/* * mm/fadvise.c * * Copyright (C) 2002, Linus Torvalds * * 11Jan2003 Andrew Morton * Initial version. */ #include #include #include #include #include #include #include #include #include #include #include #include /* * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could * deactivate the pages and clear PG_Referenced. */ SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice) { struct fd f = fdget(fd); struct inode *inode; struct address_space *mapping; struct backing_dev_info *bdi; loff_t endbyte; /* inclusive */ pgoff_t start_index; pgoff_t end_index; unsigned long nrpages; int ret = 0; if (!f.file) return -EBADF; inode = file_inode(f.file); if (S_ISFIFO(inode->i_mode)) { ret = -ESPIPE; goto out; } mapping = f.file->f_mapping; if (!mapping || len < 0) { ret = -EINVAL; goto out; } if (IS_DAX(inode)) { switch (advice) { case POSIX_FADV_NORMAL: case POSIX_FADV_RANDOM: case POSIX_FADV_SEQUENTIAL: case POSIX_FADV_WILLNEED: case POSIX_FADV_NOREUSE: case POSIX_FADV_DONTNEED: /* no bad return value, but ignore advice */ break; default: ret = -EINVAL; } goto out; } /* Careful about overflows. Len == 0 means "as much as possible" */ endbyte = offset + len; if (!len || endbyte < len) endbyte = -1; else endbyte--; /* inclusive */ bdi = inode_to_bdi(mapping->host); switch (advice) { case POSIX_FADV_NORMAL: f.file->f_ra.ra_pages = bdi->ra_pages; spin_lock(&f.file->f_lock); f.file->f_mode &= ~FMODE_RANDOM; spin_unlock(&f.file->f_lock); break; case POSIX_FADV_RANDOM: spin_lock(&f.file->f_lock); f.file->f_mode |= FMODE_RANDOM; spin_unlock(&f.file->f_lock); break; case POSIX_FADV_SEQUENTIAL: f.file->f_ra.ra_pages = bdi->ra_pages * 2; spin_lock(&f.file->f_lock); f.file->f_mode &= ~FMODE_RANDOM; spin_unlock(&f.file->f_lock); break; case POSIX_FADV_WILLNEED: /* First and last PARTIAL page! */ start_index = offset >> PAGE_SHIFT; end_index = endbyte >> PAGE_SHIFT; /* Careful about overflow on the "+1" */ nrpages = end_index - start_index + 1; if (!nrpages) nrpages = ~0UL; /* * Ignore return value because fadvise() shall return * success even if filesystem can't retrieve a hint, */ force_page_cache_readahead(mapping, f.file, start_index, nrpages); break; case POSIX_FADV_NOREUSE: break; case POSIX_FADV_DONTNEED: if (!inode_write_congested(mapping->host)) __filemap_fdatawrite_range(mapping, offset, endbyte, WB_SYNC_NONE); /* * First and last FULL page! Partial pages are deliberately * preserved on the expectation that it is better to preserve * needed memory than to discard unneeded memory. */ start_index = (offset+(PAGE_SIZE-1)) >> PAGE_SHIFT; end_index = (endbyte >> PAGE_SHIFT); if ((endbyte & ~PAGE_MASK) != ~PAGE_MASK) { /* First page is tricky as 0 - 1 = -1, but pgoff_t * is unsigned, so the end_index >= start_index * check below would be true and we'll discard the whole * file cache which is not what was asked. */ if (end_index == 0) break; end_index--; } if (end_index >= start_index) { unsigned long count; /* * It's common to FADV_DONTNEED right after * the read or write that instantiates the * pages, in which case there will be some * sitting on the local LRU cache. Try to * avoid the expensive remote drain and the * second cache tree walk below by flushing * them out right away. */ lru_add_drain(); count = invalidate_mapping_pages(mapping, start_index, end_index); /* * If fewer pages were invalidated than expected then * it is possible that some of the pages were on * a per-cpu pagevec for a remote CPU. Drain all * pagevecs and try again. */ if (count < (end_index - start_index + 1)) { lru_add_drain_all(); invalidate_mapping_pages(mapping, start_index, end_index); } } break; default: ret = -EINVAL; } out: fdput(f); return ret; } #ifdef __ARCH_WANT_SYS_FADVISE64 SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice) { return sys_fadvise64_64(fd, offset, len, advice); } #endif
authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-11 10:17:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-11 10:17:39 -0800
commit2e4333c14de06a333783d6812cf3c4998f78b0c8 (patch)
tree368428514d70f34f2261c7f954f241f886d6bb51 /net/ipv4/fib_trie.c
parent045169816b31b10faed984b01c390db1b32ee4c1 (diff)
parentba735155b9647b6167fd50276ca0fbfbce4e836c (diff)
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS fixes from Ralf Baechle: "Two more MIPS fixes for 4.9: - RTC: Return -ENODEV so an external RTC will be tried - Fix mask of GPE frequency These two have been tested on Imagination's automated test system and also both received positive reviews on the linux-mips mailing list" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: Lantiq: Fix mask of GPE frequency MIPS: Return -ENODEV from weak implementation of rtc_mips_set_time
Diffstat (limited to 'net/ipv4/fib_trie.c')