754661f143
Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
113 lines
2.7 KiB
C
113 lines
2.7 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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const 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_path.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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