kernel/linux.git/fs/affs, branch v6.1.168

affs: don't write overlarge OFS data block size fields

2025-04-10T12:33:38+00:00

[ Upstream commit 011ea742a25a77bac3d995f457886a67d178c6f0 ] If a data sector on an OFS floppy contains a value > 0x1e8 (the largest amount of data that fits in the sector after its header), then an Amiga reading the file can return corrupt data, by taking the overlarge size at its word and reading past the end of the buffer it read the disk sector into! The cause: when affs_write_end_ofs() writes data to an OFS filesystem, the new size field for a data block was computed by adding the amount of data currently being written (into the block) to the existing value of the size field. This is correct if you're extending the file at the end, but if you seek backwards in the file and overwrite _existing_ data, it can lead to the size field being larger than the maximum legal value. This commit changes the calculation so that it sets the size field to the max of its previous size and the position within the block that we just wrote up to. Signed-off-by: Simon Tatham Signed-off-by: David Sterba Signed-off-by: Sasha Levin

affs: generate OFS sequence numbers starting at 1

2025-04-10T12:33:38+00:00

[ Upstream commit e4cf8ec4de4e13f156c1d61977d282d90c221085 ] If I write a file to an OFS floppy image, and try to read it back on an emulated Amiga running Workbench 1.3, the Amiga reports a disk error trying to read the file. (That is, it's unable to read it _at all_, even to copy it to the NIL: device. It isn't a matter of getting the wrong data and being unable to parse the file format.) This is because the 'sequence number' field in the OFS data block header is supposed to be based at 1, but affs writes it based at 0. All three locations changed by this patch were setting the sequence number to a variable 'bidx' which was previously obtained by dividing a file position by bsize, so bidx will naturally use 0 for the first block. Therefore all three should add 1 to that value before writing it into the sequence number field. With this change, the Amiga successfully reads the file. For data block reference: https://wiki.osdev.org/FFS_(Amiga) Signed-off-by: Simon Tatham Signed-off-by: David Sterba Signed-off-by: Sasha Levin

affs: initialize fsdata in affs_truncate()

2023-02-01T07:34:08+00:00

[ Upstream commit eef034ac6690118c88f357b00e2b3239c9d8575d ] When aops->write_begin() does not initialize fsdata, KMSAN may report an error passing the latter to aops->write_end(). Fix this by unconditionally initializing fsdata. Fixes: f2b6a16eb8f5 ("fs: affs convert to new aops") Suggested-by: Eric Biggers Signed-off-by: Alexander Potapenko Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

affs: move from strlcpy with unused retval to strscpy

2022-08-19T11:03:10+00:00

Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang Reviewed-by: David Sterba Signed-off-by: David Sterba

affs: use memcpy_to_page and remove replace kmap_atomic()

2022-08-01T17:53:31+00:00

The use of kmap() is being deprecated in favor of kmap_local_page() where it is feasible. For kmap around a memcpy there's a convenience helper memcpy_to_page that also makes the flush_dcache_page() redundant. CC: Fabio M. De Francesco Reviewed-by: Ira Weiny Signed-off-by: David Sterba

affs: Convert affs to read_folio

2022-05-09T20:21:44+00:00

This is a "weak" conversion which converts straight back to using pages. A full conversion should be performed at some point, hopefully by someone familiar with the filesystem. Signed-off-by: Matthew Wilcox (Oracle)

fs: Convert block_read_full_page() to block_read_full_folio()

2022-05-09T20:21:44+00:00

This function is NOT converted to handle large folios, so include an assert that the filesystem isn't passing one in. Otherwise, use the folio functions instead of the page functions, where they exist. Convert all filesystems which use block_read_full_page(). Signed-off-by: Matthew Wilcox (Oracle)

fs: Remove flags parameter from aops->write_begin

2022-05-08T18:28:19+00:00

There are no more aop flags left, so remove the parameter. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig

fs: Remove aop flags parameter from grab_cache_page_write_begin()

2022-05-08T18:28:19+00:00

There are no more aop flags left, so remove the parameter. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig

fs: Remove aop flags parameter from cont_write_begin()

2022-05-08T18:28:19+00:00

There are no more aop flags left, so remove the parameter. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig