cmservice.o \
dir.o \
dir_edit.o \
+ dir_search.o \
dir_silly.o \
dynroot.o \
file.o \
struct afs_lookup_cookie {
struct dir_context ctx;
struct qstr name;
- bool found;
- bool one_only;
unsigned short nr_fids;
struct afs_fid fids[50];
};
* Read the directory into a folio_queue buffer in one go, scrubbing the
* previous contents. We return -ESTALE if the caller needs to call us again.
*/
-static ssize_t afs_read_dir(struct afs_vnode *dvnode, struct file *file)
+ssize_t afs_read_dir(struct afs_vnode *dvnode, struct file *file)
__acquires(&dvnode->validate_lock)
{
ssize_t ret;
BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
- if (cookie->found) {
- if (cookie->nr_fids < 50) {
- cookie->fids[cookie->nr_fids].vnode = ino;
- cookie->fids[cookie->nr_fids].unique = dtype;
- cookie->nr_fids++;
- }
- } else if (cookie->name.len == nlen &&
- memcmp(cookie->name.name, name, nlen) == 0) {
- cookie->fids[1].vnode = ino;
- cookie->fids[1].unique = dtype;
- cookie->found = 1;
- if (cookie->one_only)
- return false;
+ if (cookie->nr_fids < 50) {
+ cookie->fids[cookie->nr_fids].vnode = ino;
+ cookie->fids[cookie->nr_fids].unique = dtype;
+ cookie->nr_fids++;
}
return cookie->nr_fids < 50;
struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode;
struct inode *inode = NULL, *ti;
afs_dataversion_t data_version = READ_ONCE(dvnode->status.data_version);
+ bool supports_ibulk;
long ret;
int i;
cookie->nr_fids = 2; /* slot 1 is saved for the fid we actually want
* and slot 0 for the directory */
- if (!afs_server_supports_ibulk(dvnode))
- cookie->one_only = true;
-
- /* search the directory */
- ret = afs_dir_iterate(dir, &cookie->ctx, NULL, &data_version);
+ /* Search the directory for the named entry using the hash table... */
+ ret = afs_dir_search(dvnode, &dentry->d_name, &cookie->fids[1], &data_version);
if (ret < 0)
goto out;
- dentry->d_fsdata = (void *)(unsigned long)data_version;
+ supports_ibulk = afs_server_supports_ibulk(dvnode);
+ if (supports_ibulk) {
+ /* ...then scan linearly from that point for entries to lookup-ahead. */
+ cookie->ctx.pos = (ret + 1) * AFS_DIR_DIRENT_SIZE;
+ afs_dir_iterate(dir, &cookie->ctx, NULL, &data_version);
+ }
- ret = -ENOENT;
- if (!cookie->found)
- goto out;
+ dentry->d_fsdata = (void *)(unsigned long)data_version;
/* Check to see if we already have an inode for the primary fid. */
inode = ilookup5(dir->i_sb, cookie->fids[1].vnode,
* the whole operation.
*/
afs_op_set_error(op, -ENOTSUPP);
- if (!cookie->one_only) {
+ if (supports_ibulk) {
op->ops = &afs_inline_bulk_status_operation;
afs_begin_vnode_operation(op);
afs_wait_for_operation(op);
union afs_xdr_dir_block *meta, *block;
union afs_xdr_dirent *de;
struct afs_dir_iter iter = { .dvnode = vnode };
- unsigned int need_slots, nr_blocks, b;
+ unsigned int nr_blocks, b, entry;
loff_t i_size;
int slot;
return;
/* Work out how many slots we're going to need. */
- need_slots = afs_dir_calc_slots(name->len);
+ iter.nr_slots = afs_dir_calc_slots(name->len);
if (i_size == 0)
goto new_directory;
/* Lower dir blocks have a counter in the header we can check. */
if (b < AFS_DIR_BLOCKS_WITH_CTR &&
- meta->meta.alloc_ctrs[b] < need_slots)
+ meta->meta.alloc_ctrs[b] < iter.nr_slots)
continue;
block = afs_dir_get_block(&iter, b);
/* We need to try and find one or more consecutive slots to
* hold the entry.
