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@xxxxxxxxxx> cc: Eric Van Hensbergen <ericvh@xxxxxxxxx> cc: Latchesar Ionkov <lucho@xxxxxxxxxx> cc: Dominique Martinet <asmadeus@xxxxxxxxxxxxx> cc: v9fs-developer@xxxxxxxxxxxxxxxxxxxxx cc: linux-cachefs@xxxxxxxxxx Link: https://lore.kernel.org/r/163819664645.215744.1555314582005286846.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1 Link: https://lore.kernel.org/r/163906975017.143852.3459573173204394039.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v2 --- fs/9p/Kconfig | 2 fs/9p/cache.c | 195 +++++++++--------------------------------------- fs/9p/cache.h | 25 +----- fs/9p/v9fs.c | 17 +--- fs/9p/v9fs.h | 13 +++ fs/9p/vfs_addr.c | 8 +- fs/9p/vfs_dir.c | 13 +++ fs/9p/vfs_file.c | 3 - fs/9p/vfs_inode.c | 22 +++-- fs/9p/vfs_inode_dotl.c | 3 - 10 files changed, 91 insertions(+), 210 deletions(-) diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig index b3d33b3ddb98..d7bc93447c85 100644 --- a/fs/9p/Kconfig +++ b/fs/9p/Kconfig @@ -14,7 +14,7 @@ config 9P_FS if 9P_FS config 9P_FSCACHE bool "Enable 9P client caching support" - depends on 9P_FS=m && FSCACHE_OLD_API || 9P_FS=y && FSCACHE_OLD_API=y + depends on 9P_FS=m && FSCACHE || 9P_FS=y && FSCACHE=y help Choose Y here to enable persistent, read-only local caching support for 9p clients using FS-Cache diff --git a/fs/9p/cache.c b/fs/9p/cache.c index f2ba131cede1..55e108e5e133 100644 --- a/fs/9p/cache.c +++ b/fs/9p/cache.c @@ -16,186 +16,61 @@ #include "v9fs.h" #include "cache.h" -#define CACHETAG_LEN 11 - -struct fscache_netfs v9fs_cache_netfs = { - .name = "9p", - .version = 0, -}; - -/* - * v9fs_random_cachetag - Generate a random tag to be associated - * with a new cache session. - * - * The value of jiffies is used for a fairly randomly cache tag. - */ - -static -int v9fs_random_cachetag(struct v9fs_session_info *v9ses) +int v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses, + const char *dev_name) { - v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL); - if (!v9ses->cachetag) - return -ENOMEM; + struct fscache_volume *vcookie; + char *name, *p; - return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies); -} - -const struct fscache_cookie_def v9fs_cache_session_index_def = { - .name = "9P.session", - .type = FSCACHE_COOKIE_TYPE_INDEX, -}; + name = kasprintf(GFP_KERNEL, "9p,%s,%s", + dev_name, v9ses->cachetag ?: v9ses->aname); + if (!name) + return -ENOMEM; -void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses) -{ - /* If no cache session tag was specified, we generate a random one. */ - if (!v9ses->cachetag) { - if (v9fs_random_cachetag(v9ses) < 0) { - v9ses->fscache = NULL; - kfree(v9ses->cachetag); - v9ses->cachetag = NULL; - return; + for (p = name; *p; p++) + if (*p == '/') + *p = ';'; + + vcookie = fscache_acquire_volume(name, NULL, NULL, 0); + p9_debug(P9_DEBUG_FSC, "session %p get volume %p (%s)\n", + v9ses, vcookie, name); + if (IS_ERR(vcookie)) { + if (vcookie != ERR_PTR(-EBUSY)) { + kfree(name); + return PTR_ERR(vcookie); } + pr_err("Cache volume key already in use (%s)\n", name); + vcookie = NULL; } - - v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index, - &v9fs_cache_session_index_def, - v9ses->cachetag, - strlen(v9ses->cachetag), - NULL, 0, - v9ses, 0, true); - p9_debug(P9_DEBUG_FSC, "session %p get cookie %p\n", - v9ses, v9ses->fscache); -} - -void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses) -{ - p9_debug(P9_DEBUG_FSC, "session %p put cookie %p\n", - v9ses, v9ses->fscache); - fscache_relinquish_cookie(v9ses->fscache, NULL, false); - v9ses->fscache = NULL; -} - -static enum -fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data, - const void *buffer, - uint16_t buflen, - loff_t object_size) -{ - const struct v9fs_inode *v9inode = cookie_netfs_data; - - if (buflen != sizeof(v9inode->qid.version)) - return FSCACHE_CHECKAUX_OBSOLETE; - - if (memcmp(buffer, &v9inode->qid.version, - sizeof(v9inode->qid.version))) - return FSCACHE_CHECKAUX_OBSOLETE; - - return FSCACHE_CHECKAUX_OKAY; + v9ses->fscache = vcookie; + kfree(name); + return 0; } -const struct fscache_cookie_def v9fs_cache_inode_index_def = { - .name = "9p.inode", - .type = FSCACHE_COOKIE_TYPE_DATAFILE, - .check_aux = v9fs_cache_inode_check_aux, -}; - void v9fs_cache_inode_get_cookie(struct inode *inode) { struct v9fs_inode *v9inode; struct v9fs_session_info *v9ses; + __le32 version; + __le64 path; if (!S_ISREG(inode->i_mode)) return; v9inode = V9FS_I(inode); - if (v9inode->fscache) + if (WARN_ON(v9inode->fscache)) return; + version = cpu_to_le32(v9inode->qid.version); + path = cpu_to_le64(v9inode->qid.path); v9ses = v9fs_inode2v9ses(inode); - v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, - &v9fs_cache_inode_index_def, - &v9inode->qid.path, - sizeof(v9inode->qid.path), - &v9inode->qid.version, - sizeof(v9inode->qid.version), - v9inode, - i_size_read(&v9inode->vfs_inode), - true); + v9inode->fscache = + fscache_acquire_cookie(v9fs_session_cache(v9ses), + 0, + &path, sizeof(path), + &version, sizeof(version), + i_size_read(&v9inode->vfs_inode)); p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n", inode, v9inode->fscache); } - -void v9fs_cache_inode_put_cookie(struct inode *inode) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - - if (!v9inode->fscache) - return; - p9_debug(P9_DEBUG_FSC, "inode %p put cookie %p\n", - inode, v9inode->fscache); - - fscache_relinquish_cookie(v9inode->fscache, &v9inode->qid.version, - false); - v9inode->fscache = NULL; -} - -void v9fs_cache_inode_flush_cookie(struct inode *inode) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - - if (!v9inode->fscache) - return; - p9_debug(P9_DEBUG_FSC, "inode %p flush cookie %p\n", - inode, v9inode->fscache); - - fscache_relinquish_cookie(v9inode->fscache, NULL, true); - v9inode->fscache = NULL; -} - -void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - - if (!v9inode->fscache) - return; - - mutex_lock(&v9inode->fscache_lock); - - if ((filp->f_flags & O_ACCMODE) != O_RDONLY) - v9fs_cache_inode_flush_cookie(inode); - else - v9fs_cache_inode_get_cookie(inode); - - mutex_unlock(&v9inode->fscache_lock); -} - -void v9fs_cache_inode_reset_cookie(struct inode *inode) -{ - struct v9fs_inode *v9inode = V9FS_I(inode); - struct v9fs_session_info *v9ses; - struct fscache_cookie *old; - - if (!v9inode->fscache) - return; - - old = v9inode->fscache; - - mutex_lock(&v9inode->fscache_lock); - fscache_relinquish_cookie(v9inode->fscache, NULL, true); - - v9ses = v9fs_inode2v9ses(inode); - v9inode->fscache = fscache_acquire_cookie(v9ses->fscache, - &v9fs_cache_inode_index_def, - &v9inode->qid.path, - sizeof(v9inode->qid.path), - &v9inode->qid.version, - sizeof(v9inode->qid.version), - v9inode, - i_size_read(&v9inode->vfs_inode), - true); - p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n", - inode, old, v9inode->fscache); - - mutex_unlock(&v9inode->fscache_lock); -} diff --git a/fs/9p/cache.h b/fs/9p/cache.h index 7480b4b49fea..1923affcdc62 100644 --- a/fs/9p/cache.h +++ b/fs/9p/cache.h @@ -7,26 +7,15 @@ #ifndef _9P_CACHE_H #define _9P_CACHE_H -#define FSCACHE_USE_NEW_IO_API + #include <linux/fscache.h> #ifdef CONFIG_9P_FSCACHE -extern struct fscache_netfs v9fs_cache_netfs; -extern const struct fscache_cookie_def v9fs_cache_session_index_def; -extern const struct fscache_cookie_def v9fs_cache_inode_index_def; - -extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses); -extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses); +extern