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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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09cbfeaf1a
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
368 lines
8.4 KiB
C
368 lines
8.4 KiB
C
/*
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* linux/fs/sysv/dir.c
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*
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* minix/dir.c
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* coh/dir.c
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* Copyright (C) 1993 Pascal Haible, Bruno Haible
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*
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* sysv/dir.c
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* Copyright (C) 1993 Bruno Haible
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*
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* SystemV/Coherent directory handling functions
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*/
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/swap.h>
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#include "sysv.h"
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static int sysv_readdir(struct file *, struct dir_context *);
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const struct file_operations sysv_dir_operations = {
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.llseek = generic_file_llseek,
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.read = generic_read_dir,
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.iterate = sysv_readdir,
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.fsync = generic_file_fsync,
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};
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static inline void dir_put_page(struct page *page)
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{
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kunmap(page);
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put_page(page);
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}
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static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
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{
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struct address_space *mapping = page->mapping;
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struct inode *dir = mapping->host;
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int err = 0;
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block_write_end(NULL, mapping, pos, len, len, page, NULL);
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if (pos+len > dir->i_size) {
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i_size_write(dir, pos+len);
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mark_inode_dirty(dir);
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}
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if (IS_DIRSYNC(dir))
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err = write_one_page(page, 1);
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else
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unlock_page(page);
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return err;
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}
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static struct page * dir_get_page(struct inode *dir, unsigned long n)
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{
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struct address_space *mapping = dir->i_mapping;
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struct page *page = read_mapping_page(mapping, n, NULL);
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if (!IS_ERR(page))
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kmap(page);
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return page;
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}
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static int sysv_readdir(struct file *file, struct dir_context *ctx)
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{
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unsigned long pos = ctx->pos;
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struct inode *inode = file_inode(file);
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struct super_block *sb = inode->i_sb;
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unsigned long npages = dir_pages(inode);
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unsigned offset;
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unsigned long n;
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ctx->pos = pos = (pos + SYSV_DIRSIZE-1) & ~(SYSV_DIRSIZE-1);
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if (pos >= inode->i_size)
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return 0;
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offset = pos & ~PAGE_MASK;
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n = pos >> PAGE_SHIFT;
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for ( ; n < npages; n++, offset = 0) {
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char *kaddr, *limit;
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struct sysv_dir_entry *de;
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struct page *page = dir_get_page(inode, n);
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if (IS_ERR(page))
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continue;
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kaddr = (char *)page_address(page);
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de = (struct sysv_dir_entry *)(kaddr+offset);
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limit = kaddr + PAGE_SIZE - SYSV_DIRSIZE;
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for ( ;(char*)de <= limit; de++, ctx->pos += sizeof(*de)) {
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char *name = de->name;
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if (!de->inode)
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continue;
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if (!dir_emit(ctx, name, strnlen(name,SYSV_NAMELEN),
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fs16_to_cpu(SYSV_SB(sb), de->inode),
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DT_UNKNOWN)) {
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dir_put_page(page);
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return 0;
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}
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}
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dir_put_page(page);
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}
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return 0;
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}
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/* compare strings: name[0..len-1] (not zero-terminated) and
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* buffer[0..] (filled with zeroes up to buffer[0..maxlen-1])
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*/
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static inline int namecompare(int len, int maxlen,
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const char * name, const char * buffer)
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{
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if (len < maxlen && buffer[len])
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return 0;
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return !memcmp(name, buffer, len);
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}
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/*
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* sysv_find_entry()
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*
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* finds an entry in the specified directory with the wanted name. It
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* returns the cache buffer in which the entry was found, and the entry
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* itself (as a parameter - res_dir). It does NOT read the inode of the
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* entry - you'll have to do that yourself if you want to.