*/
- slot = afs_find_contig_bits(block, need_slots);
+ slot = afs_find_contig_bits(block, iter.nr_slots);
if (slot >= 0) {
_debug("slot %u", slot);
goto found_space;
de->u.name[name->len] = 0;
/* Adjust the bitmap. */
- afs_set_contig_bits(block, slot, need_slots);
- kunmap_local(block);
+ afs_set_contig_bits(block, slot, iter.nr_slots);
/* Adjust the allocation counter. */
if (b < AFS_DIR_BLOCKS_WITH_CTR)
- meta->meta.alloc_ctrs[b] -= need_slots;
+ meta->meta.alloc_ctrs[b] -= iter.nr_slots;
+
+ /* Adjust the hash chain. */
+ entry = b * AFS_DIR_SLOTS_PER_BLOCK + slot;
+ iter.bucket = afs_dir_hash_name(name);
+ de->u.hash_next = meta->meta.hashtable[iter.bucket];
+ meta->meta.hashtable[iter.bucket] = htons(entry);
+ kunmap_local(block);
inode_inc_iversion_raw(&vnode->netfs.inode);
afs_stat_v(vnode, n_dir_cr);
void afs_edit_dir_remove(struct afs_vnode *vnode,
struct qstr *name, enum afs_edit_dir_reason why)
{
- union afs_xdr_dir_block *meta, *block;
- union afs_xdr_dirent *de;
+ union afs_xdr_dir_block *meta, *block, *pblock;
+ union afs_xdr_dirent *de, *pde;
struct afs_dir_iter iter = { .dvnode = vnode };
- unsigned int need_slots, nr_blocks, b;
+ struct afs_fid fid;
+ unsigned int b, slot, entry;
loff_t i_size;
- int slot;
+ __be16 next;
+ int found;
_enter(",,{%d,%s},", name->len, name->name);
afs_invalidate_dir(vnode, afs_dir_invalid_edit_rem_bad_size);
return;
}
- nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
- meta = afs_dir_get_block(&iter, 0);
- if (!meta)
+ if (!afs_dir_init_iter(&iter, name))
return;
- /* Work out how many slots we're going to discard. */
- need_slots = afs_dir_calc_slots(name->len);
-
- /* Find a block that has sufficient slots available. Each folio
- * contains two or more directory blocks.
- */
- for (b = 0; b < nr_blocks; b++) {
- block = afs_dir_get_block(&iter, b);
- if (!block)
- goto error;
-
- /* Abandon the edit if we got a callback break. */
- if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
- goto already_invalidated;
-
- if (b > AFS_DIR_BLOCKS_WITH_CTR ||
- meta->meta.alloc_ctrs[b] <= AFS_DIR_SLOTS_PER_BLOCK - 1 - need_slots) {
- slot = afs_dir_scan_block(block, name, b);
- if (slot >= 0)
- goto found_dirent;
- }
+ meta = afs_dir_find_block(&iter, 0);
+ if (!meta)
+ return;
- kunmap_local(block);
+ /* Find the entry in the blob. */
+ found = afs_dir_search_bucket(&iter, name, &fid);
+ if (found < 0) {
+ /* Didn't find the dirent to clobber. Re-download. */
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_noent,
+ 0, 0, 0, 0, name->name);
+ afs_invalidate_dir(vnode, afs_dir_invalid_edit_rem_wrong_name);
+ goto out_unmap;
}
- /* Didn't find the dirent to clobber. Download the directory again. */
- trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_noent,
- 0, 0, 0, 0, name->name);
- afs_invalidate_dir(vnode, afs_dir_invalid_edit_rem_wrong_name);
- goto out_unmap;
+ entry = found;
+ b = entry / AFS_DIR_SLOTS_PER_BLOCK;
+ slot = entry % AFS_DIR_SLOTS_PER_BLOCK;
-found_dirent:
+ block = afs_dir_find_block(&iter, b);
+ if (!block)
+ goto error;
+ if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+ goto already_invalidated;
+
+ /* Check and clear the entry. */
de = &block->dirents[slot];
+ if (de->u.valid != 1)
+ goto error_unmap;
trace_afs_edit_dir(vnode, why, afs_edit_dir_delete, b, slot,
ntohl(de->u.vnode), ntohl(de->u.unique),
name->name);
- memset(de, 0, sizeof(*de) * need_slots);
-
/* Adjust the bitmap. */
- afs_clear_contig_bits(block, slot, need_slots);
- kunmap_local(block);
+ afs_clear_contig_bits(block, slot, iter.nr_slots);
/* Adjust the allocation counter. */
if (b < AFS_DIR_BLOCKS_WITH_CTR)
- meta->meta.alloc_ctrs[b] += need_slots;
+ meta->meta.alloc_ctrs[b] += iter.nr_slots;
+
+ /* Clear the constituent entries. */
+ next = de->u.hash_next;
+ memset(de, 0, sizeof(*de) * iter.nr_slots);
+ kunmap_local(block);
+
+ /* Adjust the hash chain: if iter->prev_entry is 0, the hashtable head
+ * index is previous; otherwise it's slot number of the previous entry.
