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Subject[PATCH 17/20] afs: Locally edit directory data for mkdir/create/unlink/...
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Date
Locally edit the contents of an AFS directory upon a successful inode
operation that modifies that directory (such as mkdir, create and unlink)
so that we can avoid the current practice of re-downloading the directory
after each change.

This is viable provided that the directory version number we get back from
the modifying RPC op is exactly incremented by 1 from what we had
previously. The data in the directory contents is in a defined format that
we have to parse locally to perform lookups and readdir, so modifying isn't
a problem.

If the edit fails, we just clear the VALID flag on the directory and it
will be reloaded next time it is needed.

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/afs/Makefile | 1
fs/afs/dir.c | 83 ++++++-
fs/afs/dir_edit.c | 505 ++++++++++++++++++++++++++++++++++++++++++++
fs/afs/fsclient.c | 35 ++-
fs/afs/inode.c | 7 -
fs/afs/internal.h | 19 +-
fs/afs/proc.c | 4
include/trace/events/afs.h | 90 ++++++++
8 files changed, 715 insertions(+), 29 deletions(-)
create mode 100644 fs/afs/dir_edit.c

diff --git a/fs/afs/Makefile b/fs/afs/Makefile
index 6a055423c192..532acae25453 100644
--- a/fs/afs/Makefile
+++ b/fs/afs/Makefile
@@ -12,6 +12,7 @@ kafs-objs := \
cell.o \
cmservice.o \
dir.o \
+ dir_edit.o \
dynroot.o \
file.o \
flock.o \
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 9efaa1f53bd8..7701e382fa94 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -130,17 +130,26 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
qty /= sizeof(union afs_xdr_dir_block);

/* check them */
- dbuf = page_address(page);
+ dbuf = kmap(page);
for (tmp = 0; tmp < qty; tmp++) {
if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
__func__, dvnode->vfs_inode.i_ino, tmp, qty,
ntohs(dbuf->blocks[tmp].hdr.magic));
trace_afs_dir_check_failed(dvnode, off, i_size);
+ kunmap(page);
goto error;
}
+
+ /* Make sure each block is NUL terminated so we can reasonably
+ * use string functions on it. The filenames in the page
+ * *should* be NUL-terminated anyway.
+ */
+ ((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
}

+ kunmap(page);
+
checked:
afs_stat_v(dvnode, n_read_dir);
return true;
@@ -1127,6 +1136,7 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_fid newfid;
struct key *key;
+ u64 data_version = dvnode->status.data_version;
int ret;

mode |= S_IFDIR;
@@ -1144,7 +1154,7 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
- afs_fs_create(&fc, dentry->d_name.name, mode,
+ afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
&newfid, &newstatus, &newcb);
}

@@ -1158,6 +1168,11 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
goto error_key;
}

+ if (ret == 0 &&
+ test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_add(dvnode, &dentry->d_name, &newfid,
+ afs_edit_dir_for_create);
+
key_put(key);
_leave(" = 0");
return 0;
@@ -1181,6 +1196,7 @@ static void afs_dir_remove_subdir(struct dentry *dentry)
clear_nlink(&vnode->vfs_inode);
set_bit(AFS_VNODE_DELETED, &vnode->flags);
clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
}
}

@@ -1192,6 +1208,7 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
struct afs_fs_cursor fc;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct key *key;
+ u64 data_version = dvnode->status.data_version;
int ret;

_enter("{%x:%u},{%pd}",
@@ -1207,13 +1224,18 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
- afs_fs_remove(&fc, dentry->d_name.name, true);
+ afs_fs_remove(&fc, dentry->d_name.name, true,
+ data_version);
}

afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
ret = afs_end_vnode_operation(&fc);
- if (ret == 0)
+ if (ret == 0) {
afs_dir_remove_subdir(dentry);
+ if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_remove(dvnode, &dentry->d_name,
+ afs_edit_dir_for_rmdir);
+ }
}

key_put(key);
@@ -1278,6 +1300,7 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode;
struct key *key;
unsigned long d_version = (unsigned long)dentry->d_fsdata;
+ u64 data_version = dvnode->status.data_version;
int ret;

_enter("{%x:%u},{%pd}",
@@ -1304,7 +1327,8 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
- afs_fs_remove(&fc, dentry->d_name.name, false);
+ afs_fs_remove(&fc, dentry->d_name.name, false,
+ data_version);
}

afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
@@ -1313,6 +1337,10 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
ret = afs_dir_remove_link(
dentry, key, d_version,
(unsigned long)dvnode->status.data_version);
+ if (ret == 0 &&
+ test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_remove(dvnode, &dentry->d_name,
+ afs_edit_dir_for_unlink);
}

error_key:
@@ -1334,6 +1362,7 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_fid newfid;
struct key *key;
+ u64 data_version = dvnode->status.data_version;
int ret;

mode |= S_IFREG;
@@ -1355,7 +1384,7 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
- afs_fs_create(&fc, dentry->d_name.name, mode,
+ afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
&newfid, &newstatus, &newcb);
}

