the last callers.
Link: https://lkml.kernel.org/r/20231109210608.2252323-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When __block_write_begin_int() was converted to support folios, we did not
expect large folios to be passed to it. With the current work to support
large block size storage devices, this will no longer be true so change
the checks on 'from' and 'to' to be related to the size of the folio
instead of PAGE_SIZE. Also remove an assumption that the block size is
smaller than PAGE_SIZE.
Link: https://lkml.kernel.org/r/20231109210608.2252323-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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If i_blkbits is larger than PAGE_SHIFT, we shift by a negative number,
which is undefined. It is safe to shift the block left as a block device
must be smaller than MAX_LFS_FILESIZE, which is guaranteed to fit in
loff_t.
Link: https://lkml.kernel.org/r/20231109210608.2252323-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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While sector_t is always defined as a u64 today, that hasn't always been
the case and it might not always be the same size as loff_t in the future.
Link: https://lkml.kernel.org/r/20231109210608.2252323-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We must not shift by a negative number so work in terms of a byte offset
to avoid the awkward shift left-or-right-depending-on-sign option. This
means we need to use check_mul_overflow() to ensure that a large block
number does not result in a wrap.
Link: https://lkml.kernel.org/r/20231109210608.2252323-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
[nathan@kernel.org: add cast in grow_buffers() to avoid a multiplication libcall]
Link: https://lkml.kernel.org/r/20231128-avoid-muloti4-grow_buffers-v1-1-bc3d0f0ec483@kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The calculation of block from index doesn't work for devices with a block
size larger than PAGE_SIZE as we end up shifting by a negative number.
Instead, calculate the number of the first block from the folio's position
in the block device. We no longer need to pass sizebits to
grow_dev_folio().
Link: https://lkml.kernel.org/r/20231109210608.2252323-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "More buffer_head cleanups", v2.
The first patch is a left-over from last cycle. The rest fix "obvious"
block size > PAGE_SIZE problems. I haven't tested with a large block size
setup (but I have done an ext4 xfstests run).
This patch (of 7):
Rename grow_dev_page() to grow_dev_folio() and make it return a bool.
Document what that bool means; it's more subtle than it first appears.
Also rename the 'failed' label to 'unlock' beacuse it's not exactly
'failed'. It just hasn't succeeded.
Link: https://lkml.kernel.org/r/20231109210608.2252323-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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parse_server_interfaces should be in complete charge of maintaining
the iface_list linked list. Today, iface entries are removed
from the list only when the last refcount is dropped.
i.e. in release_iface. However, this can result in undercounting
of refcount if the server stops advertising interfaces (which
Azure SMB server does).
This change puts parse_server_interfaces in full charge of
maintaining the iface_list. So if an empty list is returned
by the server, the entries in the list will immediately be
removed. This way, a following call to the same function will
not find entries in the list.
Fixes: aa45dadd34e4 ("cifs: change iface_list from array to sorted linked list")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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cifs_chan_is_iface_active checks the channels of a session to see
if the associated iface is active. This should always happen
with chan_lock held. However, these two callers of this function
were missing this locking.
This change makes sure the function calls are protected with
proper locking.
Fixes: b54034a73baf ("cifs: during reconnect, update interface if necessary")
Fixes: fa1d0508bdd4 ("cifs: account for primary channel in the interface list")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Once the server disables multichannel for an active multichannel
session, on the following reconnect, the client would reduce
the number of channels to 1. However, it could be the case that
the tree connect was active on one of these disabled channels.
This results in an unrecoverable state.
This change fixes that by making sure that whenever a channel
is being terminated, the session and tcon are marked for
reconnect too. This could mean a few redundant tree connect
calls to the server, but considering that this is not a frequent
event, we should be okay.
Fixes: ee1d21794e55 ("cifs: handle when server stops supporting multichannel")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Instead of tracing the address of the recovery handler, use the name
in the defer op, similar to other defer ops related tracepoints.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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dfp will be freed by ->recover_work and thus the tracepoint in case
of an error can lead to a use after free.
