From 70431bfd825d9cd5d93412c0456f253ecad6c415 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 17 Nov 2020 15:56:59 +0000 Subject: 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,," 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 Acked-by: Jeff Layton cc: Steve French cc: Shyam Prasad N 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 --- fs/cifs/cifsfs.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'fs/cifs/cifsfs.c') diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 36b2e0cb9736..199edac0cb59 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -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); } @@ -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); @@ -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, @@ -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) @@ -1693,8 +1699,6 @@ out_destroy_mids: 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: @@ -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); -- cgit v1.2.3-70-g09d2