Skip to content

Commit

Permalink
cifs: Support fscache indexing rewrite
Browse files Browse the repository at this point in the history
Change the cifs filesystem to take account of the changes to fscache's
indexing rewrite and reenable caching in cifs.

The following changes have been made:

 (1) The fscache_netfs struct is no more, and there's no need to register
     the filesystem as a whole.

 (2) The session cookie is now an fscache_volume cookie, allocated with
     fscache_acquire_volume().  That takes three parameters: a string
     representing the "volume" in the index, a string naming the cache to
     use (or NULL) and a u64 that conveys coherency metadata for the
     volume.

     For cifs, I've made it render the volume name string as:

	"cifs,<ipaddress>,<sharename>"

     where the sharename has '/' characters replaced with ';'.

     This probably needs rethinking a bit as the total name could exceed
     the maximum filename component length.

     Further, the coherency data is currently just set to 0.  It needs
     something else doing with it - I wonder if it would suffice simply to
     sum the resource_id, vol_create_time and vol_serial_number or maybe
     hash them.

 (3) The fscache_cookie_def is no more and needed information is passed
     directly to fscache_acquire_cookie().  The cache no longer calls back
     into the filesystem, but rather metadata changes are indicated at
     other times.

     fscache_acquire_cookie() is passed the same keying and coherency
     information as before.

 (4) The functions to set/reset cookies are removed and
     fscache_use_cookie() and fscache_unuse_cookie() are used instead.

     fscache_use_cookie() is passed a flag to indicate if the cookie is
     opened for writing.  fscache_unuse_cookie() is passed updates for the
     metadata if we changed it (ie. if the file was opened for writing).

     These are called when the file is opened or closed.

 (5) cifs_setattr_*() are made to call fscache_resize() to change the size
     of the cache object.

 (6) The functions to read and write data are stubbed out pending a
     conversion to use netfslib.

Changes
=======
ver #8:
 - Abstract cache invalidation into a helper function.
 - Fix some checkpatch warnings[3].

ver #7:
 - Removed the accidentally added-back call to get the super cookie in
   cifs_root_iget().
 - Fixed the right call to cifs_fscache_get_super_cookie() to take account
   of the "-o fsc" mount flag.

ver #6:
 - Moved the change of gfpflags_allow_blocking() to current_is_kswapd() for
   cifs here.
 - Fixed one of the error paths in cifs_atomic_open() to jump around the
   call to use the cookie.
 - Fixed an additional successful return in the middle of cifs_open() to
   use the cookie on the way out.
 - Only get a volume cookie (and thus inode cookies) when "-o fsc" is
   supplied to mount.

ver #5:
 - Fixed a couple of bits of cookie handling[2]:
   - The cookie should be released in cifs_evict_inode(), not
     cifsFileInfo_put_final().  The cookie needs to persist beyond file
     closure so that writepages will be able to write to it.
   - fscache_use_cookie() needs to be called in cifs_atomic_open() as it is
     for cifs_open().

ver #4:
 - Fixed the use of sizeof with memset.
 - tcon->vol_create_time is __le64 so doesn't need cpu_to_le64().

ver #3:
 - Canonicalise the cifs coherency data to make the cache portable.
 - Set volume coherency data.

ver #2:
 - Use gfpflags_allow_blocking() rather than using flag directly.
 - Upgraded to -rc4 to allow for upstream changes[1].
 - fscache_acquire_volume() now returns errors.

Signed-off-by: David Howells <[email protected]>
Acked-by: Jeff Layton <[email protected]>
cc: Steve French <[email protected]>
cc: Shyam Prasad N <[email protected]>
cc: [email protected]
cc: [email protected]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23b55d673d7527b093cd97b7c217c82e70cd1af0 [1]
Link: https://lore.kernel.org/r/[email protected]/ [2]
Link: https://lore.kernel.org/r/CAH2r5muTanw9pJqzAHd01d9A8keeChkzGsCEH6=0rHutVLAF-A@mail.gmail.com/ [3]
Link: https://lore.kernel.org/r/163819671009.215744.11230627184193298714.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906982979.143852.10672081929614953210.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967187187.1823006.247415138444991444.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021579335.640689.2681324337038770579.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/[email protected]/ # v5
Link: https://lore.kernel.org/r/[email protected]/ # v6
Signed-off-by: Steve French <[email protected]>
  • Loading branch information
dhowells authored and Steve French committed Jan 19, 2022
1 parent ba978e8 commit 70431bf
Show file tree
Hide file tree
Showing 11 changed files with 199 additions and 500 deletions.
2 changes: 1 addition & 1 deletion fs/cifs/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -188,7 +188,7 @@ config CIFS_SMB_DIRECT

config CIFS_FSCACHE
bool "Provide CIFS client caching support"
depends on CIFS=m && FSCACHE_OLD_API || CIFS=y && FSCACHE_OLD_API=y
depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
help
Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
to be cached locally on disk through the general filesystem cache
Expand Down
2 changes: 1 addition & 1 deletion fs/cifs/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ cifs-$(CONFIG_CIFS_DFS_UPCALL) += cifs_dfs_ref.o dfs_cache.o

cifs-$(CONFIG_CIFS_SWN_UPCALL) += netlink.o cifs_swn.o

cifs-$(CONFIG_CIFS_FSCACHE) += fscache.o cache.o
cifs-$(CONFIG_CIFS_FSCACHE) += fscache.o

cifs-$(CONFIG_CIFS_SMB_DIRECT) += smbdirect.o

Expand Down
105 changes: 0 additions & 105 deletions fs/cifs/cache.c

This file was deleted.