@@ -1369,6 +1398,10 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
goto error_key;
}

+ if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_add(dvnode, &dentry->d_name, &newfid,
+ afs_edit_dir_for_create);
+
key_put(key);
_leave(" = 0");
return 0;
@@ -1390,10 +1423,12 @@ static int afs_link(struct dentry *from, struct inode *dir,
struct afs_fs_cursor fc;
struct afs_vnode *dvnode, *vnode;
struct key *key;
+ u64 data_version;
int ret;

vnode = AFS_FS_I(d_inode(from));
dvnode = AFS_FS_I(dir);
+ data_version = dvnode->status.data_version;

_enter("{%x:%u},{%x:%u},{%pd}",
vnode->fid.vid, vnode->fid.vnode,
@@ -1420,7 +1455,7 @@ static int afs_link(struct dentry *from, struct inode *dir,
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
fc.cb_break_2 = vnode->cb_break + vnode->cb_s_break;
- afs_fs_link(&fc, vnode, dentry->d_name.name);
+ afs_fs_link(&fc, vnode, dentry->d_name.name, data_version);
}

afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
@@ -1436,6 +1471,10 @@ static int afs_link(struct dentry *from, struct inode *dir,
goto error_key;
}

+ if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_add(dvnode, &dentry->d_name, &vnode->fid,
+ afs_edit_dir_for_link);
+
key_put(key);
_leave(" = 0");
return 0;
@@ -1459,6 +1498,7 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry,
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_fid newfid;
struct key *key;
+ u64 data_version = dvnode->status.data_version;
int ret;

_enter("{%x:%u},{%pd},%s",
@@ -1483,7 +1523,8 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry,
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
- afs_fs_symlink(&fc, dentry->d_name.name, content,
+ afs_fs_symlink(&fc, dentry->d_name.name,
+ content, data_version,
&newfid, &newstatus);
}

@@ -1497,6 +1538,10 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry,
goto error_key;
}

+ if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_add(dvnode, &dentry->d_name, &newfid,
+ afs_edit_dir_for_symlink);
+
key_put(key);
_leave(" = 0");
return 0;
@@ -1519,6 +1564,8 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct afs_fs_cursor fc;
struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
struct key *key;
+ u64 orig_data_version, new_data_version;
+ bool new_negative = d_is_negative(new_dentry);
int ret;

if (flags)
@@ -1527,6 +1574,8 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
vnode = AFS_FS_I(d_inode(old_dentry));
orig_dvnode = AFS_FS_I(old_dir);
new_dvnode = AFS_FS_I(new_dir);
+ orig_data_version = orig_dvnode->status.data_version;
+ new_data_version = new_dvnode->status.data_version;

_enter("{%x:%u},{%x:%u},{%x:%u},{%pd}",
orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
@@ -1552,7 +1601,8 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
fc.cb_break = orig_dvnode->cb_break + orig_dvnode->cb_s_break;
fc.cb_break_2 = new_dvnode->cb_break + new_dvnode->cb_s_break;
afs_fs_rename(&fc, old_dentry->d_name.name,
- new_dvnode, new_dentry->d_name.name);
+ new_dvnode, new_dentry->d_name.name,
+ orig_data_version, new_data_version);
}

afs_vnode_commit_status(&fc, orig_dvnode, fc.cb_break);
@@ -1564,6 +1614,21 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
goto error_key;
}

