/fs/gfs2/dir.c
C | 2197 lines | 1569 code | 313 blank | 315 comment | 284 complexity | 98b4814a62280bdfb83b20b9a9d7b763 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
- /*
- * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
- * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
- *
- * This copyrighted material is made available to anyone wishing to use,
- * modify, copy, or redistribute it subject to the terms and conditions
- * of the GNU General Public License version 2.
- */
- /*
- * Implements Extendible Hashing as described in:
- * "Extendible Hashing" by Fagin, et al in
- * __ACM Trans. on Database Systems__, Sept 1979.
- *
- *
- * Here's the layout of dirents which is essentially the same as that of ext2
- * within a single block. The field de_name_len is the number of bytes
- * actually required for the name (no null terminator). The field de_rec_len
- * is the number of bytes allocated to the dirent. The offset of the next
- * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is
- * deleted, the preceding dirent inherits its allocated space, ie
- * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained
- * by adding de_rec_len to the current dirent, this essentially causes the
- * deleted dirent to get jumped over when iterating through all the dirents.
- *
- * When deleting the first dirent in a block, there is no previous dirent so
- * the field de_ino is set to zero to designate it as deleted. When allocating
- * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the
- * first dirent has (de_ino == 0) and de_rec_len is large enough, this first
- * dirent is allocated. Otherwise it must go through all the 'used' dirents
- * searching for one in which the amount of total space minus the amount of
- * used space will provide enough space for the new dirent.
- *
- * There are two types of blocks in which dirents reside. In a stuffed dinode,
- * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of
- * the block. In leaves, they begin at offset sizeof(struct gfs2_leaf) from the
- * beginning of the leaf block. The dirents reside in leaves when
- *
- * dip->i_diskflags & GFS2_DIF_EXHASH is true
- *
- * Otherwise, the dirents are "linear", within a single stuffed dinode block.
- *
- * When the dirents are in leaves, the actual contents of the directory file are
- * used as an array of 64-bit block pointers pointing to the leaf blocks. The
- * dirents are NOT in the directory file itself. There can be more than one
- * block pointer in the array that points to the same leaf. In fact, when a
- * directory is first converted from linear to exhash, all of the pointers
- * point to the same leaf.
- *
- * When a leaf is completely full, the size of the hash table can be
- * doubled unless it is already at the maximum size which is hard coded into
- * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list,
- * but never before the maximum hash table size has been reached.
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #include <linux/slab.h>
- #include <linux/spinlock.h>
- #include <linux/buffer_head.h>
- #include <linux/sort.h>
- #include <linux/gfs2_ondisk.h>
- #include <linux/crc32.h>
- #include <linux/vmalloc.h>
- #include <linux/bio.h>
- #include "gfs2.h"
- #include "incore.h"
- #include "dir.h"
- #include "glock.h"
- #include "inode.h"
- #include "meta_io.h"
- #include "quota.h"
- #include "rgrp.h"
- #include "trans.h"
- #include "bmap.h"
- #include "util.h"
- #define IS_LEAF 1 /* Hashed (leaf) directory */
- #define IS_DINODE 2 /* Linear (stuffed dinode block) directory */
- #define MAX_RA_BLOCKS 32 /* max read-ahead blocks */
- #define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
- #define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
- #define GFS2_HASH_INDEX_MASK 0xffffc000
- #define GFS2_USE_HASH_FLAG 0x2000
- struct qstr gfs2_qdot __read_mostly;
- struct qstr gfs2_qdotdot __read_mostly;
- typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
- const struct qstr *name, void *opaque);
- int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
- struct buffer_head **bhp)
- {
- struct buffer_head *bh;
- bh = gfs2_meta_new(ip->i_gl, block);
- gfs2_trans_add_meta(ip->i_gl, bh);
- gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
- gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
- *bhp = bh;
- return 0;
- }
- static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
- struct buffer_head **bhp)
- {
- struct buffer_head *bh;
- int error;
- error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, 0, &bh);
- if (error)
- return error;
- if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
- brelse(bh);
- return -EIO;
- }
- *bhp = bh;
- return 0;
- }
- static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
- unsigned int offset, unsigned int size)
- {
- struct buffer_head *dibh;
- int error;
- error = gfs2_meta_inode_buffer(ip, &dibh);
- if (error)
- return error;
- gfs2_trans_add_meta(ip->i_gl, dibh);
- memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
- if (ip->i_inode.i_size < offset + size)
- i_size_write(&ip->i_inode, offset + size);
- ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
- gfs2_dinode_out(ip, dibh->b_data);
- brelse(dibh);
- return size;
- }
- /**
- * gfs2_dir_write_data - Write directory information to the inode
- * @ip: The GFS2 inode
- * @buf: The buffer containing information to be written
- * @offset: The file offset to start writing at
- * @size: The amount of data to write
- *
- * Returns: The number of bytes correctly written or error code
- */
- static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
- u64 offset, unsigned int size)
- {
- struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
- struct buffer_head *dibh;
- u64 lblock, dblock;
- u32 extlen = 0;
- unsigned int o;
- int copied = 0;
- int error = 0;
- int new = 0;
- if (!size)
- return 0;
- if (gfs2_is_stuffed(ip) &&
- offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
- return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
- size);
- if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
- return -EINVAL;
- if (gfs2_is_stuffed(ip)) {
- error = gfs2_unstuff_dinode(ip, NULL);
- if (error)
- return error;
- }
- lblock = offset;
- o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
- while (copied < size) {
- unsigned int amount;
- struct buffer_head *bh;
- amount = size - copied;
- if (amount > sdp->sd_sb.sb_bsize - o)
- amount = sdp->sd_sb.sb_bsize - o;
- if (!extlen) {
- new = 1;
- error = gfs2_extent_map(&ip->i_inode, lblock, &new,
- &dblock, &extlen);
- if (error)
- goto fail;
- error = -EIO;
- if (gfs2_assert_withdraw(sdp, dblock))
- goto fail;
- }
- if (amount == sdp->sd_jbsize || new)
- error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
- else