+ */
+ if (!iter.prev_entry) {
+ __be16 prev_next = meta->meta.hashtable[iter.bucket];
+
+ if (unlikely(prev_next != htons(entry))) {
+ pr_warn("%llx:%llx:%x: not head of chain b=%x p=%x,%x e=%x %*s",
+ vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
+ iter.bucket, iter.prev_entry, prev_next, entry,
+ name->len, name->name);
+ goto error;
+ }
+ meta->meta.hashtable[iter.bucket] = next;
+ } else {
+ unsigned int pb = iter.prev_entry / AFS_DIR_SLOTS_PER_BLOCK;
+ unsigned int ps = iter.prev_entry % AFS_DIR_SLOTS_PER_BLOCK;
+ __be16 prev_next;
+
+ pblock = afs_dir_find_block(&iter, pb);
+ if (!pblock)
+ goto error;
+ pde = &pblock->dirents[ps];
+ prev_next = pde->u.hash_next;
+ if (prev_next != htons(entry)) {
+ kunmap_local(pblock);
+ pr_warn("%llx:%llx:%x: not prev in chain b=%x p=%x,%x e=%x %*s",
+ vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
+ iter.bucket, iter.prev_entry, prev_next, entry,
+ name->len, name->name);
+ goto error;
+ }
+ pde->u.hash_next = next;
+ kunmap_local(pblock);
+ }
netfs_single_mark_inode_dirty(&vnode->netfs.inode);
0, 0, 0, 0, name->name);
goto out_unmap;
+error_unmap:
+ kunmap_local(block);
error:
trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_error,
0, 0, 0, 0, name->name);
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Search a directory's hash table.
+ *
+ * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * https://tools.ietf.org/html/draft-keiser-afs3-directory-object-00
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/iversion.h>
+#include "internal.h"
+#include "afs_fs.h"
+#include "xdr_fs.h"
+
+/*
+ * Calculate the name hash.
+ */
+unsigned int afs_dir_hash_name(const struct qstr *name)
+{
+ const unsigned char *p = name->name;
+ unsigned int hash = 0, i;
+ int bucket;
+
+ for (i = 0; i < name->len; i++)
+ hash = (hash * 173) + p[i];
+ bucket = hash & (AFS_DIR_HASHTBL_SIZE - 1);
+ if (hash > INT_MAX) {
+ bucket = AFS_DIR_HASHTBL_SIZE - bucket;
+ bucket &= (AFS_DIR_HASHTBL_SIZE - 1);
+ }
+ return bucket;
+}
+
+/*
+ * Reset a directory iterator.