+ if (ret == 0) {
+ if (test_bit(AFS_VNODE_DIR_VALID, &orig_dvnode->flags))
+ afs_edit_dir_remove(orig_dvnode, &old_dentry->d_name,
+ afs_edit_dir_for_rename);
+
+ if (!new_negative &&
+ test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
+ afs_edit_dir_remove(new_dvnode, &new_dentry->d_name,
+ afs_edit_dir_for_rename);
+
+ if (test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
+ afs_edit_dir_add(new_dvnode, &new_dentry->d_name,
+ &vnode->fid, afs_edit_dir_for_rename);
+ }
+
error_key:
key_put(key);
error:
diff --git a/fs/afs/dir_edit.c b/fs/afs/dir_edit.c
new file mode 100644
index 000000000000..8b400f5aead5
--- /dev/null
+++ b/fs/afs/dir_edit.c
@@ -0,0 +1,505 @@
+/* AFS filesystem directory editing
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/pagemap.h>
+#include <linux/iversion.h>
+#include "internal.h"
+#include "xdr_fs.h"
+
+/*
+ * Find a number of contiguous clear bits in a directory block bitmask.
+ *
+ * There are 64 slots, which means we can load the entire bitmap into a
+ * variable. The first bit doesn't count as it corresponds to the block header
+ * slot. nr_slots is between 1 and 9.
+ */
+static int afs_find_contig_bits(union afs_xdr_dir_block *block, unsigned int nr_slots)
+{
+ u64 bitmap;
+ u32 mask;
+ int bit, n;
+
+ bitmap = (u64)block->hdr.bitmap[0] << 0 * 8;
+ bitmap |= (u64)block->hdr.bitmap[1] << 1 * 8;
+ bitmap |= (u64)block->hdr.bitmap[2] << 2 * 8;
+ bitmap |= (u64)block->hdr.bitmap[3] << 3 * 8;
+ bitmap |= (u64)block->hdr.bitmap[4] << 4 * 8;
+ bitmap |= (u64)block->hdr.bitmap[5] << 5 * 8;
+ bitmap |= (u64)block->hdr.bitmap[6] << 6 * 8;
+ bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
+ bitmap >>= 1; /* The first entry is metadata */
+ bit = 1;
+ mask = (1 << nr_slots) - 1;
+
+ do {
+ if (sizeof(unsigned long) == 8)
+ n = ffz(bitmap);
+ else
+ n = ((u32)bitmap) != 0 ?
+ ffz((u32)bitmap) :
+ ffz((u32)(bitmap >> 32)) + 32;
+ bitmap >>= n;
+ bit += n;
+
+ if ((bitmap & mask) == 0) {
+ if (bit > 64 - nr_slots)
+ return -1;
+ return bit;
+ }
+
+ n = __ffs(bitmap);
+ bitmap >>= n;
+ bit += n;
+ } while (bitmap);
+
+ return -1;
+}
+
+/*
+ * Set a number of contiguous bits in the directory block bitmap.
+ */
+static void afs_set_contig_bits(union afs_xdr_dir_block *block,
+ int bit, unsigned int nr_slots)
+{
+ u64 mask, before, after;
+
+ mask = (1 << nr_slots) - 1;
+ mask <<= bit;
+
+ before = *(u64 *)block->hdr.bitmap;
+
+ block->hdr.bitmap[0] |= (u8)(mask >> 0 * 8);
+ block->hdr.bitmap[1] |= (u8)(mask >> 1 * 8);
+ block->hdr.bitmap[2] |= (u8)(mask >> 2 * 8);
+ block->hdr.bitmap[3] |= (u8)(mask >> 3 * 8);
+ block->hdr.bitmap[4] |= (u8)(mask >> 4 * 8);
+ block->hdr.bitmap[5] |= (u8)(mask >> 5 * 8);
+ block->hdr.bitmap[6] |= (u8)(mask >> 6 * 8);
+ block->hdr.bitmap[7] |= (u8)(mask >> 7 * 8);
+
+ after = *(u64 *)block->hdr.bitmap;
+}
+
+/*
+ * Clear a number of contiguous bits in the directory block bitmap.
+ */
+static void afs_clear_contig_bits(union afs_xdr_dir_block *block,
+ int bit, unsigned int nr_slots)
+{
+ u64 mask, before, after;
+
+ mask = (1 << nr_slots) - 1;
+ mask <<= bit;
+
+ before = *(u64 *)block->hdr.bitmap;
+
+ block->hdr.bitmap[0] &= ~(u8)(mask >> 0 * 8);
+ block->hdr.bitmap[1] &= ~(u8)(mask >> 1 * 8);
+ block->hdr.bitmap[2] &= ~(u8)(mask >> 2 * 8);
+ block->hdr.bitmap[3] &= ~(u8)(mask >> 3 * 8);
+ block->hdr.bitmap[4] &= ~(u8)(mask >> 4 * 8);
+ block->hdr.bitmap[5] &= ~(u8)(mask >> 5 * 8);
+ block->hdr.bitmap[6] &= ~(u8)(mask >> 6 * 8);
+ block->hdr.bitmap[7] &= ~(u8)(mask >> 7 * 8);
+
+ after = *(u64 *)block->hdr.bitmap;
+}
+
+/*
+ * Scan a directory block looking for a dirent of the right name.
+ */
+static int afs_dir_scan_block(union afs_xdr_dir_block *block, struct qstr *name,
+ unsigned int blocknum)
+{
+ union afs_xdr_dirent *de;
+ u64 bitmap;
+ int d, len, n;
+
+ _enter("");
+
+ bitmap = (u64)block->hdr.bitmap[0] << 0 * 8;
+ bitmap |= (u64)block->hdr.bitmap[1] << 1 * 8;
+ bitmap |= (u64)block->hdr.bitmap[2] << 2 * 8;
+ bitmap |= (u64)block->hdr.bitmap[3] << 3 * 8;
+ bitmap |= (u64)block->hdr.bitmap[4] << 4 * 8;
+ bitmap |= (u64)block->hdr.bitmap[5] << 5 * 8;
+ bitmap |= (u64)block->hdr.bitmap[6] << 6 * 8;
+ bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
+
+ for (d = (blocknum == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
+ d < AFS_DIR_SLOTS_PER_BLOCK;
+ d++) {
+ if (!((bitmap >> d) & 1))
+ continue;
+ de = &block->dirents[d];
+ if (de->u.valid != 1)
+ continue;
+
+ /* The block was NUL-terminated by afs_dir_check_page(). */
+ len = strlen(de->u.name);
+ if (len == name->len &&
+ memcmp(de->u.name, name->name, name->len) == 0)
+ return d;
+
+ n = round_up(12 + len + 1 + 4, AFS_DIR_DIRENT_SIZE);
+ n /= AFS_DIR_DIRENT_SIZE;
+ d += n - 1;
+ }
+
+ return -1;
+}
+
+/*