Store the defer ops in a local variable to avoid that.
Fixes: 7f2f7531e0d4 ("xfs: store an ops pointer in struct xfs_defer_pending")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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asserts
Since commit deed9512872d ("xfs: Check for -ENOATTR or -EEXIST"), the
high-level attr code does a lookup for any attr we're trying to set,
and does the checks to handle the create vs replace cases, which thus
never hit the low-level attr code.
Turn the checks in xfs_attr_shortform_addname as they must never trip.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Remove the last two users of the typedef.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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sparse complains about struct xfs_attr_shortform because it embeds a
structure with a variable sized array in a variable sized array.
Given that xfs_attr_shortform is not a very useful structure, and the
dir2 equivalent has been removed a long time ago, remove it as well.
Provide a xfs_attr_sf_firstentry helper that returns the first
xfs_attr_sf_entry behind a xfs_attr_sf_hdr to replace the structure
dereference.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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xfs_attr_shortform_getvalue duplicates the logic in xfs_attr_sf_findname.
Use the helper instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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xfs_attr_shortform_lookup is only used by xfs_attr_shortform_addname,
which is much better served by calling xfs_attr_sf_findname. Switch
it over and remove xfs_attr_shortform_lookup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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xfs_attr_sf_findname has the simple job of finding a xfs_attr_sf_entry in
the attr fork, but the convoluted calling convention obfuscates that.
Return the found entry as the return value instead of an pointer
argument, as the -ENOATTR/-EEXIST can be trivally derived from that, and
remove the basep argument, as it is equivalent of the offset of sfe in
the data for if an sfe was found, or an offset of totsize if not was
found. To simplify the totsize computation add a xfs_attr_sf_endptr
helper that returns the imaginative xfs_attr_sf_entry at the end of
the current attrs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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trace_xfs_attr_sf_lookup is currently only called by
xfs_attr_shortform_lookup, which despit it's name is a simple helper for
xfs_attr_shortform_addname, which has it's own tracing. Move the
callsite to xfs_attr_shortform_getvalue, which is the closest thing to
a high level lookup we have for the Linux xattr API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Many of the xfs_idata_realloc callers need to set a local pointer to the
just reallocated if_data memory. Return the pointer to simplify them a
bit and use the opportunity to re-use krealloc for freeing if_data if the
size hits 0.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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The xfs_ifork structure currently has a union of the if_root void pointer
and the if_data char pointer. In either case it is an opaque pointer
that depends on the fork format. Replace the union with a single if_data
void pointer as that is what almost all callers want. Only the symlink
NULL termination code in xfs_init_local_fork actually needs a new local
variable now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Pull ksmbd server fix from Steve French:
- address possible slab out of bounds in parsing of open requests
* tag '6.7rc7-smb3-srv-fix' of git://git.samba.org/ksmbd:
ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()
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Pull bcachefs fixes from Kent Overstreet:
"Just a few fixes: besides a few one liners, we have a fix for
snapshots + compression where the extent update path didn't account
for the fact that with snapshots, we might split an existing extent
into three, not just two; and a small fixup for promotes which were
broken by the recent changes in the data update path to correctly take
into account device durability"
* tag 'bcachefs-2023-12-27' of https://evilpiepirate.org/git/bcachefs:
bcachefs: Fix promotes
bcachefs: Fix leakage of internal error code
bcachefs: Fix insufficient disk reservation with compression + snapshots
bcachefs: fix BCH_FSCK_ERR enum
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This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove empty sentinel from coda_table
Signed-off-by: Joel Granados <j.granados@samsung.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove sentinel elements ctl_table struct. Special attention was placed in
making sure that an empty directory for fs/verity was created when
CONFIG_FS_VERITY_BUILTIN_SIGNATURES is not defined. In this case we use the
register sysctl call that expects a size.