- error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
- if (error)
- goto fail;
- gfs2_trans_add_meta(ip->i_gl, bh);
- memcpy(bh->b_data + o, buf, amount);
- brelse(bh);
- buf += amount;
- copied += amount;
- lblock++;
- dblock++;
- extlen--;
- o = sizeof(struct gfs2_meta_header);
- }
- out:
- error = gfs2_meta_inode_buffer(ip, &dibh);
- if (error)
- return error;
- if (ip->i_inode.i_size < offset + copied)
- i_size_write(&ip->i_inode, offset + copied);
- ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
- gfs2_trans_add_meta(ip->i_gl, dibh);
- gfs2_dinode_out(ip, dibh->b_data);
- brelse(dibh);
- return copied;
- fail:
- if (copied)
- goto out;
- return error;
- }
- static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf,
- unsigned int size)
- {
- struct buffer_head *dibh;
- int error;
- error = gfs2_meta_inode_buffer(ip, &dibh);
- if (!error) {
- memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
- brelse(dibh);
- }
- return (error) ? error : size;
- }
- /**
- * gfs2_dir_read_data - Read a data from a directory inode
- * @ip: The GFS2 Inode
- * @buf: The buffer to place result into
- * @size: Amount of data to transfer
- *
- * Returns: The amount of data actually copied or the error
- */
- static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
- unsigned int size)
- {
- struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
- u64 lblock, dblock;
- u32 extlen = 0;
- unsigned int o;
- int copied = 0;
- int error = 0;
- if (gfs2_is_stuffed(ip))
- return gfs2_dir_read_stuffed(ip, buf, size);
- if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
- return -EINVAL;
- lblock = 0;
- o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
- while (copied < size) {
- unsigned int amount;
- struct buffer_head *bh;
- int new;
- amount = size - copied;
- if (amount > sdp->sd_sb.sb_bsize - o)
- amount = sdp->sd_sb.sb_bsize - o;
- if (!extlen) {
- new = 0;
- error = gfs2_extent_map(&ip->i_inode, lblock, &new,
- &dblock, &extlen);
- if (error || !dblock)
- goto fail;
- BUG_ON(extlen < 1);
- bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
- } else {
- error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, 0, &bh);
- if (error)
- goto fail;
- }
- error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
- if (error) {
- brelse(bh);
- goto fail;
- }
- dblock++;
- extlen--;
- memcpy(buf, bh->b_data + o, amount);
- brelse(bh);
- buf += (amount/sizeof(__be64));
- copied += amount;
- lblock++;
- o = sizeof(struct gfs2_meta_header);
- }
- return copied;
- fail:
- return (copied) ? copied : error;
- }
- /**
- * gfs2_dir_get_hash_table - Get pointer to the dir hash table
- * @ip: The inode in question
- *
- * Returns: The hash table or an error
- */
- static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
- {
- struct inode *inode = &ip->i_inode;
- int ret;
- u32 hsize;
- __be64 *hc;
- BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH));
- hc = ip->i_hash_cache;
- if (hc)
- return hc;
- hsize = BIT(ip->i_depth);
- hsize *= sizeof(__be64);
- if (hsize != i_size_read(&ip->i_inode)) {
- gfs2_consist_inode(ip);
- return ERR_PTR(-EIO);
- }
- hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
- if (hc == NULL)
- hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
- if (hc == NULL)
- return ERR_PTR(-ENOMEM);
- ret = gfs2_dir_read_data(ip, hc, hsize);
- if (ret < 0) {
- kvfree(hc);
- return ERR_PTR(ret);
- }
- spin_lock(&inode->i_lock);
- if (likely(!ip->i_hash_cache)) {
- ip->i_hash_cache = hc;
- hc = NULL;
- }
- spin_unlock(&inode->i_lock);
- kvfree(hc);
- return ip->i_hash_cache;
- }
- /**
- * gfs2_dir_hash_inval - Invalidate dir hash
- * @ip: The directory inode
- *
- * Must be called with an exclusive glock, or during glock invalidation.
- */
- void gfs2_dir_hash_inval(struct gfs2_inode *ip)
- {
- __be64 *hc;
- spin_lock(&ip->i_inode.i_lock);
- hc = ip->i_hash_cache;
- ip->i_hash_cache = NULL;
- spin_unlock(&ip->i_inode.i_lock);
- kvfree(hc);
- }
- static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
- {
- return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
- }
- static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
- const struct qstr *name, int ret)
- {
- if (!gfs2_dirent_sentinel(dent) &&
- be32_to_cpu(dent->de_hash) == name->hash &&
- be16_to_cpu(dent->de_name_len) == name->len &&
- memcmp(dent+1, name->name, name->len) == 0)
- return ret;
- return 0;
- }
- static int gfs2_dirent_find(const struct gfs2_dirent *dent,
- const struct qstr *name,
- void *opaque)
- {
- return __gfs2_dirent_find(dent, name, 1);
- }
- static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
- const struct qstr *name,
- void *opaque)
- {
- return __gfs2_dirent_find(dent, name, 2);
- }
- /*
- * name->name holds ptr to start of block.
- * name->len holds size of block.
- */
- static int gfs2_dirent_last(const struct gfs2_dirent *dent,
- const struct qstr *name,
- void *opaque)
- {
- const char *start = name->name;
- const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
- if (name->len == (end - start))
- return 1;
- return 0;
- }
- /* Look for the dirent that contains the offset specified in data. Once we
- * find that dirent, there must be space available there for the new dirent */
- static int gfs2_dirent_find_offset(const struct gfs2_dirent *dent,
- const struct qstr *name,
- void *ptr)
- {
- unsigned required = GFS2_DIRENT_SIZE(name->len);
- unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
- unsigned totlen = be16_to_cpu(dent->de_rec_len);
- if (ptr < (void *)dent || ptr >= (void *)dent + totlen)
- return 0;
- if (gfs2_dirent_sentinel(dent))
- actual = 0;
- if (ptr < (void *)dent + actual)
- return -1;
- if ((void *)dent + totlen >= ptr + required)
- return 1;
- return -1;
- }
- static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
- const struct qstr *name,
- void *opaque)
- {
- unsigned required = GFS2_DIRENT_SIZE(name->len);
- unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
- unsigned totlen = be16_to_cpu(dent->de_rec_len);
- if (gfs2_dirent_sentinel(dent))
- actual = 0;
- if (totlen - actual >= required)
- return 1;
- return 0;
- }
- struct dirent_gather {
- const struct gfs2_dirent **pdent;
- unsigned offset;
- };
- static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
- const struct qstr *name,
- void *opaque)
- {
- struct dirent_gather *g = opaque;
- if (!gfs2_dirent_sentinel(dent)) {
- g->pdent[g->offset++] = dent;
- }
- return 0;
- }
- /*
- * Other possible things to check:
- * - Inode located within filesystem size (and on valid block)
- * - Valid directory entry type
- * Not sure how heavy-weight we want to make this... could also check
- * hash is correct for example, but that would take a lot of extra time.
- * For now the most important thing is to check that the various sizes
- * are correct.
- */
- static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
- unsigned int size, unsigned int len, int first)
- {
- const char *msg = "gfs2_dirent too small";
- if (unlikely(size < sizeof(struct gfs2_dirent)))
- goto error;
- msg = "gfs2_dirent misaligned";
- if (unlikely(offset & 0x7))
- goto error;
- msg = "gfs2_dirent points beyond end of block";
- if (unlikely(offset + size > len))
- goto error;
- msg = "zero inode number";
- if (unlikely(!first && gfs2_dirent_sentinel(dent)))
- goto error;
- msg = "name length is greater than space in dirent";
- if (!gfs2_dirent_sentinel(dent) &&
- unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
- size))
- goto error;
- return 0;
- error:
- pr_warn("%s: %s (%s)\n",
- __func__, msg, first ? "first in block" : "not first in block");
- return -EIO;
- }
- static int gfs2_dirent_offset(const void *buf)
- {
- const struct gfs2_meta_header *h = buf;
- int offset;
- BUG_ON(buf == NULL);
- switch(be32_to_cpu(h->mh_type)) {
- case GFS2_METATYPE_LF:
- offset = sizeof(struct gfs2_leaf);
- break;
- case GFS2_METATYPE_DI:
- offset = sizeof(struct gfs2_dinode);
- break;
- default:
- goto wrong_type;
- }
- return offset;
- wrong_type:
- pr_warn("%s: wrong block type %u\n", __func__, be32_to_cpu(h->mh_type));
- return -1;
- }
- static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
- unsigned int len, gfs2_dscan_t scan,
- const struct qstr *name,
- void *opaque)
- {
- struct gfs2_dirent *dent, *prev;
- unsigned offset;
- unsigned size;
- int ret = 0;
- ret = gfs2_dirent_offset(buf);
- if (ret < 0)
- goto consist_inode;
- offset = ret;
- prev = NULL;
- dent = buf + offset;
- size = be16_to_cpu(dent->de_rec_len);
- if (gfs2_check_dirent(dent, offset, size, len, 1))
- goto consist_inode;
- do {
- ret = scan(dent, name, opaque);
- if (ret)
- break;
- offset += size;
- if (offset == len)
- break;
- prev = dent;
- dent = buf + offset;
- size = be16_to_cpu(dent->de_rec_len);
- if (gfs2_check_dirent(dent, offset, size, len, 0))
- goto consist_inode;
- } while(1);
- switch(ret) {
- case 0:
- return NULL;
- case 1:
- return dent;
- case 2:
- return prev ? prev : dent;
- default:
- BUG_ON(ret > 0);
- return ERR_PTR(ret);
- }
- consist_inode:
- gfs2_consist_inode(GFS2_I(inode));
- return ERR_PTR(-EIO);
- }
- static int dirent_check_reclen(struct gfs2_inode *dip,
- const struct gfs2_dirent *d, const void *end_p)
- {
- const void *ptr = d;
- u16 rec_len = be16_to_cpu(d->de_rec_len);
- if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
- goto broken;
- ptr += rec_len;
- if (ptr < end_p)
- return rec_len;
- if (ptr == end_p)
- return -ENOENT;
- broken:
- gfs2_consist_inode(dip);
- return -EIO;
- }
- /**
- * dirent_next - Next dirent
- * @dip: the directory
- * @bh: The buffer
- * @dent: Pointer to list of dirents
- *
- * Returns: 0 on success, error code otherwise
- */
- static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
- struct gfs2_dirent **dent)
- {
- struct gfs2_dirent *cur = *dent, *tmp;
- char *bh_end = bh->b_data + bh->b_size;
- int ret;
- ret = dirent_check_reclen(dip, cur, bh_end);
- if (ret < 0)
- return ret;
- tmp = (void *)cur + ret;
- ret = dirent_check_reclen(dip, tmp, bh_end);
- if (ret == -EIO)
- return ret;
- /* Only the first dent could ever have de_inum.no_addr == 0 */
- if (gfs2_dirent_sentinel(tmp)) {
- gfs2_consist_inode(dip);
- return -EIO;
- }
- *dent = tmp;
- return 0;
- }
- /**
- * dirent_del - Delete a dirent
- * @dip: The GFS2 inode
- * @bh: The buffer
- * @prev: The previous dirent
- * @cur: The current dirent
- *
- */
- static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
- struct gfs2_dirent *prev, struct gfs2_dirent *cur)
- {
- u16 cur_rec_len, prev_rec_len;
- if (gfs2_dirent_sentinel(cur)) {
- gfs2_consist_inode(dip);
- return;
- }
- gfs2_trans_add_meta(dip->i_gl, bh);
- /* If there is no prev entry, this is the first entry in the block.
- The de_rec_len is already as big as it needs to be. Just zero
- out the inode number and return. */
- if (!prev) {
- cur->de_inum.no_addr = 0;
- cur->de_inum.no_formal_ino = 0;
- return;
- }
- /* Combine this dentry with the previous one. */
- prev_rec_len = be16_to_cpu(prev->de_rec_len);
- cur_rec_len = be16_to_cpu(cur->de_rec_len);
- if ((char *)prev + prev_rec_len != (char *)cur)
- gfs2_consist_inode(dip);
- if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
- gfs2_consist_inode(dip);
- prev_rec_len += cur_rec_len;
- prev->de_rec_len = cpu_to_be16(prev_rec_len);
- }
- static struct gfs2_dirent *do_init_dirent(struct inode *inode,
- struct gfs2_dirent *dent,
- const struct qstr *name,
- struct buffer_head *bh,
- unsigned offset)
- {
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_dirent *ndent;
- unsigned totlen;
- totlen = be16_to_cpu(dent->de_rec_len);
- BUG_ON(offset + name->len > totlen);
- gfs2_trans_add_meta(ip->i_gl, bh);
- ndent = (struct gfs2_dirent *)((char *)dent + offset);
- dent->de_rec_len = cpu_to_be16(offset);
- gfs2_qstr2dirent(name, totlen - offset, ndent);
- return ndent;
- }
- /*
- * Takes a dent from which to grab space as an argument. Returns the
- * newly created dent.
- */
- static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
- struct gfs2_dirent *dent,
- const struct qstr *name,
- struct buffer_head *bh)
- {
- unsigned offset = 0;
- if (!gfs2_dirent_sentinel(dent))
- offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
- return do_init_dirent(inode, dent, name, bh, offset);
- }
- static struct gfs2_dirent *gfs2_dirent_split_alloc(struct inode *inode,
- struct buffer_head *bh,
- const struct qstr *name,
- void *ptr)
- {
- struct gfs2_dirent *dent;
- dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
- gfs2_dirent_find_offset, name, ptr);
- if (!dent || IS_ERR(dent))
- return dent;
- return do_init_dirent(inode, dent, name, bh,
- (unsigned)(ptr - (void *)dent));
- }
- static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
- struct buffer_head **bhp)
- {
- int error;
- error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, 0, bhp);
- if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
- /* pr_info("block num=%llu\n", leaf_no); */
- error = -EIO;
- }
- return error;
- }
- /**
- * get_leaf_nr - Get a leaf number associated with the index
- * @dip: The GFS2 inode
- * @index:
- * @leaf_out:
- *
- * Returns: 0 on success, error code otherwise
- */
- static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
- u64 *leaf_out)
- {
- __be64 *hash;
- int error;
- hash = gfs2_dir_get_hash_table(dip);
- error = PTR_ERR_OR_ZERO(hash);
- if (!error)
- *leaf_out = be64_to_cpu(*(hash + index));
- return error;
- }
- static int get_first_leaf(struct gfs2_inode *dip, u32 index,
- struct buffer_head **bh_out)
- {
- u64 leaf_no;
- int error;
- error = get_leaf_nr(dip, index, &leaf_no);
- if (!error)
- error = get_leaf(dip, leaf_no, bh_out);
- return error;
- }
- static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
- const struct qstr *name,
- gfs2_dscan_t scan,
- struct buffer_head **pbh)
- {
- struct buffer_head *bh;
- struct gfs2_dirent *dent;
- struct gfs2_inode *ip = GFS2_I(inode);
- int error;
- if (ip->i_diskflags & GFS2_DIF_EXHASH) {
- struct gfs2_leaf *leaf;
- unsigned int hsize = BIT(ip->i_depth);
- unsigned int index;
- u64 ln;
- if (hsize * sizeof(u64) != i_size_read(inode)) {
- gfs2_consist_inode(ip);
- return ERR_PTR(-EIO);
- }
- index = name->hash >> (32 - ip->i_depth);
- error = get_first_leaf(ip, index, &bh);
- if (error)
- return ERR_PTR(error);
- do {
- dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
- scan, name, NULL);
- if (dent)
- goto got_dent;
- leaf = (struct gfs2_leaf *)bh->b_data;
- ln = be64_to_cpu(leaf->lf_next);
- brelse(bh);
- if (!ln)
- break;
- error = get_leaf(ip, ln, &bh);
- } while(!error);
- return error ? ERR_PTR(error) : NULL;
- }
- error = gfs2_meta_inode_buffer(ip, &bh);
- if (error)
- return ERR_PTR(error);
- dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
- got_dent:
- if (unlikely(dent == NULL || IS_ERR(dent))) {
- brelse(bh);
- bh = NULL;
- }
- *pbh = bh;
- return dent;
- }
- static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
- {
- struct gfs2_inode *ip = GFS2_I(inode);
- unsigned int n = 1;
- u64 bn;
- int error;
- struct buffer_head *bh;
- struct gfs2_leaf *leaf;
- struct gfs2_dirent *dent;
- struct timespec tv = current_time(inode);
- error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
- if (error)
- return NULL;
- bh = gfs2_meta_new(ip->i_gl, bn);
- if (!bh)
- return NULL;
- gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
- gfs2_trans_add_meta(ip->i_gl, bh);
- gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
- leaf = (struct gfs2_leaf *)bh->b_data;
- leaf->lf_depth = cpu_to_be16(depth);
- leaf->lf_entries = 0;
- leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
- leaf->lf_next = 0;
- leaf->lf_inode = cpu_to_be64(ip->i_no_addr);
- leaf->lf_dist = cpu_to_be32(1);
- leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
- leaf->lf_sec = cpu_to_be64(tv.tv_sec);
- memset(leaf->lf_reserved2, 0, sizeof(leaf->lf_reserved2));
- dent = (struct gfs2_dirent *)(leaf+1);
- gfs2_qstr2dirent(&empty_name, bh->b_size - sizeof(struct gfs2_leaf), dent);
- *pbh = bh;
- return leaf;
- }
- /**
- * dir_make_exhash - Convert a stuffed directory into an ExHash directory
- * @dip: The GFS2 inode
- *
- * Returns: 0 on success, error code otherwise
- */
- static int dir_make_exhash(struct inode *inode)
- {
- struct gfs2_inode *dip = GFS2_I(inode);
- struct gfs2_sbd *sdp = GFS2_SB(inode);
- struct gfs2_dirent *dent;
- struct qstr args;
- struct buffer_head *bh, *dibh;
- struct gfs2_leaf *leaf;
- int y;
- u32 x;
- __be64 *lp;
- u64 bn;
- int error;
- error = gfs2_meta_inode_buffer(dip, &dibh);
- if (error)
- return error;
- /* Turn over a new leaf */
- leaf = new_leaf(inode, &bh, 0);
- if (!leaf)
- return -ENOSPC;
- bn = bh->b_blocknr;
- gfs2_assert(sdp, dip->i_entries < BIT(16));
- leaf->lf_entries = cpu_to_be16(dip->i_entries);
- /* Copy dirents */
- gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
- sizeof(struct gfs2_dinode));
- /* Find last entry */
- x = 0;
- args.len = bh->b_size - sizeof(struct gfs2_dinode) +
- sizeof(struct gfs2_leaf);
- args.name = bh->b_data;
- dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
- gfs2_dirent_last, &args, NULL);
- if (!dent) {
- brelse(bh);
- brelse(dibh);
- return -EIO;
- }
- if (IS_ERR(dent)) {
- brelse(bh);
- brelse(dibh);
- return PTR_ERR(dent);
- }
- /* Adjust the last dirent's record length
- (Remember that dent still points to the last entry.) */
- dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
- sizeof(struct gfs2_dinode) -
- sizeof(struct gfs2_leaf));
- brelse(bh);
- /* We're done with the new leaf block, now setup the new
- hash table. */
- gfs2_trans_add_meta(dip->i_gl, dibh);
- gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
- lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
- for (x = sdp->sd_hash_ptrs; x--; lp++)
- *lp = cpu_to_be64(bn);
- i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
- gfs2_add_inode_blocks(&dip->i_inode, 1);
- dip->i_diskflags |= GFS2_DIF_EXHASH;
- for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
- dip->i_depth = y;
- gfs2_dinode_out(dip, dibh->b_data);
- brelse(dibh);
- return 0;
- }
- /**
- * dir_split_leaf - Split a leaf block into two
- * @dip: The GFS2 inode
- * @index:
- * @leaf_no:
- *
- * Returns: 0 on success, error code on failure
- */
- static int dir_split_leaf(struct inode *inode, const struct qstr *name)
- {
- struct gfs2_inode *dip = GFS2_I(inode);
- struct buffer_head *nbh, *obh, *dibh;
- struct gfs2_leaf *nleaf, *oleaf;
- struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
- u32 start, len, half_len, divider;
- u64 bn, leaf_no;
- __be64 *lp;
- u32 index;
- int x, moved = 0;
- int error;
- index = name->hash >> (32 - dip->i_depth);
- error = get_leaf_nr(dip, index, &leaf_no);
- if (error)
- return error;
- /* Get the old leaf block */
- error = get_leaf(dip, leaf_no, &obh);
- if (error)
- return error;
- oleaf = (struct gfs2_leaf *)obh->b_data;
- if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
- brelse(obh);
- return 1; /* can't split */
- }
- gfs2_trans_add_meta(dip->i_gl, obh);
- nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
- if (!nleaf) {
- brelse(obh);
- return -ENOSPC;
- }
- bn = nbh->b_blocknr;
- /* Compute the start and len of leaf pointers in the hash table. */
- len = BIT(dip->i_depth - be16_to_cpu(oleaf->lf_depth));
- half_len = len >> 1;
- if (!half_len) {
- pr_warn("i_depth %u lf_depth %u index %u\n",
- dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
- gfs2_consist_inode(dip);
- error = -EIO;
- goto fail_brelse;
- }
- start = (index & ~(len - 1));
- /* Change the pointers.
- Don't bother distinguishing stuffed from non-stuffed.
