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/fscache.h | 128 +++++++++++++++++++----------------------------------- 1 file changed, 45 insertions(+), 83 deletions(-) (limited to 'fs/cifs/fscache.h') diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h index 9baa1d0f22bd..c6ca49ac33d4 100644 --- a/fs/cifs/fscache.h +++ b/fs/cifs/fscache.h @@ -13,84 +13,71 @@ #include "cifsglob.h" -#ifdef CONFIG_CIFS_FSCACHE - /* - * Auxiliary data attached to CIFS superblock within the cache + * Coherency data attached to CIFS volume within the cache */ -struct cifs_fscache_super_auxdata { - u64 resource_id; /* unique server resource id */ +struct cifs_fscache_volume_coherency_data { + __le64 resource_id; /* unique server resource id */ __le64 vol_create_time; - u32 vol_serial_number; + __le32 vol_serial_number; } __packed; /* - * Auxiliary data attached to CIFS inode within the cache + * Coherency data attached to CIFS inode within the cache. */ -struct cifs_fscache_inode_auxdata { - u64 last_write_time_sec; - u64 last_change_time_sec; - u32 last_write_time_nsec; - u32 last_change_time_nsec; - u64 eof; +struct cifs_fscache_inode_coherency_data { + __le64 last_write_time_sec; + __le64 last_change_time_sec; + __le32 last_write_time_nsec; + __le32 last_change_time_nsec; }; -/* - * cache.c - */ -extern struct fscache_netfs cifs_fscache_netfs; -extern const struct fscache_cookie_def cifs_fscache_server_index_def; -extern const struct fscache_cookie_def cifs_fscache_super_index_def; -extern const struct fscache_cookie_def cifs_fscache_inode_object_def; - -extern int cifs_fscache_register(void); -extern void cifs_fscache_unregister(void); +#ifdef CONFIG_CIFS_FSCACHE /* * fscache.c */ -extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *); -extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *); -extern void cifs_fscache_get_super_cookie(struct cifs_tcon *); +extern int cifs_fscache_get_super_cookie(struct cifs_tcon *); extern void cifs_fscache_release_super_cookie(struct cifs_tcon *); +extern void cifs_fscache_get_inode_cookie(struct inode *inode); extern void cifs_fscache_release_inode_cookie(struct inode *); -extern void cifs_fscache_update_inode_cookie(struct inode *inode); -extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *); -extern void cifs_fscache_reset_inode_cookie(struct inode *); +extern void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update); + +static inline +void cifs_fscache_fill_coherency(struct inode *inode, + struct cifs_fscache_inode_coherency_data *cd) +{ + struct cifsInodeInfo *cifsi = CIFS_I(inode); + + memset(cd, 0, sizeof(*cd)); + cd->last_write_time_sec = cpu_to_le64(cifsi->vfs_inode.i_mtime.tv_sec); + cd->last_write_time_nsec = cpu_to_le32(cifsi->vfs_inode.i_mtime.tv_nsec); + cd->last_change_time_sec = cpu_to_le64(cifsi->vfs_inode.i_ctime.tv_sec); + cd->last_change_time_nsec = cpu_to_le32(cifsi->vfs_inode.i_ctime.tv_nsec); +} + -extern void __cifs_fscache_invalidate_page(struct page *, struct inode *); -extern void __cifs_fscache_wait_on_page_write(struct inode *inode, struct page *page); -extern void __cifs_fscache_uncache_page(struct inode *inode, struct page *page); extern int cifs_fscache_release_page(struct page *page, gfp_t gfp); extern int __cifs_readpage_from_fscache(struct inode *, struct page *); extern int __cifs_readpages_from_fscache(struct inode *, struct address_space *, struct list_head *, unsigned *); -extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *); - extern void __cifs_readpage_to_fscache(struct inode *, struct page *); -static inline void cifs_fscache_invalidate_page(struct page *page, - struct inode *inode) +static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { - if (PageFsCache(page)) - __cifs_fscache_invalidate_page(page, inode); + return CIFS_I(inode)->fscache; } -static inline void cifs_fscache_wait_on_page_write(struct inode *inode, - struct page *page) +static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) { - if (PageFsCache(page)) - __cifs_fscache_wait_on_page_write(inode, page); -} + struct cifs_fscache_inode_coherency_data cd; -static inline void cifs_fscache_uncache_page(struct inode *inode, - struct page *page) -{ - if (PageFsCache(page)) - __cifs_fscache_uncache_page(inode, page); + cifs_fscache_fill_coherency(inode, &cd); + fscache_invalidate(cifs_inode_cookie(inode), &cd, + i_size_read(inode), flags); } static inline int cifs_readpage_from_fscache(struct inode *inode, @@ -120,41 +107,21 @@ static inline void cifs_readpage_to_fscache(struct inode *inode, __cifs_readpage_to_fscache(inode, page); } -static inline void cifs_fscache_readpages_cancel(struct inode *inode, - struct list_head *pages) +#else /* CONFIG_CIFS_FSCACHE */ +static inline +void cifs_fscache_fill_coherency(struct inode *inode, + struct cifs_fscache_inode_coherency_data *cd) { - if (CIFS_I(inode)->fscache) - return __cifs_fscache_readpages_cancel(inode, pages); } -#else /* CONFIG_CIFS_FSCACHE */ -static inline int cifs_fscache_register(void) { return 0; } -static inline void cifs_fscache_unregister(void) {} - -static inline void -cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {} -static inline void -cifs_fscache_release_client_cookie(struct TCP_Server_Info *server) {} -static inline void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) {} -static inline void -cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {} +static inline int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) { return 0; } +static inline void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {} +static inline void cifs_fscache_get_inode_cookie(struct inode *inode) {} static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {} -static inline void cifs_fscache_update_inode_cookie(struct inode *inode) {} -static inline void cifs_fscache_set_inode_cookie(struct inode *inode, - struct file *filp) {} -static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {} -static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp) -{ - return 1; /* May release page */ -} - -static inline void cifs_fscache_invalidate_page(struct page *page, - struct inode *inode) {} -static inline void cifs_fscache_wait_on_page_write(struct inode *inode, - struct page *page) {} -static inline void cifs_fscache_uncache_page(struct inode *inode, - struct page *page) {} +static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {} +static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; } +static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {} static inline int cifs_readpage_from_fscache(struct inode *inode, struct page *page) @@ -173,11 +140,6 @@ static inline int cifs_readpages_from_fscache(struct inode *inode, static inline void cifs_readpage_to_fscache(struct inode *inode, struct page *page) {} -static inline void cifs_fscache_readpages_cancel(struct inode *inode, - struct list_head *pages) -{ -} - #endif /* CONFIG_CIFS_FSCACHE */ #endif /* _CIFS_FSCACHE_H */ -- cgit v1.2.3