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path: root/fs/romfs/mmap-nommu.c
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2023-05-24splice: Use filemap_splice_read() instead of generic_file_splice_read()David Howells
Replace pointers to generic_file_splice_read() with calls to filemap_splice_read(). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: David Hildenbrand <david@redhat.com> cc: John Hubbard <jhubbard@nvidia.com> cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20230522135018.2742245-29-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-18mm/nommu: factor out check for NOMMU shared mappings into ↵David Hildenbrand
is_nommu_shared_mapping() Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings". Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings. This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is actually means. Let's first get the weird case out of the way and not use VM_MAYSHARE in MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead. This patch (of 3): We want to stop using VM_MAYSHARE in private mappings to pave the way for clarifying the semantics of VM_MAYSHARE vs. VM_SHARED and reduce the confusion. While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED, !CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings that are an effective overlay of a file mapping. Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into is_nommu_shared_mapping() first. Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well (unless there is a serious BUG). So there is not need to test for VM_SHARED manually. No functional change intended. Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-11make new_sync_{read,write}() staticAl Viro
All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-20fs: introduce f_op->mmap_capabilities for nommu mmap supportChristoph Hellwig
Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-06switch simple generic_file_aio_read() users to ->read_iter()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29romfs: fix nommu map length to keep inside filesystemGreg Ungerer
Checks introduced in commit 4991e7251 ("romfs: do not use mtd->get_unmapped_area directly") re-introduce problems fixed in the earlier commit 2b4b2482e ("romfs: fix romfs_get_unmapped_area() argument check"). If a flat binary app is located at the end of a romfs, its page aligned length may be outside of the romfs filesystem. The flat binary loader, via nommu do_mmap_pgoff(), page aligns the length it is mmaping. So simple offset+size checks will fail - returning EINVAL. We can truncate the length to keep it inside the romfs filesystem, and that also keeps the call to mtd_get_unmapped_area() happy. Are there any side effects to truncating the size here though? Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2012-01-09romfs: do not use mtd->get_unmapped_area directlyArtem Bityutskiy
Remove direct usage of mtd->get_unmapped_area. Instead, just call 'mtd_get_unmapped_area()' which will return -EOPNOTSUPP if the function is not implemented, and then test for this code. We also translate -EOPNOTSUPP to -ENOSYS because this return code is probably part of the kernel ABI which we do not want to break. Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-01-09mtd: introduce mtd_get_unmapped_area interfaceArtem Bityutskiy
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2011-06-27romfs: fix romfs_get_unmapped_area() argument checkBob Liu
romfs_get_unmapped_area() checks argument `len' without considering PAGE_ALIGN which will cause do_mmap_pgoff() return -EINVAL error after commit f67d9b1576c ("nommu: add page_align to mmap"). Fix the check by changing it in same way ramfs_nommu_get_unmapped_area() was changed in ramfs/file-nommu.c. Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: Greg Ungerer <gerg@snapgear.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-24NOMMU: Make it possible for RomFS to use MTD devices directlyDavid Howells
Change RomFS so that it can use MTD devices directly - without the intercession of the block layer - as well as using block devices. This permits RomFS: (1) to use the MTD direct mapping facility available under NOMMU conditions if the underlying device is directly accessible by the CPU (including XIP); (2) and thus to be used when the block layer is disabled. RomFS can be configured with support just for MTD devices, just for Block devices or for both. If RomFS is configured for both, then it will treat mtdblock device files as MTD backing stores, not block layer backing stores. I tested this using a CONFIG_MMU=n CONFIG_BLOCK=n kernel running on my FRV board with a RomFS image installed on the mtdram test device. I see my test program being run XIP: # cat /proc/maps ... c0c000b0-c0c01f8c r-xs 00000000 1f:00 144 /mnt/doshm ... GDB on the kernel can be used to show that these addresses are within the set-aside RAM space. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Bernd Schmidt <bernd.schmidt@analog.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>