- This code is complicated enough already. */
- lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
- if (!lp) {
- error = -ENOMEM;
- goto fail_brelse;
- }
- /* Change the pointers */
- for (x = 0; x < half_len; x++)
- lp[x] = cpu_to_be64(bn);
- gfs2_dir_hash_inval(dip);
- error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
- half_len * sizeof(u64));
- if (error != half_len * sizeof(u64)) {
- if (error >= 0)
- error = -EIO;
- goto fail_lpfree;
- }
- kfree(lp);
- /* Compute the divider */
- divider = (start + half_len) << (32 - dip->i_depth);
- /* Copy the entries */
- dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
- do {
- next = dent;
- if (dirent_next(dip, obh, &next))
- next = NULL;
- if (!gfs2_dirent_sentinel(dent) &&
- be32_to_cpu(dent->de_hash) < divider) {
- struct qstr str;
- void *ptr = ((char *)dent - obh->b_data) + nbh->b_data;
- str.name = (char*)(dent+1);
- str.len = be16_to_cpu(dent->de_name_len);
- str.hash = be32_to_cpu(dent->de_hash);
- new = gfs2_dirent_split_alloc(inode, nbh, &str, ptr);
- if (IS_ERR(new)) {
- error = PTR_ERR(new);
- break;
- }
- new->de_inum = dent->de_inum; /* No endian worries */
- new->de_type = dent->de_type; /* No endian worries */
- be16_add_cpu(&nleaf->lf_entries, 1);
- dirent_del(dip, obh, prev, dent);
- if (!oleaf->lf_entries)
- gfs2_consist_inode(dip);
- be16_add_cpu(&oleaf->lf_entries, -1);
- if (!prev)
- prev = dent;
- moved = 1;
- } else {
- prev = dent;
- }
- dent = next;
- } while (dent);
- oleaf->lf_depth = nleaf->lf_depth;
- error = gfs2_meta_inode_buffer(dip, &dibh);
- if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
- gfs2_trans_add_meta(dip->i_gl, dibh);
- gfs2_add_inode_blocks(&dip->i_inode, 1);
- gfs2_dinode_out(dip, dibh->b_data);
- brelse(dibh);
- }
- brelse(obh);
- brelse(nbh);
- return error;
- fail_lpfree:
- kfree(lp);
- fail_brelse:
- brelse(obh);
- brelse(nbh);
- return error;
- }
- /**
- * dir_double_exhash - Double size of ExHash table
- * @dip: The GFS2 dinode
- *
- * Returns: 0 on success, error code on failure
- */
- static int dir_double_exhash(struct gfs2_inode *dip)
- {
- struct buffer_head *dibh;
- u32 hsize;
- u32 hsize_bytes;
- __be64 *hc;
- __be64 *hc2, *h;
- int x;
- int error = 0;
- hsize = BIT(dip->i_depth);
- hsize_bytes = hsize * sizeof(__be64);
- hc = gfs2_dir_get_hash_table(dip);
- if (IS_ERR(hc))
- return PTR_ERR(hc);
- hc2 = kmalloc(hsize_bytes * 2, GFP_NOFS | __GFP_NOWARN);
- if (hc2 == NULL)
- hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS, PAGE_KERNEL);
- if (!hc2)
- return -ENOMEM;
- h = hc2;
- error = gfs2_meta_inode_buffer(dip, &dibh);
- if (error)
- goto out_kfree;
- for (x = 0; x < hsize; x++) {
- *h++ = *hc;
- *h++ = *hc;
- hc++;
- }
- error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2);
- if (error != (hsize_bytes * 2))
- goto fail;
- gfs2_dir_hash_inval(dip);
- dip->i_hash_cache = hc2;
- dip->i_depth++;
- gfs2_dinode_out(dip, dibh->b_data);
- brelse(dibh);
- return 0;
- fail:
- /* Replace original hash table & size */
- gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes);
- i_size_write(&dip->i_inode, hsize_bytes);
- gfs2_dinode_out(dip, dibh->b_data);
- brelse(dibh);
- out_kfree:
- kvfree(hc2);
- return error;
- }
- /**
- * compare_dents - compare directory entries by hash value
- * @a: first dent
- * @b: second dent
- *
- * When comparing the hash entries of @a to @b:
- * gt: returns 1
- * lt: returns -1
- * eq: returns 0
- */
- static int compare_dents(const void *a, const void *b)
- {
- const struct gfs2_dirent *dent_a, *dent_b;
- u32 hash_a, hash_b;
- int ret = 0;
- dent_a = *(const struct gfs2_dirent **)a;
- hash_a = dent_a->de_cookie;
- dent_b = *(const struct gfs2_dirent **)b;
- hash_b = dent_b->de_cookie;
- if (hash_a > hash_b)
- ret = 1;
- else if (hash_a < hash_b)
- ret = -1;
- else {
- unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
- unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
- if (len_a > len_b)
- ret = 1;
- else if (len_a < len_b)
- ret = -1;
- else
- ret = memcmp(dent_a + 1, dent_b + 1, len_a);
- }
- return ret;
- }
- /**
- * do_filldir_main - read out directory entries
- * @dip: The GFS2 inode
- * @ctx: what to feed the entries to
- * @darr: an array of struct gfs2_dirent pointers to read
- * @entries: the number of entries in darr
- * @copied: pointer to int that's non-zero if a entry has been copied out
- *
- * Jump through some hoops to make sure that if there are hash collsions,
- * they are read out at the beginning of a buffer. We want to minimize
- * the possibility that they will fall into different readdir buffers or
- * that someone will want to seek to that location.
- *
- * Returns: errno, >0 if the actor tells you to stop
- */
- static int do_filldir_main(struct gfs2_inode *dip, struct dir_context *ctx,
- struct gfs2_dirent **darr, u32 entries,
- u32 sort_start, int *copied)
- {
- const struct gfs2_dirent *dent, *dent_next;
- u64 off, off_next;
- unsigned int x, y;
- int run = 0;
- if (sort_start < entries)
- sort(&darr[sort_start], entries - sort_start,
- sizeof(struct gfs2_dirent *), compare_dents, NULL);
- dent_next = darr[0];
- off_next = dent_next->de_cookie;
- for (x = 0, y = 1; x < entries; x++, y++) {
- dent = dent_next;
- off = off_next;
- if (y < entries) {
- dent_next = darr[y];
- off_next = dent_next->de_cookie;
- if (off < ctx->pos)
- continue;
- ctx->pos = off;
- if (off_next == off) {
- if (*copied && !run)
- return 1;
- run = 1;
- } else
- run = 0;
- } else {
- if (off < ctx->pos)
- continue;
- ctx->pos = off;
- }
- if (!dir_emit(ctx, (const char *)(dent + 1),
- be16_to_cpu(dent->de_name_len),
- be64_to_cpu(dent->de_inum.no_addr),
- be16_to_cpu(dent->de_type)))
- return 1;
- *copied = 1;
- }
- /* Increment the ctx->pos by one, so the next time we come into the
- do_filldir fxn, we get the next entry instead of the last one in the
- current leaf */
- ctx->pos++;
- return 0;
- }
- static void *gfs2_alloc_sort_buffer(unsigned size)
- {
- void *ptr = NULL;
- if (size < KMALLOC_MAX_SIZE)
- ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
- if (!ptr)
- ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
- return ptr;
- }
- static int gfs2_set_cookies(struct gfs2_sbd *sdp, struct buffer_head *bh,
- unsigned leaf_nr, struct gfs2_dirent **darr,
- unsigned entries)
- {
- int sort_id = -1;
- int i;
-
- for (i = 0; i < entries; i++) {
- unsigned offset;
- darr[i]->de_cookie = be32_to_cpu(darr[i]->de_hash);
- darr[i]->de_cookie = gfs2_disk_hash2offset(darr[i]->de_cookie);
- if (!sdp->sd_args.ar_loccookie)
- continue;
- offset = (char *)(darr[i]) -
- (bh->b_data + gfs2_dirent_offset(bh->b_data));
- offset /= GFS2_MIN_DIRENT_SIZE;
- offset += leaf_nr * sdp->sd_max_dents_per_leaf;
- if (offset >= GFS2_USE_HASH_FLAG ||
- leaf_nr >= GFS2_USE_HASH_FLAG) {
- darr[i]->de_cookie |= GFS2_USE_HASH_FLAG;
- if (sort_id < 0)
- sort_id = i;
- continue;
- }
- darr[i]->de_cookie &= GFS2_HASH_INDEX_MASK;
- darr[i]->de_cookie |= offset;
- }
- return sort_id;
- }
- static int gfs2_dir_read_leaf(struct inode *inode, struct dir_context *ctx,
- int *copied, unsigned *depth,
- u64 leaf_no)
- {
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_sbd *sdp = GFS2_SB(inode);
- struct buffer_head *bh;
- struct gfs2_leaf *lf;
- unsigned entries = 0, entries2 = 0;
- unsigned leaves = 0, leaf = 0, offset, sort_offset;
- struct gfs2_dirent **darr, *dent;
- struct dirent_gather g;
- struct buffer_head **larr;
- int error, i, need_sort = 0, sort_id;
- u64 lfn = leaf_no;
- do {
- error = get_leaf(ip, lfn, &bh);
- if (error)
- goto out;
- lf = (struct gfs2_leaf *)bh->b_data;
- if (leaves == 0)
- *depth = be16_to_cpu(lf->lf_depth);
- entries += be16_to_cpu(lf->lf_entries);
- leaves++;
- lfn = be64_to_cpu(lf->lf_next);
- brelse(bh);
- } while(lfn);
- if (*depth < GFS2_DIR_MAX_DEPTH || !sdp->sd_args.ar_loccookie) {
- need_sort = 1;
- sort_offset = 0;
- }
- if (!entries)
- return 0;
- error = -ENOMEM;
- /*
- * The extra 99 entries are not normally used, but are a buffer
- * zone in case the number of entries in the leaf is corrupt.
