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5bd2c0650a
We will be shortly removing the vm_flags_t field from vm_area_desc so we need to update all mmap_prepare users to only use the dessc->vma_flags field. This patch achieves that and makes all ancillary changes required to make this possible. This lays the groundwork for future work to eliminate the use of vm_flags_t in vm_area_desc altogether and more broadly throughout the kernel. While we're here, we take the opportunity to replace VM_REMAP_FLAGS with VMA_REMAP_FLAGS, the vma_flags_t equivalent. No functional changes intended. Link: https://lkml.kernel.org/r/fb1f55323799f09fe6a36865b31550c9ec67c225.1769097829.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Damien Le Moal <dlemoal@kernel.org> [zonefs] Acked-by: "Darrick J. Wong" <djwong@kernel.org> Acked-by: Pedro Falcato <pfalcato@suse.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Yury Norov <ynorov@nvidia.com> Cc: Chris Mason <clm@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
85 lines
2.3 KiB
C
85 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* NOMMU mmap support for RomFS on MTD devices
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*
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* Copyright © 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <linux/mm.h>
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#include <linux/mtd/super.h>
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#include "internal.h"
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/*
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* try to determine where a shared mapping can be made
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* - only supported for NOMMU at the moment (MMU can't doesn't copy private
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* mappings)
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* - attempts to map through to the underlying MTD device
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*/
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static unsigned long romfs_get_unmapped_area(struct file *file,
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unsigned long addr,
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unsigned long len,
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unsigned long pgoff,
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unsigned long flags)
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{
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struct inode *inode = file->f_mapping->host;
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struct mtd_info *mtd = inode->i_sb->s_mtd;
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unsigned long isize, offset, maxpages, lpages;
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int ret;
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if (!mtd)
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return (unsigned long) -ENOSYS;
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/* the mapping mustn't extend beyond the EOF */
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lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
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isize = i_size_read(inode);
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offset = pgoff << PAGE_SHIFT;
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maxpages = (isize + PAGE_SIZE - 1) >> PAGE_SHIFT;
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if ((pgoff >= maxpages) || (maxpages - pgoff < lpages))
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return (unsigned long) -EINVAL;
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if (addr != 0)
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return (unsigned long) -EINVAL;
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if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
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return (unsigned long) -EINVAL;
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offset += ROMFS_I(inode)->i_dataoffset;
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if (offset >= mtd->size)
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return (unsigned long) -EINVAL;
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/* the mapping mustn't extend beyond the EOF */
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if ((offset + len) > mtd->size)
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len = mtd->size - offset;
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ret = mtd_get_unmapped_area(mtd, len, offset, flags);
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if (ret == -EOPNOTSUPP)
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ret = -ENOSYS;
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return (unsigned long) ret;
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}
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/*
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* permit a R/O mapping to be made directly through onto an MTD device if
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* possible
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*/
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static int romfs_mmap_prepare(struct vm_area_desc *desc)
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{
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return is_nommu_shared_vma_flags(&desc->vma_flags) ? 0 : -ENOSYS;
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}
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static unsigned romfs_mmap_capabilities(struct file *file)
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{
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struct mtd_info *mtd = file_inode(file)->i_sb->s_mtd;
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if (!mtd)
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return NOMMU_MAP_COPY;
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return mtd_mmap_capabilities(mtd);
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}
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const struct file_operations romfs_ro_fops = {
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.llseek = generic_file_llseek,
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.read_iter = generic_file_read_iter,
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.splice_read = filemap_splice_read,
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.mmap_prepare = romfs_mmap_prepare,
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.get_unmapped_area = romfs_get_unmapped_area,
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.mmap_capabilities = romfs_mmap_capabilities,
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};
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