+ * Initialise a new directory block. Note that block 0 is special and contains
+ * some extra metadata.
+ */
+static void afs_edit_init_block(union afs_xdr_dir_block *meta,
+ union afs_xdr_dir_block *block, int block_num)
+{
+ memset(block, 0, sizeof(*block));
+ block->hdr.npages = htons(1);
+ block->hdr.magic = AFS_DIR_MAGIC;
+ block->hdr.bitmap[0] = 1;
+
+ if (block_num == 0) {
+ block->hdr.bitmap[0] = 0xff;
+ block->hdr.bitmap[1] = 0x1f;
+ memset(block->meta.alloc_ctrs,
+ AFS_DIR_SLOTS_PER_BLOCK,
+ sizeof(block->meta.alloc_ctrs));
+ meta->meta.alloc_ctrs[0] =
+ AFS_DIR_SLOTS_PER_BLOCK - AFS_DIR_RESV_BLOCKS0;
+ }
+
+ if (block_num < AFS_DIR_BLOCKS_WITH_CTR)
+ meta->meta.alloc_ctrs[block_num] =
+ AFS_DIR_SLOTS_PER_BLOCK - AFS_DIR_RESV_BLOCKS;
+}
+
+/*
+ * Edit a directory's file data to add a new directory entry. Doing this after
+ * create, mkdir, symlink, link or rename if the data version number is
+ * incremented by exactly one avoids the need to re-download the entire
+ * directory contents.
+ *
+ * The caller must hold the inode locked.
+ */
+void afs_edit_dir_add(struct afs_vnode *vnode,
+ struct qstr *name, struct afs_fid *new_fid,
+ enum afs_edit_dir_reason why)
+{
+ union afs_xdr_dir_block *meta, *block;
+ struct afs_xdr_dir_page *meta_page, *dir_page;
+ union afs_xdr_dirent *de;
+ struct page *page0, *page;
+ unsigned int need_slots, nr_blocks, b;
+ pgoff_t index;
+ loff_t i_size;
+ gfp_t gfp;
+ int slot;
+
+ _enter(",,{%d,%s},", name->len, name->name);
+
+ i_size = i_size_read(&vnode->vfs_inode);
+ if (i_size > AFS_DIR_BLOCK_SIZE * AFS_DIR_MAX_BLOCKS ||
+ (i_size & (AFS_DIR_BLOCK_SIZE - 1))) {
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ return;
+ }
+
+ gfp = vnode->vfs_inode.i_mapping->gfp_mask;
+ page0 = find_or_create_page(vnode->vfs_inode.i_mapping, 0, gfp);
+ if (!page0) {
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ _leave(" [fgp]");
+ return;
+ }
+
+ /* Work out how many slots we're going to need. */
+ need_slots = round_up(12 + name->len + 1 + 4, AFS_DIR_DIRENT_SIZE);
+ need_slots /= AFS_DIR_DIRENT_SIZE;
+
+ meta_page = kmap(page0);
+ meta = &meta_page->blocks[0];
+ if (i_size == 0)
+ goto new_directory;
+ nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
+
+ /* Find a block that has sufficient slots available. Each VM page
+ * contains two or more directory blocks.
+ */
+ for (b = 0; b < nr_blocks + 1; b++) {
+ /* If the directory extended into a new page, then we need to
+ * tack a new page on the end.
+ */
+ index = b / AFS_DIR_BLOCKS_PER_PAGE;
+ if (index == 0) {
+ page = page0;
+ dir_page = meta_page;
+ } else {
+ if (nr_blocks >= AFS_DIR_MAX_BLOCKS)
+ goto error;
+ gfp = vnode->vfs_inode.i_mapping->gfp_mask;
+ page = find_or_create_page(vnode->vfs_inode.i_mapping,
+ index, gfp);
+ if (!page)
+ goto error;
+ if (!PagePrivate(page)) {
+ set_page_private(page, 1);
+ SetPagePrivate(page);
+ }
+ dir_page = kmap(page);
+ }
+
+ /* Abandon the edit if we got a callback break. */
+ if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+ goto invalidated;
+
+ block = &dir_page->blocks[b % AFS_DIR_BLOCKS_PER_PAGE];
+
+ _debug("block %u: %2u %3u %u",
+ b,
+ (b < AFS_DIR_BLOCKS_WITH_CTR) ? meta->meta.alloc_ctrs[b] : 99,
+ ntohs(block->hdr.npages),
+ ntohs(block->hdr.magic));
+
+ /* Initialise the block if necessary. */
+ if (b == nr_blocks) {
+ _debug("init %u", b);
+ afs_edit_init_block(meta, block, b);
+ i_size_write(&vnode->vfs_inode, (b + 1) * AFS_DIR_BLOCK_SIZE);
+ }
+
+ /* Only lower dir pages have a counter in the header. */
+ if (b >= AFS_DIR_BLOCKS_WITH_CTR ||
+ meta->meta.alloc_ctrs[b] >= need_slots) {
+ /* We need to try and find one or more consecutive
+ * slots to hold the entry.
+ */
+ slot = afs_find_contig_bits(block, need_slots);
+ if (slot >= 0) {
+ _debug("slot %u", slot);
+ goto found_space;
+ }
+ }
+
+ if (page != page0) {
+ unlock_page(page);
+ kunmap(page);
+ put_page(page);
+ }
+ }
+
+ /* There are no spare slots of sufficient size, yet the operation
+ * succeeded. Download the directory again.
+ */
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_create_nospc, 0, 0, 0, 0, name->name);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ goto out_unmap;
+
+new_directory:
+ afs_edit_init_block(meta, meta, 0);
+ i_size = AFS_DIR_BLOCK_SIZE;
+ i_size_write(&vnode->vfs_inode, i_size);
+ slot = AFS_DIR_RESV_BLOCKS0;
+ page = page0;
+ block = meta;
+ nr_blocks = 1;
+ b = 0;
+
+found_space:
+ /* Set the dirent slot. */
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_create, b, slot,
+ new_fid->vnode, new_fid->unique, name->name);
+ de = &block->dirents[slot];
+ de->u.valid = 1;
+ de->u.unused[0] = 0;
+ de->u.hash_next = 0; // TODO: Really need to maintain this
+ de->u.vnode = htonl(new_fid->vnode);
+ de->u.unique = htonl(new_fid->unique);