int v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses, + const char *dev_name); extern void v9fs_cache_inode_get_cookie(struct inode *inode); -extern void v9fs_cache_inode_put_cookie(struct inode *inode); -extern void v9fs_cache_inode_flush_cookie(struct inode *inode); -extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp); -extern void v9fs_cache_inode_reset_cookie(struct inode *inode); - -extern int __v9fs_cache_register(void); -extern void __v9fs_cache_unregister(void); #else /* CONFIG_9P_FSCACHE */ @@ -34,13 +23,5 @@ static inline void v9fs_cache_inode_get_cookie(struct inode *inode) { } -static inline void v9fs_cache_inode_put_cookie(struct inode *inode) -{ -} - -static inline void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *file) -{ -} - #endif /* CONFIG_9P_FSCACHE */ #endif /* _9P_CACHE_H */ diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index e32dd5f7721b..08f65c40af4f 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -469,7 +469,11 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, #ifdef CONFIG_9P_FSCACHE /* register the session for caching */ - v9fs_cache_session_get_cookie(v9ses); + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) { + rc = v9fs_cache_session_get_cookie(v9ses, dev_name); + if (rc < 0) + goto err_clnt; + } #endif spin_lock(&v9fs_sessionlist_lock); list_add(&v9ses->slist, &v9fs_sessionlist); @@ -502,8 +506,7 @@ void v9fs_session_close(struct v9fs_session_info *v9ses) } #ifdef CONFIG_9P_FSCACHE - if (v9ses->fscache) - v9fs_cache_session_put_cookie(v9ses); + fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false); kfree(v9ses->cachetag); #endif kfree(v9ses->uname); @@ -665,20 +668,12 @@ static int v9fs_cache_register(void) ret = v9fs_init_inode_cache(); if (ret < 0) return ret; -#ifdef CONFIG_9P_FSCACHE - ret = fscache_register_netfs(&v9fs_cache_netfs); - if (ret < 0) - v9fs_destroy_inode_cache(); -#endif return ret; } static void v9fs_cache_unregister(void) { v9fs_destroy_inode_cache(); -#ifdef CONFIG_9P_FSCACHE - fscache_unregister_netfs(&v9fs_cache_netfs); -#endif } /** diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index 1647a8e63671..bc8b30205d36 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -89,7 +89,7 @@ struct v9fs_session_info { unsigned int cache; #ifdef CONFIG_9P_FSCACHE char *cachetag; - struct fscache_cookie *fscache; + struct fscache_volume *fscache; #endif char *uname; /* user name to mount as */ @@ -109,7 +109,6 @@ struct v9fs_session_info { struct v9fs_inode { #ifdef CONFIG_9P_FSCACHE - struct mutex fscache_lock; struct fscache_cookie *fscache; #endif struct p9_qid qid; @@ -133,6 +132,16 @@ static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inod #endif } +static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses) +{ +#ifdef CONFIG_9P_FSCACHE + return v9ses->fscache; +#else + return NULL; +#endif +} + + extern int v9fs_show_options(struct seq_file *m, struct dentry *root); struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 4ea8f862b9e4..4f5ce4aca317 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -76,7 +76,9 @@ static void v9fs_req_cleanup(struct address_space *mapping, void *priv) */ static bool v9fs_is_cache_enabled(struct inode *inode) { - return fscache_cookie_enabled(v9fs_inode_cookie(V9FS_I(inode))); + struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(inode)); + + return fscache_cookie_enabled(cookie) && cookie->cache_priv; } /** @@ -88,7 +90,7 @@ static int v9fs_begin_cache_operation(struct netfs_read_request *rreq) #ifdef CONFIG_9P_FSCACHE struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(rreq->inode)); - return fscache_begin_read_operation(rreq, cookie); + return fscache_begin_read_operation(&rreq->cache_resources, cookie); #else return -ENOBUFS; #endif @@ -140,7 +142,7 @@ static int v9fs_release_page(struct page *page, gfp_t gfp) return 0; #ifdef CONFIG_9P_FSCACHE if (folio_test_fscache(folio)) { - if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS)) + if (!gfpflags_allow_blocking(gfp) || !