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authorDavid Howells <dhowells@redhat.com>2020-11-18 09:06:42 +0000
committerDavid Howells <dhowells@redhat.com>2022-01-10 11:53:06 +0000
commit24e42e32d347f0787a6f99aeb590f3aaa7221093 (patch)
tree99b4c16a4f5cca4c1de96b9ca3ed73c2bd6df875 /fs/9p/vfs_dir.c
parent0770bd4187c555e6df087f7abc252eeacb0842ec (diff)
9p: Use fscache indexing rewrite and reenable caching
Change the 9p filesystem to take account of the changes to fscache's indexing rewrite and reenable caching in 9p. 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 9p, I've made it render the volume name string as: "9p,<devname>,<cachetag>" where the cachetag is replaced by the aname if it wasn't supplied. This probably needs rethinking a bit as the aname can have slashes in it. It might be better to hash the cachetag and use the hash or I could substitute commas for the slashes or something. (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/flush 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) wait_on_page_bit[_killable]() is replaced with the specific wait functions for the bits waited upon. (6) I've got rid of some of the 9p-specific cache helper functions and called things like fscache_relinquish_cookie() directly as they'll optimise away if v9fs_inode_cookie() returns an unconditional NULL (which will be the case if CONFIG_9P_FSCACHE=n). (7) v9fs_vfs_setattr() is made to call fscache_resize() to change the size of the cache object. Notes: (A) We should call fscache_invalidate() if we detect that the server's copy of a file got changed by a third party, but I don't know where to do that. We don't need to do that when allocating the cookie as we get a check-and-invalidate when we initially bind to the cache object. (B) The copy-to-cache-on-writeback side of things will be handled in separate patch. Changes ======= ver #3: - Canonicalise the cookie key and coherency data to make them endianness-independent. ver #2: - Use gfpflags_allow_blocking() rather than using flag directly. - fscache_acquire_volume() now returns errors. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dominique Martinet <asmadeus@codewreck.org> cc: Eric Van Hensbergen <ericvh@gmail.com> cc: Latchesar Ionkov <lucho@ionkov.net> cc: v9fs-developer@lists.sourceforge.net cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819664645.215744.1555314582005286846.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906975017.143852.3459573173204394039.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967178512.1823006.17377493641569138183.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021573143.640689.3977487095697717967.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/9p/vfs_dir.c')
-rw-r--r--fs/9p/vfs_dir.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 8c854d8cb0cd..958680f7f23e 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -17,6 +17,7 @@
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/uio.h>
+#include <linux/fscache.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
@@ -205,7 +206,10 @@ static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
int v9fs_dir_release(struct inode *inode, struct file *filp)
{
+ struct v9fs_inode *v9inode = V9FS_I(inode);
struct p9_fid *fid;
+ __le32 version;
+ loff_t i_size;
fid = filp->private_data;
p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n",
@@ -216,6 +220,15 @@ int v9fs_dir_release(struct inode *inode, struct file *filp)
spin_unlock(&inode->i_lock);
p9_client_clunk(fid);
}
+
+ if ((filp->f_mode & FMODE_WRITE)) {
+ version = cpu_to_le32(v9inode->qid.version);
+ i_size = i_size_read(inode);
+ fscache_unuse_cookie(v9fs_inode_cookie(v9inode),
+ &version, &i_size);
+ } else {
+ fscache_unuse_cookie(v9fs_inode_cookie(v9inode), NULL, NULL);
+ }
return 0;
}