Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

these were already checked in check_subvol()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

check for inodes with a nonzero bi_parent_subvol field that aren't
actually subvolume roots
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

check that if an inode has a backpointer, the dirent it points to points
back to it.

We do this in check_dirent_inode_dirent(), but only for inodes that have
dirents that point to them - we also have to do the check starting from
the inode to catch inodes that don't have dirents that point to them.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Subvolumes and subvolume root inodes point to each other: this verifies
the subvolume -> inode -> subvolme path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This converts -EIOs related to btree node errors to private error codes,
which will help with some ongoing debugging by giving us better error
messages.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Add a flush op, to return the exit code via close().

Also update bcachefs usage to use this to return fsck exit codes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Fixes: https://lore.kernel.org/linux-bcachefs/202402131603.E953E2CF@keescook/T/#u
Reported-by: coverity scan
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Make it so that a thread_with_stdio user can handle ioctls against the
file descriptor.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Create an ops structure so we can add more file-based functionality in
the next few patches.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Experimentally fix some problems with stdio_redirect_vprintf by creating
a MOO variant with which we can experiment.  We can't do a GFP_KERNEL
allocation while holding the spinlock, and I don't like how the printf
function can silently truncate the output if memory allocation fails.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Create a new run_thread_with_stdout function that opens a file in
O_RDONLY mode so that the kernel can write things to userspace but
userspace cannot write to the kernel.  This will be used to convey xfs
health event information to userspace.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

needed for thread_with_file; also rare but not unheard of to need this
in module code, when blocking on user input.

one workaround used by some code is wait_event_interruptible() - but
that can be buggy if the outer context isn't expecting unwinding.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: fuyuanli <fuyuanli@didiglobal.com>

This fixes stdio_redirect_read() getting stuck, not noticing that the
pipe has been closed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

This fixes a bug where we'd return data without waiting for a newline,
if data was present but a newline was not.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Move the cleanup code to a wrapper function, where we can call it after
the thread_with_stdio fn exits.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

 - eliminate the dependency on printbufs, so that we can lift
   thread_with_file for use in xfs
 - add a nonblocking parameter to stdio_redirect_printf(), and either
   block if the buffer is full or drop it on the floor - don't buffer
   infinitely
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

The output buffer lock has to be a spinlock so that we can write to it
from interrupt context, so we can't use a direct copy_to_user; this
switches thread_with_file_read() to use fault_in_writeable() and
copy_to_user_nofault(), similar to how thread_with_file_write() works.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Add mempool_init_kvmalloc_pool() and mempool_create_kvmalloc_pool(),
which wrap kvmalloc() instead of kmalloc() - kmalloc() with a vmalloc()
fallback.

This is part of a bcachefs cleanup - dropping an internal kvpmalloc()
helper (which predates kvmalloc()) along with mempool helpers; this
replaces the bcachefs-private kvpmalloc_pool.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: linux-mm@kvack.org

When a dirent points to a missing inode, we really should print out the
dirent.

This requires quite a bit of refactoring, but there's some other
benefits: we now do the entire looup (dirent and inode) in a single
btree transaction, and copy to the VFS inode with btree locks still
held, like the create path.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Introduce PF_MEMALLOC_* equivalents of some GFP_ flags:

PF_MEMALLOC_NORECLAIM	-> GFP_NOWAIT
PF_MEMALLOC_NOWARN	-> __GFP_NOWARN

Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: linux-mm@kvack.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Our proliferation of memalloc_*_{save,restore} APIs is getting a bit
silly, this adds a generic version and converts the existing
save/restore functions to wrappers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: linux-mm@kvack.org
Acked-by: Vlastimil Babka <vbabka@suse.cz>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Going to be adding more code here for checking subvol structure.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Repurposing standard error codes in bcachefs code is banned in new code,
and we need to get rid of the remaining ones - private error codes give
us much better error messages.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

WQ_UNBOUND with max_active 1 means ordered workqueue, but we don't
actually need or want ordered semantics - and probably want a higher
concurrency limit anyways.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Need to fix this oversight for the new FS_IOC_(GET|SET)UUID ioctls.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

switch the statfs code from something horrible and open coded to the
more standard uuid_to_fsid()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Files within a subvolume cannot be renamed into another subvolume, but
subvolumes themselves were intended to be.

This implements subvolume renaming - we need to ensure that there's only
a single dirent that points to a subvolume key (not multiple versions in
different snapshots), and we need to ensure that dirent.d_parent_subol
and inode.bi_parent_subvol are updated.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

btree_and_journal_iter is old code that we want to get rid of, but we're
not ready to yet.

lack of btree node prefetching is, it turns out, a real performance
issue for fsck on spinning rust, so - add it.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

we now always have a btree_trans when using a btree_and_journal_iter;
prep work for adding prefetching to btree_and_journal_iter
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Recently a severe performance regression was discovered, which bisected
to

  a6548c8b bcachefs: Avoid flushing the journal in the discard path

It turns out the old behaviour, which issued excessive journal flushes,
worked around a performance issue where queueing delays would cause the
journal to not be able to write quickly enough and stall.

The journal flushes masked the issue because they periodically flushed
the device write cache, reducing write latency for non flushes.

This patch reworks the journalling code to allow more than one
(non-flush) write to be in flight at a time. With this patch, doing 4k
random writes and an iodepth of 128, we are now able to hit 560k iops to
a Samsung 970 EVO Plus - previously, we were stuck in the ~200k range.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>