Signed-off-by: Joel Granados <j.granados@samsung.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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This commit comes at the tail end of a greater effort to remove the empty
elements at the end of the ctl_table arrays (sentinels) which will reduce the
overall build time size of the kernel and run time memory bloat by ~64 bytes
per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove sentinel from cachefiles_sysctls
Signed-off-by: Joel Granados <j.granados@samsung.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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When registering tables to the sysctl subsystem there is a check to see
if header is a permanently empty directory (used for mounts). This check
evaluates the first element of the ctl_table. This results in an out of
bounds evaluation when registering empty directories.
The function register_sysctl_mount_point now passes a ctl_table of size
1 instead of size 0. It now relies solely on the type to identify
a permanently empty register.
Make sure that the ctl_table has at least one element before testing for
permanent emptiness.
Signed-off-by: Joel Granados <j.granados@samsung.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202311201431.57aae8f3-oliver.sang@intel.com
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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The cpu_key was not initialized in reiserfs_delete_solid_item(), which triggered
this issue.
Reported-and-tested-by: <syzbot+b3b14fb9f8a14c5d0267@syzkaller.appspotmail.com>
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Link: https://lore.kernel.org/r/tencent_9EA7E746DE92DBC66049A62EDF6ED64CA706@qq.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use netfslib's read and write iteration helpers, allowing netfslib to take
over the management of the page cache for 9p files and to manage local disk
caching. In particular, this eliminates write_begin, write_end, writepage
and all mentions of struct page and struct folio from 9p.
Note that netfslib now offers the possibility of write-through caching if
that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in
v9inode->netfs.flags in v9fs_set_netfs_context().
Note also this is untested as I can't get ganesha.nfsd to correctly parse
the config to turn on 9p support.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: v9fs@lists.linux.dev
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
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Make afs use the netfs write helpers.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Export the netfs_sreq tracepoint so that it can be called directly from
client filesystems/cache backend modules.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Track the file position above which the server is not expected to have any
data (the "zero point") and preemptively assume that we can satisfy
requests by filling them with zeroes locally rather than attempting to
download them if they're over that line - even if we've written data back
to the server. Assume that any data that was written back above that
position is held in the local cache. Note that we have to split requests
that straddle the line.
Make use of this to optimise away some reads from the server. We need to
set the zero point in the following circumstances:
(1) When we see an extant remote inode and have no cache for it, we set
the zero_point to i_size.
(2) On local inode creation, we set zero_point to 0.
(3) On local truncation down, we reduce zero_point to the new i_size if
the new i_size is lower.
(4) On local truncation up, we don't change zero_point.
(5) On local modification, we don't change zero_point.
(6) On remote invalidation, we set zero_point to the new i_size.
(7) If stored data is discarded from the pagecache or culled from fscache,
we must set zero_point above that if the data also got written to the
server.
(8) If dirty data is written back to the server, but not fscache, we must
set zero_point above that.
(9) If a direct I/O write is made, set zero_point above that.
Assuming the above, any read from the server at or above the zero_point
position will return all zeroes.
The zero_point value can be stored in the cache, provided the above rules
are applied to it by any code that culls part of the local cache.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Provide a flag whereby a filesystem may request that cifs_perform_write()
perform write-through caching. This involves putting pages directly into
writeback rather than dirty and attaching them to a write operation as we
go.
Further, the writes being made are limited to the byte range being written
rather than whole folios being written. This can be used by cifs, for
example, to deal with strict byte-range locking.
This can't be used with content encryption as that may require expansion of
the write RPC beyond the write being made.
This doesn't affect writes via mmap - those are written back in the normal
way; similarly failed writethrough writes are marked dirty and left to
writeback to retry. Another option would be to simply invalidate them, but
the contents can be simultaneously accessed by read() and through mmap.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Provide a launder_folio implementation for netfslib.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Provide an implementation of writepages for network filesystems to delegate
to.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Make netfslib pass the maximum length to the ->prepare_write() op to tell
the cache how much it can expand the length of a write to. This allows a
write to the server at the end of a file to be limited to a few bytes
whilst writing an entire block to the cache (something required by direct
I/O).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Provide a top-level-ish function that can be pointed to directly by
->read_iter file op.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Provide an entry point to delegate a filesystem's ->page_mkwrite() to.
