cifs: Support fscache indexing rewrite
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 <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
cc: Steve French <smfrench@gmail.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: linux-cifs@vger.kernel.org
cc: linux-cachefs@redhat.com
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23b55d673d7527b093cd97b7c217c82e70cd1af0 [1]
Link: https://lore.kernel.org/r/3419813.1641592362@warthog.procyon.org.uk/ [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/3462849.1641593783@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/1318953.1642024578@warthog.procyon.org.uk/ # v6
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index 003c5f1..efaac4d 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -12,250 +12,136 @@
#include "cifs_fs_sb.h"
#include "cifsproto.h"
-/*
- * Key layout of CIFS server cache index object
- */
-struct cifs_server_key {
- __u64 conn_id;
-} __packed;
-
-/*
- * Get a cookie for a server object keyed by {IPaddress,port,family} tuple
- */
-void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
+static void cifs_fscache_fill_volume_coherency(
+ struct cifs_tcon *tcon,
+ struct cifs_fscache_volume_coherency_data *cd)
{
- struct cifs_server_key key;
+ memset(cd, 0, sizeof(*cd));
+ cd->resource_id = cpu_to_le64(tcon->resource_id);
+ cd->vol_create_time = tcon->vol_create_time;
+ cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number);
+}
- /*
- * Check if cookie was already initialized so don't reinitialize it.
- * In the future, as we integrate with newer fscache features,
- * we may want to instead add a check if cookie has changed
- */
- if (server->fscache)
- return;
+int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
+{
+ struct cifs_fscache_volume_coherency_data cd;
+ struct TCP_Server_Info *server = tcon->ses->server;
+ struct fscache_volume *vcookie;
+ const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr;
+ size_t slen, i;
+ char *sharename;
+ char *key;
+ int ret = -ENOMEM;
+
+ tcon->fscache = NULL;
+ switch (sa->sa_family) {
+ case AF_INET:
+ case AF_INET6:
+ break;
+ default:
+ cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
+ return -EINVAL;
+ }
memset(&key, 0, sizeof(key));
- key.conn_id = server->conn_id;
-
- server->fscache =
- fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
- &cifs_fscache_server_index_def,
- &key, sizeof(key),
- NULL, 0,
- server, 0, true);
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
- __func__, server, server->fscache);
-}
-
-void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
-{
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
- __func__, server, server->fscache);
- fscache_relinquish_cookie(server->fscache, NULL, false);
- server->fscache = NULL;
-}
-
-void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
-{
- struct TCP_Server_Info *server = tcon->ses->server;
- char *sharename;
- struct cifs_fscache_super_auxdata auxdata;
-
- /*
- * Check if cookie was already initialized so don't reinitialize it.
- * In the future, as we integrate with newer fscache features,
- * we may want to instead add a check if cookie has changed
- */
- if (tcon->fscache)
- return;
sharename = extract_sharename(tcon->treeName);
if (IS_ERR(sharename)) {
cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
- tcon->fscache = NULL;
- return;
+ return -EINVAL;
}
- memset(&auxdata, 0, sizeof(auxdata));
- auxdata.resource_id = tcon->resource_id;
- auxdata.vol_create_time = tcon->vol_create_time;
- auxdata.vol_serial_number = tcon->vol_serial_number;
+ slen = strlen(sharename);
+ for (i = 0; i < slen; i++)
+ if (sharename[i] == '/')
+ sharename[i] = ';';
- tcon->fscache =
- fscache_acquire_cookie(server->fscache,
- &cifs_fscache_super_index_def,
- sharename, strlen(sharename),
- &auxdata, sizeof(auxdata),
- tcon, 0, true);
+ key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename);
+ if (!key)
+ goto out;
+
+ cifs_fscache_fill_volume_coherency(tcon, &cd);
+ vcookie = fscache_acquire_volume(key,
+ NULL, /* preferred_cache */
+ &cd, sizeof(cd));
+ cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie);
+ if (IS_ERR(vcookie)) {
+ if (vcookie != ERR_PTR(-EBUSY)) {