- * 99 is the maximum number of entries that can fit in a single
- * leaf block.
- */
- larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
- if (!larr)
- goto out;
- darr = (struct gfs2_dirent **)(larr + leaves);
- g.pdent = (const struct gfs2_dirent **)darr;
- g.offset = 0;
- lfn = leaf_no;
- do {
- error = get_leaf(ip, lfn, &bh);
- if (error)
- goto out_free;
- lf = (struct gfs2_leaf *)bh->b_data;
- lfn = be64_to_cpu(lf->lf_next);
- if (lf->lf_entries) {
- offset = g.offset;
- entries2 += be16_to_cpu(lf->lf_entries);
- dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
- gfs2_dirent_gather, NULL, &g);
- error = PTR_ERR(dent);
- if (IS_ERR(dent))
- goto out_free;
- if (entries2 != g.offset) {
- fs_warn(sdp, "Number of entries corrupt in dir "
- "leaf %llu, entries2 (%u) != "
- "g.offset (%u)\n",
- (unsigned long long)bh->b_blocknr,
- entries2, g.offset);
- gfs2_consist_inode(ip);
- error = -EIO;
- goto out_free;
- }
- error = 0;
- sort_id = gfs2_set_cookies(sdp, bh, leaf, &darr[offset],
- be16_to_cpu(lf->lf_entries));
- if (!need_sort && sort_id >= 0) {
- need_sort = 1;
- sort_offset = offset + sort_id;
- }
- larr[leaf++] = bh;
- } else {
- larr[leaf++] = NULL;
- brelse(bh);
- }
- } while(lfn);
- BUG_ON(entries2 != entries);
- error = do_filldir_main(ip, ctx, darr, entries, need_sort ?
- sort_offset : entries, copied);
- out_free:
- for(i = 0; i < leaf; i++)
- if (larr[i])
- brelse(larr[i]);
- kvfree(larr);
- out:
- return error;
- }
- /**
- * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks.
- *
- * Note: we can't calculate each index like dir_e_read can because we don't
- * have the leaf, and therefore we don't have the depth, and therefore we
- * don't have the length. So we have to just read enough ahead to make up
- * for the loss of information.
- */
- static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index,
- struct file_ra_state *f_ra)
- {
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_glock *gl = ip->i_gl;
- struct buffer_head *bh;
- u64 blocknr = 0, last;
- unsigned count;
- /* First check if we've already read-ahead for the whole range. */
- if (index + MAX_RA_BLOCKS < f_ra->start)
- return;
- f_ra->start = max((pgoff_t)index, f_ra->start);
- for (count = 0; count < MAX_RA_BLOCKS; count++) {
- if (f_ra->start >= hsize) /* if exceeded the hash table */
- break;
- last = blocknr;
- blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]);
- f_ra->start++;
- if (blocknr == last)
- continue;
- bh = gfs2_getbuf(gl, blocknr, 1);
- if (trylock_buffer(bh)) {
- if (buffer_uptodate(bh)) {
- unlock_buffer(bh);
- brelse(bh);
- continue;
- }
- bh->b_end_io = end_buffer_read_sync;
- submit_bh(REQ_OP_READ,
- REQ_RAHEAD | REQ_META | REQ_PRIO,
- bh);
- continue;
- }
- brelse(bh);
- }
- }
- /**
- * dir_e_read - Reads the entries from a directory into a filldir buffer
- * @dip: dinode pointer
- * @ctx: actor to feed the entries to
- *
- * Returns: errno
- */
- static int dir_e_read(struct inode *inode, struct dir_context *ctx,
- struct file_ra_state *f_ra)
- {
- struct gfs2_inode *dip = GFS2_I(inode);
- u32 hsize, len = 0;
- u32 hash, index;
- __be64 *lp;
- int copied = 0;
- int error = 0;
- unsigned depth = 0;
- hsize = BIT(dip->i_depth);
- hash = gfs2_dir_offset2hash(ctx->pos);
- index = hash >> (32 - dip->i_depth);
- if (dip->i_hash_cache == NULL)
- f_ra->start = 0;
- lp = gfs2_dir_get_hash_table(dip);
- if (IS_ERR(lp))
- return PTR_ERR(lp);
- gfs2_dir_readahead(inode, hsize, index, f_ra);
- while (index < hsize) {
- error = gfs2_dir_read_leaf(inode, ctx,
- &copied, &depth,
- be64_to_cpu(lp[index]));
- if (error)
- break;
- len = BIT(dip->i_depth - depth);
- index = (index & ~(len - 1)) + len;
- }
- if (error > 0)
- error = 0;
- return error;
- }
- int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
- struct file_ra_state *f_ra)
- {
- struct gfs2_inode *dip = GFS2_I(inode);
- struct gfs2_sbd *sdp = GFS2_SB(inode);
- struct dirent_gather g;
- struct gfs2_dirent **darr, *dent;
- struct buffer_head *dibh;
- int copied = 0;
- int error;
- if (!dip->i_entries)
- return 0;
- if (dip->i_diskflags & GFS2_DIF_EXHASH)
- return dir_e_read(inode, ctx, f_ra);
- if (!gfs2_is_stuffed(dip)) {
- gfs2_consist_inode(dip);
- return -EIO;
- }
- error = gfs2_meta_inode_buffer(dip, &dibh);
- if (error)
- return error;
- error = -ENOMEM;
- /* 96 is max number of dirents which can be stuffed into an inode */
- darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
- if (darr) {
- g.pdent = (const struct gfs2_dirent **)darr;
- g.offset = 0;
- dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
- gfs2_dirent_gather, NULL, &g);
- if (IS_ERR(dent)) {
- error = PTR_ERR(dent);
- goto out;
- }
- if (dip->i_entries != g.offset) {
- fs_warn(sdp, "Number of entries corrupt in dir %llu, "
- "ip->i_entries (%u) != g.offset (%u)\n",
- (unsigned long long)dip->i_no_addr,
- dip->i_entries,
- g.offset);
- gfs2_consist_inode(dip);
- error = -EIO;
- goto out;
- }
- gfs2_set_cookies(sdp, dibh, 0, darr, dip->i_entries);
- error = do_filldir_main(dip, ctx, darr,
- dip->i_entries, 0, &copied);
- out:
- kfree(darr);
- }
- if (error > 0)
- error = 0;
- brelse(dibh);
- return error;
- }
- /**
- * gfs2_dir_search - Search a directory
- * @dip: The GFS2 dir inode
- * @name: The name we are looking up
- * @fail_on_exist: Fail if the name exists rather than looking it up
- *
- * This routine searches a directory for a file or another directory.
- * Assumes a glock is held on dip.
