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afs: Locally edit directory data for mkdir/create/unlink/...
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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 <[email protected]>
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@dhowells
dhowells committed Apr 9, 2018
1 parent 0031763 commit 63a4681
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Showing 8 changed files with 715 additions and 29 deletions.
1 change: 1 addition & 0 deletions fs/afs/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ kafs-objs := \
cell.o \
cmservice.o \
dir.o \
dir_edit.o \
dynroot.o \
file.o \
flock.o \
Expand Down
83 changes: 74 additions & 9 deletions fs/afs/dir.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -1114,6 +1123,7 @@ 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;
Expand All @@ -1131,7 +1141,7 @@ 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);
}

Expand All @@ -1145,6 +1155,11 @@ 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;
Expand All @@ -1168,6 +1183,7 @@ 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);
}
}

Expand All @@ -1179,6 +1195,7 @@ 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}",
Expand All @@ -1194,13 +1211,18 @@ 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);
Expand Down Expand Up @@ -1265,6 +1287,7 @@ 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}",
Expand All @@ -1291,7 +1314,8 @@ 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);
Expand All @@ -1300,6 +1324,10 @@ 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:
Expand All @@ -1321,6 +1349,7 @@ 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;
Expand All @@ -1342,7 +1371,7 @@ 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);
}

Expand All @@ -1356,6 +1385,10 @@ 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;
Expand All @@ -1377,10 +1410,12 @@ 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,
Expand All @@ -1407,7 +1442,7 @@ 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);
Expand All @@ -1423,6 +1458,10 @@ 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;
Expand All @@ -1446,6 +1485,7 @@ 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",
Expand All @@ -1470,7 +1510,8 @@ 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);
}

Expand All @@ -1484,6 +1525,10 @@ 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;
Expand All @@ -1506,6 +1551,8 @@ 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)
Expand All @@ -1514,6 +1561,8 @@ 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,
Expand All @@ -1539,7 +1588,8 @@ 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);
Expand All @@ -1551,6 +1601,21 @@ 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:
Expand Down
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