+ ret = PTR_ERR(vcookie);
+ goto out_2;
+ }
+ pr_err("Cache volume key already in use (%s)\n", key);
+ vcookie = NULL;
+ }
+
+ tcon->fscache = vcookie;
+ ret = 0;
+out_2:
+ kfree(key);
+out:
kfree(sharename);
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
- __func__, server->fscache, tcon->fscache);
+ return ret;
}
void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
{
- struct cifs_fscache_super_auxdata auxdata;
-
- memset(&auxdata, 0, sizeof(auxdata));
- auxdata.resource_id = tcon->resource_id;
- auxdata.vol_create_time = tcon->vol_create_time;
- auxdata.vol_serial_number = tcon->vol_serial_number;
+ struct cifs_fscache_volume_coherency_data cd;
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
- fscache_relinquish_cookie(tcon->fscache, &auxdata, false);
+
+ cifs_fscache_fill_volume_coherency(tcon, &cd);
+ fscache_relinquish_volume(tcon->fscache, &cd, false);
tcon->fscache = NULL;
}
-static void cifs_fscache_acquire_inode_cookie(struct cifsInodeInfo *cifsi,
- struct cifs_tcon *tcon)
+void cifs_fscache_get_inode_cookie(struct inode *inode)
{
- struct cifs_fscache_inode_auxdata auxdata;
-
- memset(&auxdata, 0, sizeof(auxdata));
- auxdata.eof = cifsi->server_eof;
- auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
- auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
- auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
- auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
-
- cifsi->fscache =
- fscache_acquire_cookie(tcon->fscache,
- &cifs_fscache_inode_object_def,
- &cifsi->uniqueid, sizeof(cifsi->uniqueid),
- &auxdata, sizeof(auxdata),
- cifsi, cifsi->vfs_inode.i_size, true);
-}
-
-static void cifs_fscache_enable_inode_cookie(struct inode *inode)
-{
+ struct cifs_fscache_inode_coherency_data cd;
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
- if (cifsi->fscache)
- return;
+ cifs_fscache_fill_coherency(&cifsi->vfs_inode, &cd);
- if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE))
- return;
+ cifsi->fscache =
+ fscache_acquire_cookie(tcon->fscache, 0,
+ &cifsi->uniqueid, sizeof(cifsi->uniqueid),
+ &cd, sizeof(cd),
+ i_size_read(&cifsi->vfs_inode));
+}
- cifs_fscache_acquire_inode_cookie(cifsi, tcon);
+void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update)
+{
+ if (update) {
+ struct cifs_fscache_inode_coherency_data cd;
+ loff_t i_size = i_size_read(inode);
- cifs_dbg(FYI, "%s: got FH cookie (0x%p/0x%p)\n",
- __func__, tcon->fscache, cifsi->fscache);
+ cifs_fscache_fill_coherency(inode, &cd);
+ fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size);
+ } else {
+ fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL);
+ }
}
void cifs_fscache_release_inode_cookie(struct inode *inode)
{
- struct cifs_fscache_inode_auxdata auxdata;
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
- memset(&auxdata, 0, sizeof(auxdata));
- auxdata.eof = cifsi->server_eof;
- auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
- auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
- auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
- auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
-
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
- /* fscache_relinquish_cookie does not seem to update auxdata */
- fscache_update_cookie(cifsi->fscache, &auxdata);
- fscache_relinquish_cookie(cifsi->fscache, &auxdata, false);
+ fscache_relinquish_cookie(cifsi->fscache, false);
cifsi->fscache = NULL;
}
}
-void cifs_fscache_update_inode_cookie(struct inode *inode)
-{
- struct cifs_fscache_inode_auxdata auxdata;
- struct cifsInodeInfo *cifsi = CIFS_I(inode);
-
- if (cifsi->fscache) {
- memset(&auxdata, 0, sizeof(auxdata));
- auxdata.eof = cifsi->server_eof;
- auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
- auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
- auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
- auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
-
- cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
- fscache_update_cookie(cifsi->fscache, &auxdata);
- }
-}
-
-void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
-{
- cifs_fscache_enable_inode_cookie(inode);
-}
-
-void cifs_fscache_reset_inode_cookie(struct inode *inode)