- *
- * Returns: errno
- */
- struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name,
- bool fail_on_exist)
- {
- struct buffer_head *bh;
- struct gfs2_dirent *dent;
- u64 addr, formal_ino;
- u16 dtype;
- dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
- if (dent) {
- struct inode *inode;
- u16 rahead;
- if (IS_ERR(dent))
- return ERR_CAST(dent);
- dtype = be16_to_cpu(dent->de_type);
- rahead = be16_to_cpu(dent->de_rahead);
- addr = be64_to_cpu(dent->de_inum.no_addr);
- formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino);
- brelse(bh);
- if (fail_on_exist)
- return ERR_PTR(-EEXIST);
- inode = gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino,
- GFS2_BLKST_FREE /* ignore */);
- if (!IS_ERR(inode))
- GFS2_I(inode)->i_rahead = rahead;
- return inode;
- }
- return ERR_PTR(-ENOENT);
- }
- int gfs2_dir_check(struct inode *dir, const struct qstr *name,
- const struct gfs2_inode *ip)
- {
- struct buffer_head *bh;
- struct gfs2_dirent *dent;
- int ret = -ENOENT;
- dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
- if (dent) {
- if (IS_ERR(dent))
- return PTR_ERR(dent);
- if (ip) {
- if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
- goto out;
- if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
- ip->i_no_formal_ino)
- goto out;
- if (unlikely(IF2DT(ip->i_inode.i_mode) !=
- be16_to_cpu(dent->de_type))) {
- gfs2_consist_inode(GFS2_I(dir));
- ret = -EIO;
- goto out;
- }
- }
- ret = 0;
- out:
- brelse(bh);
- }
- return ret;
- }
- /**
- * dir_new_leaf - Add a new leaf onto hash chain
- * @inode: The directory
- * @name: The name we are adding
- *
- * This adds a new dir leaf onto an existing leaf when there is not
- * enough space to add a new dir entry. This is a last resort after
- * we've expanded the hash table to max size and also split existing
- * leaf blocks, so it will only occur for very large directories.
- *
- * The dist parameter is set to 1 for leaf blocks directly attached
- * to the hash table, 2 for one layer of indirection, 3 for two layers
- * etc. We are thus able to tell the difference between an old leaf
- * with dist set to zero (i.e. "don't know") and a new one where we
- * set this information for debug/fsck purposes.
- *
- * Returns: 0 on success, or -ve on error
- */
- static int dir_new_leaf(struct inode *inode, const struct qstr *name)
- {
- struct buffer_head *bh, *obh;
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_leaf *leaf, *oleaf;
- u32 dist = 1;
- int error;
- u32 index;
- u64 bn;
- index = name->hash >> (32 - ip->i_depth);
- error = get_first_leaf(ip, index, &obh);
- if (error)
- return error;
- do {
- dist++;
- oleaf = (struct gfs2_leaf *)obh->b_data;
- bn = be64_to_cpu(oleaf->lf_next);
- if (!bn)
- break;
- brelse(obh);
- error = get_leaf(ip, bn, &obh);
- if (error)
- return error;
- } while(1);
- gfs2_trans_add_meta(ip->i_gl, obh);
- leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
- if (!leaf) {
- brelse(obh);
- return -ENOSPC;
- }
- leaf->lf_dist = cpu_to_be32(dist);
- oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
- brelse(bh);
- brelse(obh);
- error = gfs2_meta_inode_buffer(ip, &bh);
- if (error)
- return error;
- gfs2_trans_add_meta(ip->i_gl, bh);
- gfs2_add_inode_blocks(&ip->i_inode, 1);
- gfs2_dinode_out(ip, bh->b_data);
- brelse(bh);
- return 0;
- }
- static u16 gfs2_inode_ra_len(const struct gfs2_inode *ip)
- {
- u64 where = ip->i_no_addr + 1;
- if (ip->i_eattr == where)
- return 1;
- return 0;
- }
- /**
- * gfs2_dir_add - Add new filename into directory
- * @inode: The directory inode
- * @name: The new name
- * @nip: The GFS2 inode to be linked in to the directory
- * @da: The directory addition info
- *
- * If the call to gfs2_diradd_alloc_required resulted in there being
- * no need to allocate any new directory blocks, then it will contain
- * a pointer to the directory entry and the bh in which it resides. We
- * can use that without having to repeat the search. If there was no
- * free space, then we must now create more space.
- *
- * Returns: 0 on success, error code on failure
- */
- int gfs2_dir_add(struct inode *inode, const struct qstr *name,
- const struct gfs2_inode *nip, struct gfs2_diradd *da)
- {
- struct gfs2_inode *ip = GFS2_I(inode);
- struct buffer_head *bh = da->bh;
- struct gfs2_dirent *dent = da->dent;
- struct timespec tv;
- struct gfs2_leaf *leaf;
- int error;
- while(1) {
- if (da->bh == NULL) {
- dent = gfs2_dirent_search(inode, name,
- gfs2_dirent_find_space, &bh);
- }
- if (dent) {
- if (IS_ERR(dent))
- return PTR_ERR(dent);
- dent = gfs2_init_dirent(inode, dent, name, bh);
- gfs2_inum_out(nip, dent);
- dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
- dent->de_rahead = cpu_to_be16(gfs2_inode_ra_len(nip));
- tv = current_time(&ip->i_inode);
- if (ip->i_diskflags & GFS2_DIF_EXHASH) {
- leaf = (struct gfs2_leaf *)bh->b_data;
- be16_add_cpu(&leaf->lf_entries, 1);
- leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
- leaf->lf_sec = cpu_to_be64(tv.tv_sec);
- }
- da->dent = NULL;
- da->bh = NULL;
- brelse(bh);
- ip->i_entries++;
- ip->i_inode.i_mtime = ip->i_inode.i_ctime = tv;
- if (S_ISDIR(nip->i_inode.i_mode))
- inc_nlink(&ip->i_inode);
- mark_inode_dirty(inode);
- error = 0;
- break;
- }
- if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
- error = dir_make_exhash(inode);
- if (error)
- break;
- continue;
- }
- error = dir_split_leaf(inode, name);
- if (error == 0)
- continue;
- if (error < 0)
- break;
- if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
- error = dir_double_exhash(ip);
- if (error)
- break;
- error = dir_split_leaf(inode, name);
- if (error < 0)
- break;
- if (error == 0)
- continue;
- }
- error = dir_new_leaf(inode, name);
- if (!error)
- continue;
- error = -ENOSPC;
- break;
- }
- return error;
- }
- /**
- * gfs2_dir_del - Delete a directory entry
- * @dip: The GFS2 inode
- * @filename: The filename
- *
- * Returns: 0 on success, error code on failure
- */
- int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
- {
- const struct qstr *name = &dentry->d_name;
- struct gfs2_dirent *dent, *prev = NULL;
- struct buffer_head *bh;
- struct timespec tv = current_time(&dip->i_inode);
- /* Returns _either_ the entry (if its first in block) or the
- previous entry otherwise */
- dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
- if (!dent) {
- gfs2_consist_inode(dip);
- return -EIO;
- }
- if (IS_ERR(dent)) {
- gfs2_consist_inode(dip);
- return PTR_ERR(dent);
- }
- /* If not first in block, adjust pointers accordingly */
- if (gfs2_dirent_find(dent, name, NULL) == 0) {
- prev = dent;
- dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
- }
- dirent_del(dip, bh, prev, dent);
- if (dip->i_diskflags & GFS2_DIF_EXHASH) {
- struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
- u16 entries = be16_to_cpu(leaf->lf_entries);
- if (!entries)
- gfs2_consist_inode(dip);
- leaf->lf_entries = cpu_to_be16(--entries);
- leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
- leaf->lf_sec = cpu_to_be64(tv.tv_sec);
- }
- brelse(bh);
- if (!dip->i_entries)
- gfs2_consist_inode(dip);
- dip->i_entries--;
- dip->i_inode.i_mtime = dip->i_inode.i_ctime = tv;
- if (d_is_dir(dentry))
- drop_nlink(&dip->i_inode);
- mark_inode_dirty(&dip->i_inode);
- return 0;
- }
- /**
- * gfs2_dir_mvino - Change inode number of directory entry
- * @dip: The GFS2 inode
- * @filename:
- * @new_inode:
- *
- * This routine changes the inode number of a directory entry. It's used
- * by rename to change ".." when a directory is moved.