+ memcpy(de->u.name, name->name, name->len + 1);
+ de->u.name[name->len] = 0;
+
+ /* Adjust the bitmap. */
+ afs_set_contig_bits(block, slot, need_slots);
+ if (page != page0) {
+ unlock_page(page);
+ kunmap(page);
+ put_page(page);
+ }
+
+ /* Adjust the allocation counter. */
+ if (b < AFS_DIR_BLOCKS_WITH_CTR)
+ meta->meta.alloc_ctrs[b] -= need_slots;
+
+ inode_inc_iversion_raw(&vnode->vfs_inode);
+ afs_stat_v(vnode, n_dir_cr);
+ _debug("Insert %s in %u[%u]", name->name, b, slot);
+
+out_unmap:
+ unlock_page(page0);
+ kunmap(page0);
+ put_page(page0);
+ _leave("");
+ return;
+
+invalidated:
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_create_inval, 0, 0, 0, 0, name->name);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ if (page != page0) {
+ kunmap(page);
+ put_page(page);
+ }
+ goto out_unmap;
+
+error:
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_create_error, 0, 0, 0, 0, name->name);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ goto out_unmap;
+}
+
+/*
+ * Edit a directory's file data to remove a new directory entry. Doing this
+ * after unlink, rmdir or rename if the data version number is incremented by
+ * exactly one avoids the need to re-download the entire directory contents.
+ *
+ * The caller must hold the inode locked.
+ */
+void afs_edit_dir_remove(struct afs_vnode *vnode,
+ struct qstr *name, enum afs_edit_dir_reason why)
+{
+ struct afs_xdr_dir_page *meta_page, *dir_page;
+ union afs_xdr_dir_block *meta, *block;
+ union afs_xdr_dirent *de;
+ struct page *page0, *page;
+ unsigned int need_slots, nr_blocks, b;
+ pgoff_t index;
+ loff_t i_size;
+ int slot;
+
+ _enter(",,{%d,%s},", name->len, name->name);
+
+ i_size = i_size_read(&vnode->vfs_inode);
+ if (i_size < AFS_DIR_BLOCK_SIZE ||
+ i_size > AFS_DIR_BLOCK_SIZE * AFS_DIR_MAX_BLOCKS ||
+ (i_size & (AFS_DIR_BLOCK_SIZE - 1))) {
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ return;
+ }
+ nr_blocks = i_size / AFS_DIR_BLOCK_SIZE;
+
+ page0 = find_lock_page(vnode->vfs_inode.i_mapping, 0);
+ if (!page0) {
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ _leave(" [fgp]");
+ return;
+ }
+
+ /* Work out how many slots we're going to discard. */
+ need_slots = round_up(12 + name->len + 1 + 4, AFS_DIR_DIRENT_SIZE);
+ need_slots /= AFS_DIR_DIRENT_SIZE;
+
+ meta_page = kmap(page0);
+ meta = &meta_page->blocks[0];
+
+ /* Find a page that has sufficient slots available. Each VM page
+ * contains two or more directory blocks.
+ */
+ for (b = 0; b < nr_blocks; b++) {
+ index = b / AFS_DIR_BLOCKS_PER_PAGE;
+ if (index != 0) {
+ page = find_lock_page(vnode->vfs_inode.i_mapping, index);
+ if (!page)
+ goto error;
+ dir_page = kmap(page);
+ } else {
+ page = page0;
+ dir_page = meta_page;
+ }
+
+ /* Abandon the edit if we got a callback break. */
+ if (!test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+ goto invalidated;
+
+ block = &dir_page->blocks[b % AFS_DIR_BLOCKS_PER_PAGE];
+
+ 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;
+ }
+
+ if (page != page0) {
+ unlock_page(page);
+ kunmap(page);
+ put_page(page);
+ }
+ }
+
+ /* 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);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ goto out_unmap;
+
+found_dirent:
+ de = &block->dirents[slot];
+
+ 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);
+ if (page != page0) {
+ unlock_page(page);
+ kunmap(page);
+ put_page(page);
+ }
+
+ /* Adjust the allocation counter. */
+ if (b < AFS_DIR_BLOCKS_WITH_CTR)
+ meta->meta.alloc_ctrs[b] += need_slots;
+
+ inode_set_iversion_raw(&vnode->vfs_inode, vnode->status.data_version);
+ afs_stat_v(vnode, n_dir_rm);
+ _debug("Remove %s from %u[%u]", name->name, b, slot);
+
+out_unmap:
+ unlock_page(page0);
+ kunmap(page0);
+ put_page(page0);
+ _leave("");
+ return;
+
+invalidated:
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_inval,
+ 0, 0, 0, 0, name->name);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ if (page != page0) {
+ unlock_page(page);
+ kunmap(page);
+ put_page(page);
+ }
+ goto out_unmap;
+
+error:
+ trace_afs_edit_dir(vnode, why, afs_edit_dir_delete_error,
+ 0, 0, 0, 0, name->name);
+ clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
+ goto out_unmap;
+}
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index b66ff0dc8a5a..20d6304a0d3e 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -107,6 +107,13 @@ void afs_update_inode_from_status(struct afs_vnode *vnode,
} else {
set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
}
+ } else if (vnode->status.type == AFS_FTYPE_DIR) {
+ /* Expected directory change is handled elsewhere so
+ * that we can locally edit the directory and save on a
+ * download.
+ */
+ if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
+ flags &= ~AFS_VNODE_DATA_CHANGED;
}
}