19 changes: 11 additions & 8 deletions fs/cifs/cifsfs.c
Original file line number Diff line number Diff line change
Expand Up @@ -397,6 +397,9 @@ static void
cifs_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
if (inode->i_state & I_PINNING_FSCACHE_WB)
cifs_fscache_unuse_inode_cookie(inode, true);
cifs_fscache_release_inode_cookie(inode);
clear_inode(inode);
}

Expand Down Expand Up @@ -721,6 +724,12 @@ static int cifs_show_stats(struct seq_file *s, struct dentry *root)
}
#endif

static int cifs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
fscache_unpin_writeback(wbc, cifs_inode_cookie(inode));
return 0;
}

static int cifs_drop_inode(struct inode *inode)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
Expand All @@ -733,6 +742,7 @@ static int cifs_drop_inode(struct inode *inode)
static const struct super_operations cifs_super_ops = {
.statfs = cifs_statfs,
.alloc_inode = cifs_alloc_inode,
.write_inode = cifs_write_inode,
.free_inode = cifs_free_inode,
.drop_inode = cifs_drop_inode,
.evict_inode = cifs_evict_inode,
Expand Down Expand Up @@ -1625,13 +1635,9 @@ init_cifs(void)
goto out_destroy_cifsoplockd_wq;
}

rc = cifs_fscache_register();
if (rc)
goto out_destroy_deferredclose_wq;

rc = cifs_init_inodecache();
if (rc)
goto out_unreg_fscache;
goto out_destroy_deferredclose_wq;

rc = cifs_init_mids();
if (rc)
Expand Down Expand Up @@ -1693,8 +1699,6 @@ init_cifs(void)
cifs_destroy_mids();
out_destroy_inodecache:
cifs_destroy_inodecache();
out_unreg_fscache:
cifs_fscache_unregister();
out_destroy_deferredclose_wq:
destroy_workqueue(deferredclose_wq);
out_destroy_cifsoplockd_wq:
Expand Down Expand Up @@ -1730,7 +1734,6 @@ exit_cifs(void)
cifs_destroy_request_bufs();
cifs_destroy_mids();
cifs_destroy_inodecache();
cifs_fscache_unregister();
destroy_workqueue(deferredclose_wq);
destroy_workqueue(cifsoplockd_wq);
destroy_workqueue(decrypt_wq);
Expand Down
5 changes: 1 addition & 4 deletions fs/cifs/cifsglob.h
Original file line number Diff line number Diff line change
Expand Up @@ -668,9 +668,6 @@ struct TCP_Server_Info {
unsigned int total_read; /* total amount of data read in this pass */
atomic_t in_send; /* requests trying to send */
atomic_t num_waiters; /* blocked waiting to get in sendrecv */
#ifdef CONFIG_CIFS_FSCACHE
struct fscache_cookie *fscache; /* client index cache cookie */
#endif
#ifdef CONFIG_CIFS_STATS2
atomic_t num_cmds[NUMBER_OF_SMB2_COMMANDS]; /* total requests by cmd */
atomic_t smb2slowcmd[NUMBER_OF_SMB2_COMMANDS]; /* count resps > 1 sec */
Expand Down Expand Up @@ -1112,7 +1109,7 @@ struct cifs_tcon {
__u32 max_bytes_copy;
#ifdef CONFIG_CIFS_FSCACHE
u64 resource_id; /* server resource id */
struct fscache_cookie *fscache; /* cookie for share */
struct fscache_volume *fscache; /* cookie for share */
#endif
struct list_head pending_opens; /* list of incomplete opens */
struct cached_fid crfid; /* Cached root fid */
Expand Down
15 changes: 2 additions & 13 deletions fs/cifs/connect.c
Original file line number Diff line number Diff line change
Expand Up @@ -1444,10 +1444,6 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)

cifs_crypto_secmech_release(server);

/* fscache server cookies are based on primary channel only */
if (!CIFS_SERVER_IS_CHAN(server))
cifs_fscache_release_client_cookie(server);

kfree(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
Expand Down Expand Up @@ -1609,14 +1605,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
spin_unlock(&cifs_tcp_ses_lock);

/* fscache server cookies are based on primary channel only */
if (!CIFS_SERVER_IS_CHAN(tcp_ses))
cifs_fscache_get_client_cookie(tcp_ses);
#ifdef CONFIG_CIFS_FSCACHE
else
tcp_ses->fscache = tcp_ses->primary_server->fscache;
#endif /* CONFIG_CIFS_FSCACHE */

/* queue echo request delayed work */
queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);

Expand Down Expand Up @@ -3128,7 +3116,8 @@ static int mount_get_conns(struct mount_ctx *mnt_ctx)
* Inside cifs_fscache_get_super_cookie it checks
* that we do not get super cookie twice.
*/
cifs_fscache_get_super_cookie(tcon);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
cifs_fscache_get_super_cookie(tcon);

out:
mnt_ctx->server = server;
Expand Down
5 changes: 5 additions & 0 deletions fs/cifs/dir.c
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@
#include "cifs_unicode.h"
#include "fs_context.h"
#include "cifs_ioctl.h"
#include "fscache.h"

static void
renew_parental_timestamps(struct dentry *direntry)
Expand Down Expand Up @@ -507,8 +508,12 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
server->ops->close(xid, tcon, &fid);
cifs_del_pending_open(&open);
rc = -ENOMEM;
goto out;
}

fscache_use_cookie(cifs_inode_cookie(file_inode(file)),
file->f_mode & FMODE_WRITE);

out:
cifs_put_tlink(tlink);
out_free_xid:
Expand Down
Loading

0 comments on commit 70431bf

Please sign in to comment.