-{
- struct cifsInodeInfo *cifsi = CIFS_I(inode);
- struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
- struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
- struct fscache_cookie *old = cifsi->fscache;
-
- if (cifsi->fscache) {
- /* retire the current fscache cache and get a new one */
- fscache_relinquish_cookie(cifsi->fscache, NULL, true);
-
- cifs_fscache_acquire_inode_cookie(cifsi, tcon);
- cifs_dbg(FYI, "%s: new cookie 0x%p oldcookie 0x%p\n",
- __func__, cifsi->fscache, old);
- }
-}
-
-int cifs_fscache_release_page(struct page *page, gfp_t gfp)
-{
- if (PageFsCache(page)) {
- struct inode *inode = page->mapping->host;
- struct cifsInodeInfo *cifsi = CIFS_I(inode);
-
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
- __func__, page, cifsi->fscache);
- if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
- return 0;
- }
-
- return 1;
-}
-
-static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
- int error)
-{
- cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, page, error);
- if (!error)
- SetPageUptodate(page);
- unlock_page(page);
-}
-
/*
* Retrieve a page from FS-Cache
*/
int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
{
- int ret;
-
cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
__func__, CIFS_I(inode)->fscache, page, inode);
- ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
- cifs_readpage_from_fscache_complete,
- NULL,
- GFP_KERNEL);
- switch (ret) {
-
- case 0: /* page found in fscache, read submitted */
- cifs_dbg(FYI, "%s: submitted\n", __func__);
- return ret;
- case -ENOBUFS: /* page won't be cached */
- case -ENODATA: /* page not in cache */
- cifs_dbg(FYI, "%s: %d\n", __func__, ret);
- return 1;
-
- default:
- cifs_dbg(VFS, "unknown error ret = %d\n", ret);
- }
- return ret;
+ return -ENOBUFS; // Needs conversion to using netfslib
}
/*
@@ -266,78 +152,19 @@ int __cifs_readpages_from_fscache(struct inode *inode,
struct list_head *pages,
unsigned *nr_pages)
{
- int ret;
-
cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
__func__, CIFS_I(inode)->fscache, *nr_pages, inode);
- ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
- pages, nr_pages,
- cifs_readpage_from_fscache_complete,
- NULL,
- mapping_gfp_mask(mapping));
- switch (ret) {
- case 0: /* read submitted to the cache for all pages */
- cifs_dbg(FYI, "%s: submitted\n", __func__);
- return ret;
-
- case -ENOBUFS: /* some pages are not cached and can't be */
- case -ENODATA: /* some pages are not cached */
- cifs_dbg(FYI, "%s: no page\n", __func__);
- return 1;
-
- default:
- cifs_dbg(FYI, "unknown error ret = %d\n", ret);
- }
-
- return ret;
+ return -ENOBUFS; // Needs conversion to using netfslib
}
void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
- int ret;
WARN_ON(!cifsi->fscache);
cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
__func__, cifsi->fscache, page, inode);
- ret = fscache_write_page(cifsi->fscache, page,
- cifsi->vfs_inode.i_size, GFP_KERNEL);
- if (ret != 0)
- fscache_uncache_page(cifsi->fscache, page);
-}
-void __cifs_fscache_readpages_cancel(struct inode *inode, struct list_head *pages)
-{
- cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
- __func__, CIFS_I(inode)->fscache, inode);
- fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
-}
-
-void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
-{
- struct cifsInodeInfo *cifsi = CIFS_I(inode);
- struct fscache_cookie *cookie = cifsi->fscache;
-
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
- fscache_wait_on_page_write(cookie, page);
- fscache_uncache_page(cookie, page);
-}
-
-void __cifs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
-{
- struct cifsInodeInfo *cifsi = CIFS_I(inode);
- struct fscache_cookie *cookie = cifsi->fscache;
-
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
- fscache_wait_on_page_write(cookie, page);
-}
-
-void __cifs_fscache_uncache_page(struct inode *inode, struct page *page)
-{
- struct cifsInodeInfo *cifsi = CIFS_I(inode);
- struct fscache_cookie *cookie = cifsi->fscache;
-
- cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
- fscache_uncache_page(cookie, page);
+ // Needs conversion to using netfslib
}