@@ -190,10 +197,7 @@ static int xdr_decode_AFSFetchStatus(const __be32 **_bp,

size = (u64)ntohl(xdr->size_lo);
size |= (u64)ntohl(xdr->size_hi) << 32;
- if (size != status->size) {
- status->size = size;
- flags |= AFS_VNODE_DATA_CHANGED;
- }
+ status->size = size;

data_version = (u64)ntohl(xdr->data_version_lo);
data_version |= (u64)ntohl(xdr->data_version_hi) << 32;
@@ -736,6 +740,7 @@ static const struct afs_call_type afs_RXFSMakeDir = {
int afs_fs_create(struct afs_fs_cursor *fc,
const char *name,
umode_t mode,
+ u64 current_data_version,
struct afs_fid *newfid,
struct afs_file_status *newstatus,
struct afs_callback *newcb)
@@ -763,7 +768,7 @@ int afs_fs_create(struct afs_fs_cursor *fc,
call->reply[1] = newfid;
call->reply[2] = newstatus;
call->reply[3] = newcb;
- call->expected_version = vnode->status.data_version;
+ call->expected_version = current_data_version + 1;

/* marshall the parameters */
bp = call->request;
@@ -836,7 +841,8 @@ static const struct afs_call_type afs_RXFSRemoveDir = {
/*
* remove a file or directory
*/
-int afs_fs_remove(struct afs_fs_cursor *fc, const char *name, bool isdir)
+int afs_fs_remove(struct afs_fs_cursor *fc, const char *name, bool isdir,
+ u64 current_data_version)
{
struct afs_vnode *vnode = fc->vnode;
struct afs_call *call;
@@ -858,7 +864,7 @@ int afs_fs_remove(struct afs_fs_cursor *fc, const char *name, bool isdir)

call->key = fc->key;
call->reply[0] = vnode;
- call->expected_version = vnode->status.data_version;
+ call->expected_version = current_data_version + 1;

/* marshall the parameters */
bp = call->request;
@@ -920,7 +926,7 @@ static const struct afs_call_type afs_RXFSLink = {
* make a hard link
*/
int afs_fs_link(struct afs_fs_cursor *fc, struct afs_vnode *vnode,
- const char *name)
+ const char *name, u64 current_data_version)
{
struct afs_vnode *dvnode = fc->vnode;
struct afs_call *call;
@@ -941,7 +947,7 @@ int afs_fs_link(struct afs_fs_cursor *fc, struct afs_vnode *vnode,
call->key = fc->key;
call->reply[0] = dvnode;
call->reply[1] = vnode;
- call->expected_version = vnode->status.data_version;
+ call->expected_version = current_data_version + 1;