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*/
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struct sysv_dir_entry *sysv_find_entry(struct dentry *dentry, struct page **res_page)
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{
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const char * name = dentry->d_name.name;
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int namelen = dentry->d_name.len;
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struct inode * dir = d_inode(dentry->d_parent);
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unsigned long start, n;
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unsigned long npages = dir_pages(dir);
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struct page *page = NULL;
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struct sysv_dir_entry *de;
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*res_page = NULL;
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start = SYSV_I(dir)->i_dir_start_lookup;
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if (start >= npages)
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start = 0;
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n = start;
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do {
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char *kaddr;
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page = dir_get_page(dir, n);
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if (!IS_ERR(page)) {
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kaddr = (char*)page_address(page);
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de = (struct sysv_dir_entry *) kaddr;
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kaddr += PAGE_SIZE - SYSV_DIRSIZE;
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for ( ; (char *) de <= kaddr ; de++) {
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if (!de->inode)
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continue;
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if (namecompare(namelen, SYSV_NAMELEN,
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name, de->name))
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goto found;
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}
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dir_put_page(page);
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}
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if (++n >= npages)
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n = 0;
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} while (n != start);
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return NULL;
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found:
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SYSV_I(dir)->i_dir_start_lookup = n;
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*res_page = page;
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return de;
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}
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int sysv_add_link(struct dentry *dentry, struct inode *inode)
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{
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struct inode *dir = d_inode(dentry->d_parent);
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const char * name = dentry->d_name.name;
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int namelen = dentry->d_name.len;
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struct page *page = NULL;
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struct sysv_dir_entry * de;
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unsigned long npages = dir_pages(dir);
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unsigned long n;
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char *kaddr;
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loff_t pos;
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int err;
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/* We take care of directory expansion in the same loop */
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for (n = 0; n <= npages; n++) {
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page = dir_get_page(dir, n);
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err = PTR_ERR(page);
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if (IS_ERR(page))
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goto out;
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kaddr = (char*)page_address(page);
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de = (struct sysv_dir_entry *)kaddr;
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kaddr += PAGE_SIZE - SYSV_DIRSIZE;
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while ((char *)de <= kaddr) {
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if (!de->inode)
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goto got_it;
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err = -EEXIST;
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if (namecompare(namelen, SYSV_NAMELEN, name, de->name))
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goto out_page;
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de++;
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}
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dir_put_page(page);
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}
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BUG();
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return -EINVAL;
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got_it:
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pos = page_offset(page) +
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(char*)de - (char*)page_address(page);
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lock_page(page);
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err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
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if (err)
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goto out_unlock;
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memcpy (de->name, name, namelen);
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memset (de->name + namelen, 0, SYSV_DIRSIZE - namelen - 2);
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de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
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err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
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dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
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mark_inode_dirty(dir);
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out_page:
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dir_put_page(page);
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out:
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return err;
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out_unlock:
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unlock_page(page);
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goto out_page;
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}
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int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
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{
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struct inode *inode = page->mapping->host;
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char *kaddr = (char*)page_address(page);
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loff_t pos = page_offset(page) + (char *)de - kaddr;
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int err;
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lock_page(page);
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err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
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BUG_ON(err);
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de->inode = 0;
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err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
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dir_put_page(page);
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inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
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mark_inode_dirty(inode);
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return err;
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}
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int sysv_make_empty(struct inode *inode, struct inode *dir)
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{
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struct page *page = grab_cache_page(inode->i_mapping, 0);
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struct sysv_dir_entry * de;
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char *base;
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int err;
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if (!page)
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return -ENOMEM;
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err = sysv_prepare_chunk(page, 0, 2 * SYSV_DIRSIZE);
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if (err) {
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unlock_page(page);
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goto fail;
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}
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kmap(page);
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base = (char*)page_address(page);
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memset(base, 0, PAGE_SIZE);
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de = (struct sysv_dir_entry *) base;
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de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
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strcpy(de->name,".");
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de++;
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de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), dir->i_ino);
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strcpy(de->name,"..");
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kunmap(page);
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err = dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
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fail:
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put_page(page);
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return err;
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}
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/*
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* routine to check that the specified directory is empty (for rmdir)
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*/
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int sysv_empty_dir(struct inode * inode)
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{
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struct super_block *sb = inode->i_sb;
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struct page *page = NULL;
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unsigned long i, npages = dir_pages(inode);
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for (i = 0; i < npages; i++) {
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char *kaddr;
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struct sysv_dir_entry * de;
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page = dir_get_page(inode, i);
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if (IS_ERR(page))
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continue;
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kaddr = (char *)page_address(page);
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de = (struct sysv_dir_entry *)kaddr;
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kaddr += PAGE_SIZE-SYSV_DIRSIZE;
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for ( ;(char *)de <= kaddr; de++) {
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if (!de->inode)
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continue;
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/* check for . and .. */
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if (de->name[0] != '.')
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goto not_empty;
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if (!de->name[1]) {
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if (de->inode == cpu_to_fs16(SYSV_SB(sb),
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inode->i_ino))
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continue;
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goto not_empty;
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}
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if (de->name[1] != '.' || de->name[2])
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goto not_empty;
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}
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dir_put_page(page);
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}
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return 1;
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not_empty:
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dir_put_page(page);
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return 0;
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}
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/* Releases the page */
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void sysv_set_link(struct sysv_dir_entry *de, struct page *page,
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struct inode *inode)
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{
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struct inode *dir = page->mapping->host;
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loff_t pos = page_offset(page) +
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(char *)de-(char*)page_address(page);
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int err;
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lock_page(page);
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err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
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BUG_ON(err);
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de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
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err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
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dir_put_page(page);
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dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
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mark_inode_dirty(dir);
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}
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struct sysv_dir_entry * sysv_dotdot (struct inode *dir, struct page **p)
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{
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struct page *page = dir_get_page(dir, 0);
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struct sysv_dir_entry *de = NULL;
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if (!IS_ERR(page)) {
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de = (struct sysv_dir_entry*) page_address(page) + 1;
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*p = page;
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}
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return de;
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}
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ino_t sysv_inode_by_name(struct dentry *dentry)
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{
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struct page *page;
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struct sysv_dir_entry *de = sysv_find_entry (dentry, &page);
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ino_t res = 0;
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if (de) {
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res = fs16_to_cpu(SYSV_SB(dentry->d_sb), de->inode);
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dir_put_page(page);
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}
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return res;
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}
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