This checks for conflicting writes, then attached any netfs-specific group
marking (e.g. ceph snap) to the page to be considered dirty.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Institute a netfs write helper, netfs_file_write_iter(), to be pointed at
by the network filesystem ->write_iter() call. Make it handled buffered
writes by calling the previously defined netfs_perform_write() to copy the
source data into the pagecache.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Implement support for unbuffered writes and direct I/O writes. If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary. DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.
Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing. The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.
The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method. Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.
Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined. As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.
In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Allocate a multipage folio when copying data into the pagecache if possible
if there's sufficient data to warrant it.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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netfs_read_folio() needs to handle partially-valid pages that are marked
dirty, but not uptodate in the event that someone tries to read a page was
used to cache data by a streaming write.
In such a case, make netfs_read_folio() set up a bvec iterator that points
to the parts of the folio that need filling and to a sink page for the data
that should be discarded and use that instead of i_pages as the iterator to
be written to.
This requires netfs_rreq_unlock_folios() to convert the page into a normal
dirty uptodate page, getting rid of the partial write record and bumping
the group pointer over to folio->private.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Provide a netfs write helper, netfs_perform_write() to buffer data to be
written in the pagecache and mark the modified folios dirty.
It will perform "streaming writes" for folios that aren't currently
resident, if possible, storing data in partially modified folios that are
marked dirty, but not uptodate. It will also tag pages as belonging to
fs-specific write groups if so directed by the filesystem.
This is derived from generic_perform_write(), but doesn't use
->write_begin() and ->write_end(), having that logic rolled in instead.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Dispatch one or more write reqeusts to process a writeback slice, where a
slice is tailored more to logical block divisions within the file (such as
crypto blocks, an object layout or cache granules) than the protocol RPC
maximum capacity.
The dispatch doesn't happen until throttling allows, at which point the
entire writeback slice is processed and queued. A slice may be written to
multiple destinations (one or more servers and the local cache) and the
writes to each destination might be split up along different lines.
The writeback slice holds the required folios pinned. An iov_iter is
provided in netfs_write_request that describes the buffer to be used. This
may be part of the pagecache, may have auxiliary padding pages attached or
may be a bounce buffer resulting from crypto or compression. Consequently,
the filesystem must not twiddle the folio markings directly.
The following API is available to the filesystem:
(1) The ->create_write_requests() method is called to ask the filesystem
to create the requests it needs. This is passed the writeback slice
to be processed.
(2) The filesystem should then call netfs_create_write_request() to create
the requests it needs.
(3) Once a request is initialised, netfs_queue_write_request() can be
called to dispatch it asynchronously, if not completed immediately.
(4) netfs_write_request_completed() should be called to note the
completion of a request.
(5) netfs_get_write_request() and netfs_put_write_request() are provided
to refcount a request. These take constants from the netfs_wreq_trace
enum for logging into ftrace.
(6) The ->free_write_request is method is called to ask the filesystem to
clean up a request.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Prepare to use folio->private to hold information write grouping and
streaming write. These are implemented in the same commit as they both
make use of folio->private and will be both checked at the same time in
several places.
"Write grouping" involves ordering the writeback of groups of writes, such
as is needed for ceph snaps. A group is represented by a
filesystem-supplied object which must contain a netfs_group struct. This
contains just a refcount and a pointer to a destructor.
"Streaming write" is the storage of data in folios that are marked dirty,
but not uptodate, to avoid unnecessary reads of data. This is represented
by a netfs_folio struct. This contains the offset and length of the
modified region plus the otherwise displaced write grouping pointer.
The way folio->private is multiplexed is:
(1) If private is NULL then neither is in operation on a dirty folio.
(2) If private is set, with bit 0 clear, then this points to a group.
(3) If private is set, with bit 0 set, then this points to a netfs_folio
struct (with bit 0 AND'ed out).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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Make the refcounting of netfs_begin_read() easier to use by not eating the
caller's ref on the netfs_io_request it's given. This makes it easier to
use when we need to look in the request struct after.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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