/* marshall the parameters */
bp = call->request;
@@ -1009,6 +1015,7 @@ static const struct afs_call_type afs_RXFSSymlink = {
int afs_fs_symlink(struct afs_fs_cursor *fc,
const char *name,
const char *contents,
+ u64 current_data_version,
struct afs_fid *newfid,
struct afs_file_status *newstatus)
{
@@ -1037,7 +1044,7 @@ int afs_fs_symlink(struct afs_fs_cursor *fc,
call->reply[0] = vnode;
call->reply[1] = newfid;
call->reply[2] = newstatus;
- call->expected_version = vnode->status.data_version;
+ call->expected_version = current_data_version + 1;

/* marshall the parameters */
bp = call->request;
@@ -1117,7 +1124,9 @@ static const struct afs_call_type afs_RXFSRename = {
int afs_fs_rename(struct afs_fs_cursor *fc,
const char *orig_name,
struct afs_vnode *new_dvnode,
- const char *new_name)
+ const char *new_name,
+ u64 current_orig_data_version,
+ u64 current_new_data_version)
{
struct afs_vnode *orig_dvnode = fc->vnode;
struct afs_call *call;
@@ -1145,8 +1154,8 @@ int afs_fs_rename(struct afs_fs_cursor *fc,
call->key = fc->key;
call->reply[0] = orig_dvnode;
call->reply[1] = new_dvnode;
- call->expected_version = orig_dvnode->status.data_version;
- call->expected_version_2 = new_dvnode->status.data_version;
+ call->expected_version = current_orig_data_version + 1;
+ call->expected_version_2 = current_new_data_version + 1;

/* marshall the parameters */
bp = call->request;
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 69bcfb82dd69..3808dcbbac6d 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -395,8 +395,11 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) {
vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
- } else if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags) &&
- !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
+ } else if (vnode->status.type == AFS_FTYPE_DIR &&
+ test_bit(AFS_VNODE_DIR_VALID, &vnode->flags) &&
+ vnode->cb_expires_at - 10 > now) {
+ valid = true;
+ } else if (!test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
vnode->cb_expires_at - 10 > now) {
valid = true;
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 3a73c87e7ca8..b4d2fac46fe8 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -269,6 +269,8 @@ struct afs_net {
atomic_t n_inval; /* Number of invalidations by the server */
atomic_t n_relpg; /* Number of invalidations by releasepage */
atomic_t n_read_dir; /* Number of directory pages read */
+ atomic_t n_dir_cr; /* Number of directory entry creation edits */
+ atomic_t n_dir_rm; /* Number of directory entry removal edits */
};

extern const char afs_init_sysname[];
@@ -677,6 +679,13 @@ extern const struct dentry_operations afs_fs_dentry_operations;

extern void afs_d_release(struct dentry *);

+/*
+ * dir_edit.c
+ */
+extern void afs_edit_dir_add(struct afs_vnode *, struct qstr *, struct afs_fid *,
+ enum afs_edit_dir_reason);
+extern void afs_edit_dir_remove(struct afs_vnode *, struct qstr *, enum afs_edit_dir_reason);
+
/*
* dynroot.c
*/
@@ -723,14 +732,14 @@ extern void afs_update_inode_from_status(struct afs_vnode *, struct afs_file_sta
extern int afs_fs_fetch_file_status(struct afs_fs_cursor *, struct afs_volsync *, bool);
extern int afs_fs_give_up_callbacks(struct afs_net *, struct afs_server *);
extern int afs_fs_fetch_data(struct afs_fs_cursor *, struct afs_read *);
-extern int afs_fs_create(struct afs_fs_cursor *, const char *, umode_t,
+extern int afs_fs_create(struct afs_fs_cursor *, const char *, umode_t, u64,
struct afs_fid *, struct afs_file_status *, struct afs_callback *);
-extern int afs_fs_remove(struct afs_fs_cursor *, const char *, bool);
-extern int afs_fs_link(struct afs_fs_cursor *, struct afs_vnode *, const char *);
-extern int afs_fs_symlink(struct afs_fs_cursor *, const char *, const char *,
+extern int afs_fs_remove(struct afs_fs_cursor *, const char *, bool, u64);
+extern int afs_fs_link(struct afs_fs_cursor *, struct afs_vnode *, const char *, u64);
+extern int afs_fs_symlink(struct afs_fs_cursor *, const char *, const char *, u64,
struct afs_fid *, struct afs_file_status *);
extern int afs_fs_rename(struct afs_fs_cursor *, const char *,
- struct afs_vnode *, const char *);
+ struct afs_vnode *, const char *, u64, u64);
extern int afs_fs_store_data(struct afs_fs_cursor *, struct address_space *,
pgoff_t, pgoff_t, unsigned, unsigned);
extern int afs_fs_setattr(struct afs_fs_cursor *, struct iattr *);
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 090fa8c30ea8..5ced655d08b3 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -898,6 +898,10 @@ static int afs_proc_stats_show(struct seq_file *m, void *v)

seq_printf(m, "dir-data: rdpg=%u\n",
atomic_read(&net->n_read_dir));
+
+ seq_printf(m, "dir-edit: cr=%u rm=%u\n",
+ atomic_read(&net->n_dir_cr),
+ atomic_read(&net->n_dir_rm));
return 0;
}

diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 0419b7e1e968..f46dee0f5ced 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -63,6 +63,27 @@ enum afs_vl_operation {
afs_VL_GetCapabilities = 65537, /* AFS Get VL server capabilities */
};

