kernel.git/fs/iomap, branch linux-5.16.y

iomap: iomap_read_inline_data cleanup

2021-11-24T18:15:47Z

Change iomap_read_inline_data to return 0 or an error code; this simplifies the callers. Add a description. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig [djwong: document the return value of iomap_read_inline_data explicitly] Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

iomap: Fix inline extent handling in iomap_readpage

2021-11-22T00:28:07Z

Before commit 740499c78408 ("iomap: fix the iomap_readpage_actor return value for inline data"), when hitting an IOMAP_INLINE extent, iomap_readpage_actor would report having read the entire page. Since then, it only reports having read the inline data (iomap->length). This will force iomap_readpage into another iteration, and the filesystem will report an unaligned hole after the IOMAP_INLINE extent. But iomap_readpage_actor (now iomap_readpage_iter) isn't prepared to deal with unaligned extents, it will get things wrong on filesystems with a block size smaller than the page size, and we'll eventually run into the following warning in iomap_iter_advance: WARN_ON_ONCE(iter->processed > iomap_length(iter)); Fix that by changing iomap_readpage_iter to return 0 when hitting an inline extent; this will cause iomap_iter to stop immediately. To fix readahead as well, change iomap_readahead_iter to pass on iomap_readpage_iter return values less than or equal to zero. Fixes: 740499c78408 ("iomap: fix the iomap_readpage_actor return value for inline data") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

2021-11-02T19:25:03Z

Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher: "Functions gfs2_file_read_iter and gfs2_file_write_iter are both accessing the user buffer to write to or read from while holding the inode glock. In the most basic deadlock scenario, that buffer will not be resident and it will be mapped to the same file. Accessing the buffer will trigger a page fault, and gfs2 will deadlock trying to take the same inode glock again while trying to handle that fault. Fix that and similar, more complex scenarios by disabling page faults while accessing user buffers. To make this work, introduce a small amount of new infrastructure and fix some bugs that didn't trigger so far, with page faults enabled" * tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fix mmap + page fault deadlocks for direct I/O iov_iter: Introduce nofault flag to disable page faults gup: Introduce FOLL_NOFAULT flag to disable page faults iomap: Add done_before argument to iomap_dio_rw iomap: Support partial direct I/O on user copy failures iomap: Fix iomap_dio_rw return value for user copies gfs2: Fix mmap + page fault deadlocks for buffered I/O gfs2: Eliminate ip->i_gh gfs2: Move the inode glock locking to gfs2_file_buffered_write gfs2: Introduce flag for glock holder auto-demotion gfs2: Clean up function may_grant gfs2: Add wrapper for iomap_file_buffered_write iov_iter: Introduce fault_in_iov_iter_writeable iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} powerpc/kvm: Fix kvm_use_magic_page iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value

fs: get rid of the res2 iocb->ki_complete argument

2021-10-25T16:36:24Z

The second argument was only used by the USB gadget code, yet everyone pays the overhead of passing a zero to be passed into aio, where it ends up being part of the aio res2 value. Now that everybody is passing in zero, kill off the extra argument. Reviewed-by: Darrick J. Wong Signed-off-by: Jens Axboe

iomap: Add done_before argument to iomap_dio_rw

2021-10-24T13:26:05Z

Add a done_before argument to iomap_dio_rw that indicates how much of the request has already been transferred. When the request succeeds, we report that done_before additional bytes were tranferred. This is useful for finishing a request asynchronously when part of the request has already been completed synchronously. We'll use that to allow iomap_dio_rw to be used with page faults disabled: when a page fault occurs while submitting a request, we synchronously complete the part of the request that has already been submitted. The caller can then take care of the page fault and call iomap_dio_rw again for the rest of the request, passing in the number of bytes already tranferred. Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong

iomap: Support partial direct I/O on user copy failures

2021-10-24T13:26:05Z

In iomap_dio_rw, when iomap_apply returns an -EFAULT error and the IOMAP_DIO_PARTIAL flag is set, complete the request synchronously and return a partial result. This allows the caller to deal with the page fault and retry the remainder of the request. Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong

iomap: Fix iomap_dio_rw return value for user copies

2021-10-24T13:26:05Z

When a user copy fails in one of the helpers of iomap_dio_rw, fail with -EFAULT instead of returning 0. This matches what iomap_dio_bio_actor returns when it gets an -EFAULT from bio_iov_iter_get_pages. With these changes, iomap_dio_actor now consistently fails with -EFAULT when a user page cannot be faulted in. Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig

block: add a struct io_comp_batch argument to fops->iopoll()

2021-10-18T20:40:40Z

struct io_comp_batch contains a list head and a completion handler, which will allow completions to more effciently completed batches of IO. For now, no functional changes in this patch, we just define the io_comp_batch structure and add the argument to the file_operations iopoll handler. Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable

2021-10-18T14:35:06Z

Turn iov_iter_fault_in_readable into a function that returns the number of bytes not faulted in, similar to copy_to_user, instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in as well as new users that are happy if any pages can be faulted in. Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make sure this change doesn't silently break things. Signed-off-by: Andreas Gruenbacher

block: switch polling to be bio based

2021-10-18T12:17:36Z

Replace the blk_poll interface that requires the caller to keep a queue and cookie from the submissions with polling based on the bio. Polling for the bio itself leads to a few advantages: - the cookie construction can made entirely private in blk-mq.c - the caller does not need to remember the request_queue and cookie separately and thus sidesteps their lifetime issues - keeping the device and the cookie inside the bio allows to trivially support polling BIOs remapping by stacking drivers - a lot of code to propagate the cookie back up the submission path can be removed entirely. Signed-off-by: Christoph Hellwig Tested-by: Mark Wunderlich Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de Signed-off-by: Jens Axboe