+ */
+static bool afs_dir_reset_iter(struct afs_dir_iter *iter)
+{
+ unsigned long long i_size = i_size_read(&iter->dvnode->netfs.inode);
+ unsigned int nblocks;
+
+ /* Work out the maximum number of steps we can take. */
+ nblocks = umin(i_size / AFS_DIR_BLOCK_SIZE, AFS_DIR_MAX_BLOCKS);
+ if (!nblocks)
+ return false;
+ iter->loop_check = nblocks * (AFS_DIR_SLOTS_PER_BLOCK - AFS_DIR_RESV_BLOCKS);
+ iter->prev_entry = 0; /* Hash head is previous */
+ return true;
+}
+
+/*
+ * Initialise a directory iterator for looking up a name.
+ */
+bool afs_dir_init_iter(struct afs_dir_iter *iter, const struct qstr *name)
+{
+ iter->nr_slots = afs_dir_calc_slots(name->len);
+ iter->bucket = afs_dir_hash_name(name);
+ return afs_dir_reset_iter(iter);
+}
+
+/*
+ * Get a specific block.
+ */
+union afs_xdr_dir_block *afs_dir_find_block(struct afs_dir_iter *iter, size_t block)
+{
+ struct folio_queue *fq = iter->fq;
+ struct afs_vnode *dvnode = iter->dvnode;
+ struct folio *folio;
+ size_t blpos = block * AFS_DIR_BLOCK_SIZE;
+ size_t blend = (block + 1) * AFS_DIR_BLOCK_SIZE, fpos = iter->fpos;
+ int slot = iter->fq_slot;
+
+ _enter("%zx,%d", block, slot);
+
+ if (iter->block) {
+ kunmap_local(iter->block);
+ iter->block = NULL;
+ }
+
+ if (dvnode->directory_size < blend)
+ goto fail;
+
+ if (!fq || blpos < fpos) {
+ fq = dvnode->directory;
+ slot = 0;
+ fpos = 0;
+ }
+
+ /* Search the folio queue for the folio containing the block... */
+ for (; fq; fq = fq->next) {
+ for (; slot < folioq_count(fq); slot++) {
+ size_t fsize = folioq_folio_size(fq, slot);
+
+ if (blend <= fpos + fsize) {
+ /* ... and then return the mapped block. */
+ folio = folioq_folio(fq, slot);
+ if (WARN_ON_ONCE(folio_pos(folio) != fpos))
+ goto fail;
+ iter->fq = fq;
+ iter->fq_slot = slot;
+ iter->fpos = fpos;
+ iter->block = kmap_local_folio(folio, blpos - fpos);
+ return iter->block;
+ }
+ fpos += fsize;
+ }
+ slot = 0;
+ }
+
+fail:
+ iter->fq = NULL;
+ iter->fq_slot = 0;
+ afs_invalidate_dir(dvnode, afs_dir_invalid_edit_get_block);
+ return NULL;
+}
+
+/*
+ * Search through a directory bucket.
+ */
+int afs_dir_search_bucket(struct afs_dir_iter *iter, const struct qstr *name,
+ struct afs_fid *_fid)
+{
+ const union afs_xdr_dir_block *meta;
+ unsigned int entry;
+ int ret = -ESTALE;
+
+ meta = afs_dir_find_block(iter, 0);
+ if (!meta)
+ return -ESTALE;
+
+ entry = ntohs(meta->meta.hashtable[iter->bucket & (AFS_DIR_HASHTBL_SIZE - 1)]);
+ _enter("%x,%x", iter->bucket, entry);
+
+ while (entry) {
+ const union afs_xdr_dir_block *block;
+ const union afs_xdr_dirent *dire;
+ unsigned int blnum = entry / AFS_DIR_SLOTS_PER_BLOCK;
+ unsigned int slot = entry % AFS_DIR_SLOTS_PER_BLOCK;
+ unsigned int resv = (blnum == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
+
+ _debug("search %x", entry);
+
+ if (slot < resv) {
+ kdebug("slot out of range h=%x rs=%2x sl=%2x-%2x",
+ iter->bucket, resv, slot, slot + iter->nr_slots - 1);
+ goto bad;
+ }
+
+ block = afs_dir_find_block(iter, blnum);
+ if (!block)
+ goto bad;
+ dire = &block->dirents[slot];
+
+ if (slot + iter->nr_slots <= AFS_DIR_SLOTS_PER_BLOCK &&
+ memcmp(dire->u.name, name->name, name->len) == 0 &&
+ dire->u.name[name->len] == '\0') {
+ _fid->vnode = ntohl(dire->u.vnode);
+ _fid->unique = ntohl(dire->u.unique);
+ ret = entry;
+ goto found;
+ }
+
+ iter->prev_entry = entry;
+ entry = ntohs(dire->u.hash_next);
+ if (!--iter->loop_check) {
+ kdebug("dir chain loop h=%x", iter->bucket);
+ goto bad;
+ }
+ }
+
+ ret = -ENOENT;
+found:
+ if (iter->block) {
+ kunmap_local(iter->block);
+ iter->block = NULL;
+ }
+
+bad:
+ if (ret == -ESTALE)
+ afs_invalidate_dir(iter->dvnode, afs_dir_invalid_iter_stale);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Search the appropriate hash chain in the contents of an AFS directory.