+enum afs_edit_dir_op {
+ afs_edit_dir_create,
+ afs_edit_dir_create_error,
+ afs_edit_dir_create_inval,
+ afs_edit_dir_create_nospc,
+ afs_edit_dir_delete,
+ afs_edit_dir_delete_error,
+ afs_edit_dir_delete_inval,
+ afs_edit_dir_delete_noent,
+};
+
+enum afs_edit_dir_reason {
+ afs_edit_dir_for_create,
+ afs_edit_dir_for_link,
+ afs_edit_dir_for_mkdir,
+ afs_edit_dir_for_rename,
+ afs_edit_dir_for_rmdir,
+ afs_edit_dir_for_symlink,
+ afs_edit_dir_for_unlink,
+};
+
#endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */

/*
@@ -106,6 +127,25 @@ enum afs_vl_operation {
EM(afs_YFSVL_GetEndpoints, "YFSVL.GetEndpoints") \
E_(afs_VL_GetCapabilities, "VL.GetCapabilities")

+#define afs_edit_dir_ops \
+ EM(afs_edit_dir_create, "create") \
+ EM(afs_edit_dir_create_error, "c_fail") \
+ EM(afs_edit_dir_create_inval, "c_invl") \
+ EM(afs_edit_dir_create_nospc, "c_nspc") \
+ EM(afs_edit_dir_delete, "delete") \
+ EM(afs_edit_dir_delete_error, "d_err ") \
+ EM(afs_edit_dir_delete_inval, "d_invl") \
+ E_(afs_edit_dir_delete_noent, "d_nent")
+
+#define afs_edit_dir_reasons \
+ EM(afs_edit_dir_for_create, "Create") \
+ EM(afs_edit_dir_for_link, "Link ") \
+ EM(afs_edit_dir_for_mkdir, "MkDir ") \
+ EM(afs_edit_dir_for_rename, "Rename") \
+ EM(afs_edit_dir_for_rmdir, "RmDir ") \
+ EM(afs_edit_dir_for_symlink, "Symlnk") \
+ E_(afs_edit_dir_for_unlink, "Unlink")
+

/*
* Export enum symbols via userspace.
@@ -118,6 +158,8 @@ enum afs_vl_operation {
afs_call_traces;
afs_fs_operations;
afs_vl_operations;
+afs_edit_dir_ops;
+afs_edit_dir_reasons;

/*
* Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -464,6 +506,54 @@ TRACE_EVENT(afs_call_state,
__entry->ret, __entry->abort)
);

+TRACE_EVENT(afs_edit_dir,
+ TP_PROTO(struct afs_vnode *dvnode,
+ enum afs_edit_dir_reason why,
+ enum afs_edit_dir_op op,
+ unsigned int block,
+ unsigned int slot,
+ unsigned int f_vnode,
+ unsigned int f_unique,
+ const char *name),
+
+ TP_ARGS(dvnode, why, op, block, slot, f_vnode, f_unique, name),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, vnode )
+ __field(unsigned int, unique )
+ __field(enum afs_edit_dir_reason, why )
+ __field(enum afs_edit_dir_op, op )
+ __field(unsigned int, block )
+ __field(unsigned short, slot )
+ __field(unsigned int, f_vnode )
+ __field(unsigned int, f_unique )
+ __array(char, name, 18 )
+ ),
+
+ TP_fast_assign(
+ int __len = strlen(name);
+ __len = min(__len, 17);
+ __entry->vnode = dvnode->fid.vnode;
+ __entry->unique = dvnode->fid.unique;
+ __entry->why = why;
+ __entry->op = op;
+ __entry->block = block;
+ __entry->slot = slot;
+ __entry->f_vnode = f_vnode;
+ __entry->f_unique = f_unique;
+ memcpy(__entry->name, name, __len);
+ __entry->name[__len] = 0;
+ ),
+
+ TP_printk("d=%x:%x %s %s %u[%u] f=%x:%x %s",
+ __entry->vnode, __entry->unique,
+ __print_symbolic(__entry->why, afs_edit_dir_reasons),
+ __print_symbolic(__entry->op, afs_edit_dir_ops),
+ __entry->block, __entry->slot,
+ __entry->f_vnode, __entry->f_unique,
+ __entry->name)
+ );
+
#endif /* _TRACE_AFS_H */

/* This part must be outside protection */
\
 
 \ /
  Last update: 2018-04-05 22:34    [W:0.271 / U:10.760 seconds]
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