- * Assumes a glock is held on dvp.
- *
- * Returns: errno
- */
- int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
- const struct gfs2_inode *nip, unsigned int new_type)
- {
- struct buffer_head *bh;
- struct gfs2_dirent *dent;
- int error;
- dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
- if (!dent) {
- gfs2_consist_inode(dip);
- return -EIO;
- }
- if (IS_ERR(dent))
- return PTR_ERR(dent);
- gfs2_trans_add_meta(dip->i_gl, bh);
- gfs2_inum_out(nip, dent);
- dent->de_type = cpu_to_be16(new_type);
- if (dip->i_diskflags & GFS2_DIF_EXHASH) {
- brelse(bh);
- error = gfs2_meta_inode_buffer(dip, &bh);
- if (error)
- return error;
- gfs2_trans_add_meta(dip->i_gl, bh);
- }
- dip->i_inode.i_mtime = dip->i_inode.i_ctime = current_time(&dip->i_inode);
- gfs2_dinode_out(dip, bh->b_data);
- brelse(bh);
- return 0;
- }
- /**
- * leaf_dealloc - Deallocate a directory leaf
- * @dip: the directory
- * @index: the hash table offset in the directory
- * @len: the number of pointers to this leaf
- * @leaf_no: the leaf number
- * @leaf_bh: buffer_head for the starting leaf
- * last_dealloc: 1 if this is the final dealloc for the leaf, else 0
- *
- * Returns: errno
- */
- static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
- u64 leaf_no, struct buffer_head *leaf_bh,
- int last_dealloc)
- {
- struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
- struct gfs2_leaf *tmp_leaf;
- struct gfs2_rgrp_list rlist;
- struct buffer_head *bh, *dibh;
- u64 blk, nblk;
- unsigned int rg_blocks = 0, l_blocks = 0;
- char *ht;
- unsigned int x, size = len * sizeof(u64);
- int error;
- error = gfs2_rindex_update(sdp);
- if (error)
- return error;
- memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
- ht = kzalloc(size, GFP_NOFS | __GFP_NOWARN);
- if (ht == NULL)
- ht = __vmalloc(size, GFP_NOFS | __GFP_NOWARN | __GFP_ZERO,
- PAGE_KERNEL);
- if (!ht)
- return -ENOMEM;
- error = gfs2_quota_hold(dip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
- if (error)
- goto out;
- /* Count the number of leaves */
- bh = leaf_bh;
- for (blk = leaf_no; blk; blk = nblk) {
- if (blk != leaf_no) {
- error = get_leaf(dip, blk, &bh);
- if (error)
- goto out_rlist;
- }
- tmp_leaf = (struct gfs2_leaf *)bh->b_data;
- nblk = be64_to_cpu(tmp_leaf->lf_next);
- if (blk != leaf_no)
- brelse(bh);
- gfs2_rlist_add(dip, &rlist, blk);
- l_blocks++;
- }
- gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
- for (x = 0; x < rlist.rl_rgrps; x++) {
- struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(rlist.rl_ghs[x].gh_gl);
- rg_blocks += rgd->rd_length;
- }
- error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
- if (error)
- goto out_rlist;
- error = gfs2_trans_begin(sdp,
- rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
- RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
- if (error)
- goto out_rg_gunlock;
- bh = leaf_bh;
- for (blk = leaf_no; blk; blk = nblk) {
- if (blk != leaf_no) {
- error = get_leaf(dip, blk, &bh);
- if (error)
- goto out_end_trans;
- }
- tmp_leaf = (struct gfs2_leaf *)bh->b_data;
- nblk = be64_to_cpu(tmp_leaf->lf_next);
- if (blk != leaf_no)
- brelse(bh);
- gfs2_free_meta(dip, blk, 1);
- gfs2_add_inode_blocks(&dip->i_inode, -1);
- }
- error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
- if (error != size) {
- if (error >= 0)
- error = -EIO;
- goto out_end_trans;
- }
- error = gfs2_meta_inode_buffer(dip, &dibh);
- if (error)
- goto out_end_trans;
- gfs2_trans_add_meta(dip->i_gl, dibh);
- /* On the last dealloc, make this a regular file in case we crash.
- (We don't want to free these blocks a second time.) */
- if (last_dealloc)
- dip->i_inode.i_mode = S_IFREG;
- gfs2_dinode_out(dip, dibh->b_data);
- brelse(dibh);
- out_end_trans:
- gfs2_trans_end(sdp);
- out_rg_gunlock:
- gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
- out_rlist:
- gfs2_rlist_free(&rlist);
- gfs2_quota_unhold(dip);
- out:
- kvfree(ht);
- return error;
- }
- /**
- * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
- * @dip: the directory
- *
- * Dealloc all on-disk directory leaves to FREEMETA state
- * Change on-disk inode type to "regular file"
- *
- * Returns: errno
- */
- int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
- {
- struct buffer_head *bh;
- struct gfs2_leaf *leaf;
- u32 hsize, len;
- u32 index = 0, next_index;
- __be64 *lp;
- u64 leaf_no;
- int error = 0, last;
- hsize = BIT(dip->i_depth);
- lp = gfs2_dir_get_hash_table(dip);
- if (IS_ERR(lp))
- return PTR_ERR(lp);
- while (index < hsize) {
- leaf_no = be64_to_cpu(lp[index]);
- if (leaf_no) {
- error = get_leaf(dip, leaf_no, &bh);
- if (error)
- goto out;
- leaf = (struct gfs2_leaf *)bh->b_data;
- len = BIT(dip->i_depth - be16_to_cpu(leaf->lf_depth));
- next_index = (index & ~(len - 1)) + len;
- last = ((next_index >= hsize) ? 1 : 0);
- error = leaf_dealloc(dip, index, len, leaf_no, bh,
- last);
- brelse(bh);
- if (error)
- goto out;
- index = next_index;
- } else
- index++;
- }
- if (index != hsize) {
- gfs2_consist_inode(dip);
- error = -EIO;
- }
- out:
- return error;
- }
- /**
- * gfs2_diradd_alloc_required - find if adding entry will require an allocation
- * @ip: the file being written to
- * @filname: the filename that's going to be added
- * @da: The structure to return dir alloc info
- *
- * Returns: 0 if ok, -ve on error
- */
- int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name,
- struct gfs2_diradd *da)
- {
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_sbd *sdp = GFS2_SB(inode);
- const unsigned int extra = sizeof(struct gfs2_dinode) - sizeof(struct gfs2_leaf);
- struct gfs2_dirent *dent;
- struct buffer_head *bh;
- da->nr_blocks = 0;
- da->bh = NULL;
- da->dent = NULL;
- dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
- if (!dent) {
- da->nr_blocks = sdp->sd_max_dirres;
- if (!(ip->i_diskflags & GFS2_DIF_EXHASH) &&
- (GFS2_DIRENT_SIZE(name->len) < extra))
- da->nr_blocks = 1;
- return 0;
- }
- if (IS_ERR(dent))
- return PTR_ERR(dent);
- if (da->save_loc) {
- da->bh = bh;
- da->dent = dent;
- } else {
- brelse(bh);
- }
- return 0;
- }