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4b6f5d20b0
This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
114 lines
2.6 KiB
C
114 lines
2.6 KiB
C
/*
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* dir.c
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*
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* Copyright (c) 1999 Al Smith
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*/
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#include <linux/buffer_head.h>
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#include <linux/efs_fs.h>
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#include <linux/smp_lock.h>
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static int efs_readdir(struct file *, void *, filldir_t);
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const struct file_operations efs_dir_operations = {
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.read = generic_read_dir,
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.readdir = efs_readdir,
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};
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struct inode_operations efs_dir_inode_operations = {
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.lookup = efs_lookup,
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};
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static int efs_readdir(struct file *filp, void *dirent, filldir_t filldir) {
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struct inode *inode = filp->f_dentry->d_inode;
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struct buffer_head *bh;
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struct efs_dir *dirblock;
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struct efs_dentry *dirslot;
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efs_ino_t inodenum;
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efs_block_t block;
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int slot, namelen;
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char *nameptr;
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if (inode->i_size & (EFS_DIRBSIZE-1))
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printk(KERN_WARNING "EFS: WARNING: readdir(): directory size not a multiple of EFS_DIRBSIZE\n");
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lock_kernel();
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/* work out where this entry can be found */
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block = filp->f_pos >> EFS_DIRBSIZE_BITS;
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/* each block contains at most 256 slots */
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slot = filp->f_pos & 0xff;
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/* look at all blocks */
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while (block < inode->i_blocks) {
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/* read the dir block */
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bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
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if (!bh) {
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printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);
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break;
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}
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dirblock = (struct efs_dir *) bh->b_data;
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if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
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printk(KERN_ERR "EFS: readdir(): invalid directory block\n");
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brelse(bh);
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break;
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}
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while (slot < dirblock->slots) {
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if (dirblock->space[slot] == 0) {
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slot++;
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continue;
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}
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dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
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inodenum = be32_to_cpu(dirslot->inode);
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namelen = dirslot->namelen;
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nameptr = dirslot->name;
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#ifdef DEBUG
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printk(KERN_DEBUG "EFS: readdir(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", block, slot, dirblock->slots-1, inodenum, nameptr, namelen);
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#endif
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if (namelen > 0) {
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/* found the next entry */
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filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
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/* copy filename and data in dirslot */
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filldir(dirent, nameptr, namelen, filp->f_pos, inodenum, DT_UNKNOWN);
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/* sanity check */
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if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
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printk(KERN_WARNING "EFS: directory entry %d exceeds directory block\n", slot);
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slot++;
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continue;
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}
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/* store position of next slot */
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if (++slot == dirblock->slots) {
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slot = 0;
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block++;
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}
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brelse(bh);
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filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
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goto out;
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}
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slot++;
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}
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brelse(bh);
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slot = 0;
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block++;
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}
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filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
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out:
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unlock_kernel();
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return 0;
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}
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