(gfp & __GFP_FS)) return 0; folio_wait_fscache(folio); } 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; } diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 612e297f3763..be72ad9edb3e 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -93,7 +93,8 @@ int v9fs_file_open(struct inode *inode, struct file *file) } mutex_unlock(&v9inode->v_mutex); if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) - v9fs_cache_inode_set_cookie(inode, file); + fscache_use_cookie(v9fs_inode_cookie(v9inode), + file->f_mode & FMODE_WRITE); v9fs_open_fid_add(inode, fid); return 0; out_error: diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 328c338ff304..00366bf1ac2c 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -233,7 +233,6 @@ struct inode *v9fs_alloc_inode(struct super_block *sb) return NULL; #ifdef CONFIG_9P_FSCACHE v9inode->fscache = NULL; - mutex_init(&v9inode->fscache_lock); #endif v9inode->writeback_fid = NULL; v9inode->cache_validity = 0; @@ -386,7 +385,7 @@ void v9fs_evict_inode(struct inode *inode) clear_inode(inode); filemap_fdatawrite(&inode->i_data); - v9fs_cache_inode_put_cookie(inode); + fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false); /* clunk the fid stashed in writeback_fid */ if (v9inode->writeback_fid) { p9_client_clunk(v9inode->writeback_fid); @@ -869,7 +868,8 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, file->private_data = fid; if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) - v9fs_cache_inode_set_cookie(d_inode(dentry), file); + fscache_use_cookie(v9fs_inode_cookie(v9inode), + file->f_mode & FMODE_WRITE); v9fs_open_fid_add(inode, fid); file->f_mode |= FMODE_CREATED; @@ -1072,6 +1072,8 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, struct iattr *iattr) { int retval, use_dentry = 0; + struct inode *inode = d_inode(dentry); + struct v9fs_inode *v9inode = V9FS_I(inode); struct v9fs_session_info *v9ses; struct p9_fid *fid = NULL; struct p9_wstat wstat; @@ -1117,7 +1119,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns, /* Write all dirty data */ if (d_is_reg(dentry)) - filemap_write_and_wait(d_inode(dentry)->i_mapping); + filemap_write_and_wait(inode->i_mapping); retval = p9_client_wstat(fid, &wstat); @@ -1128,13 +1130,15 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns, return retval; if ((iattr->ia_valid & ATTR_SIZE) && - iattr->ia_size != i_size_read(d_inode(dentry))) - truncate_setsize(d_inode(dentry), iattr->ia_size); + iattr->ia_size != i_size_read(inode)) { + truncate_setsize(inode, iattr->ia_size); + fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size); + } - v9fs_invalidate_inode_attr(d_inode(dentry)); + v9fs_invalidate_inode_attr(inode); - setattr_copy(&init_user_ns, d_inode(dentry), iattr); - mark_inode_dirty(d_inode(dentry)); + setattr_copy(&init_user_ns, inode, iattr); + mark_inode_dirty(inode); return 0; } diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 7dee89ba32e7..cae301d09cd3 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -344,7 +344,8 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, goto err_clunk_old_fid; file->private_data = ofid; if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) - v9fs_cache_inode_set_cookie(inode, file); + fscache_use_cookie(v9fs_inode_cookie(v9inode), + file->f_mode & FMODE_WRITE); v9fs_open_fid_add(inode, ofid); file->f_mode |= FMODE_CREATED; out: -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/linux-cachefs