+ */
+int afs_dir_search(struct afs_vnode *dvnode, struct qstr *name,
+ struct afs_fid *_fid, afs_dataversion_t *_dir_version)
+{
+ struct afs_dir_iter iter = { .dvnode = dvnode, };
+ int ret, retry_limit = 3;
+
+ _enter("{%lu},,,", dvnode->netfs.inode.i_ino);
+
+ if (!afs_dir_init_iter(&iter, name))
+ return -ENOENT;
+ do {
+ if (--retry_limit < 0) {
+ pr_warn("afs_read_dir(): Too many retries\n");
+ ret = -ESTALE;
+ break;
+ }
+ ret = afs_read_dir(dvnode, NULL);
+ if (ret < 0) {
+ if (ret != -ESTALE)
+ break;
+ if (test_bit(AFS_VNODE_DELETED, &dvnode->flags)) {
+ ret = -ESTALE;
+ break;
+ }
+ continue;
+ }
+ *_dir_version = inode_peek_iversion_raw(&dvnode->netfs.inode);
+
+ ret = afs_dir_search_bucket(&iter, name, _fid);
+ up_read(&dvnode->validate_lock);
+ if (ret == -ESTALE)
+ afs_dir_reset_iter(&iter);
+ } while (ret == -ESTALE);
+
+ _leave(" = %d", ret);
+ return ret;
+}
*/
struct afs_dir_iter {
struct afs_vnode *dvnode;
+ union afs_xdr_dir_block *block;
struct folio_queue *fq;
unsigned int fpos;
int fq_slot;
+ unsigned int loop_check;
+ u8 nr_slots;
+ u8 bucket;
+ unsigned int prev_entry;
};
#include <trace/events/afs.h>
extern const struct dentry_operations afs_fs_dentry_operations;
ssize_t afs_read_single(struct afs_vnode *dvnode, struct file *file);
+ssize_t afs_read_dir(struct afs_vnode *dvnode, struct file *file)
+ __acquires(&dvnode->validate_lock);
extern void afs_d_release(struct dentry *);
extern void afs_check_for_remote_deletion(struct afs_operation *);
int afs_single_writepages(struct address_space *mapping,
enum afs_edit_dir_reason why);
void afs_mkdir_init_dir(struct afs_vnode *dvnode, struct afs_vnode *parent_vnode);
+/*
+ * dir_search.c
+ */
+unsigned int afs_dir_hash_name(const struct qstr *name);
+bool afs_dir_init_iter(struct afs_dir_iter *iter, const struct qstr *name);
+union afs_xdr_dir_block *afs_dir_find_block(struct afs_dir_iter *iter, size_t block);
+int afs_dir_search_bucket(struct afs_dir_iter *iter, const struct qstr *name,
+ struct afs_fid *_fid);
+int afs_dir_search(struct afs_vnode *dvnode, struct qstr *name,
+ struct afs_fid *_fid, afs_dataversion_t *_dir_version);
+
/*
* dir_silly.c
*/
projects / nvme.git / commitdiff