diff options
| -rw-r--r-- | fs/afs/dir.c | 84 |
1 files changed, 70 insertions, 14 deletions
diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 618e26cea887..81207dc3c997 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -440,7 +440,7 @@ static int afs_dir_iterate_block(struct afs_vnode *dvnode, * iterate through the data blob that lists the contents of an AFS directory */ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx, - struct key *key) + struct key *key, afs_dataversion_t *_dir_version) { struct afs_vnode *dvnode = AFS_FS_I(dir); struct afs_xdr_dir_page *dbuf; @@ -460,6 +460,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx, req = afs_read_dir(dvnode, key); if (IS_ERR(req)) return PTR_ERR(req); + *_dir_version = req->data_version; /* round the file position up to the next entry boundary */ ctx->pos += sizeof(union afs_xdr_dirent) - 1; @@ -514,7 +515,10 @@ out: */ static int afs_readdir(struct file *file, struct dir_context *ctx) { - return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file)); + afs_dataversion_t dir_version; + + return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file), + &dir_version); } /* @@ -555,7 +559,8 @@ static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, * - just returns the FID the dentry name maps to if found */ static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry, - struct afs_fid *fid, struct key *key) + struct afs_fid *fid, struct key *key, + afs_dataversion_t *_dir_version) { struct afs_super_info *as = dir->i_sb->s_fs_info; struct afs_lookup_one_cookie cookie = { @@ -568,7 +573,7 @@ static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry, _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry); /* search the directory */ - ret = afs_dir_iterate(dir, &cookie.ctx, key); + ret = afs_dir_iterate(dir, &cookie.ctx, key, _dir_version); if (ret < 0) { _leave(" = %d [iter]", ret); return ret; @@ -642,6 +647,7 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry, struct afs_server *server; struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode; struct inode *inode = NULL, *ti; + afs_dataversion_t data_version = READ_ONCE(dvnode->status.data_version); int ret, i; _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry); @@ -669,12 +675,14 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry, cookie->fids[i].vid = as->volume->vid; /* search the directory */ - ret = afs_dir_iterate(dir, &cookie->ctx, key); + ret = afs_dir_iterate(dir, &cookie->ctx, key, &data_version); if (ret < 0) { inode = ERR_PTR(ret); goto out; } + dentry->d_fsdata = (void *)(unsigned long)data_version; + inode = ERR_PTR(-ENOENT); if (!cookie->found) goto out; @@ -968,7 +976,8 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) struct dentry *parent; struct inode *inode; struct key *key; - long dir_version, de_version; + afs_dataversion_t dir_version; + long de_version; int ret; if (flags & LOOKUP_RCU) @@ -1014,20 +1023,20 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) * on a 32-bit system, we only have 32 bits in the dentry to store the * version. */ - dir_version = (long)dir->status.data_version; + dir_version = dir->status.data_version; de_version = (long)dentry->d_fsdata; - if (de_version == dir_version) + if (de_version == (long)dir_version) goto out_valid_noupdate; - dir_version = (long)dir->invalid_before; - if (de_version - dir_version >= 0) + dir_version = dir->invalid_before; + if (de_version - (long)dir_version >= 0) goto out_valid; _debug("dir modified"); afs_stat_v(dir, n_reval); /* search the directory for this vnode */ - ret = afs_do_lookup_one(&dir->vfs_inode, dentry, &fid, key); + ret = afs_do_lookup_one(&dir->vfs_inode, dentry, &fid, key, &dir_version); switch (ret) { case 0: /* the filename maps to something */ @@ -1080,7 +1089,7 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) } out_valid: - dentry->d_fsdata = (void *)dir_version; + dentry->d_fsdata = (void *)(unsigned long)dir_version; out_valid_noupdate: dput(parent); key_put(key); @@ -1187,6 +1196,20 @@ static void afs_prep_for_new_inode(struct afs_fs_cursor *fc, } /* + * Note that a dentry got changed. We need to set d_fsdata to the data version + * number derived from the result of the operation. It doesn't matter if + * d_fsdata goes backwards as we'll just revalidate. + */ +static void afs_update_dentry_version(struct afs_fs_cursor *fc, + struct dentry *dentry, + struct afs_status_cb *scb) +{ + if (fc->ac.error == 0) + dentry->d_fsdata = + (void *)(unsigned long)scb->status.data_version; +} + +/* * create a directory on an AFS filesystem */ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) @@ -1228,6 +1251,7 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) afs_check_for_remote_deletion(&fc, dvnode); afs_vnode_commit_status(&fc, dvnode, fc.cb_break, &data_version, &scb[0]); + afs_update_dentry_version(&fc, dentry, &scb[0]); afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]); ret = afs_end_vnode_operation(&fc); if (ret < 0) @@ -1320,6 +1344,7 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry) afs_vnode_commit_status(&fc, dvnode, fc.cb_break, &data_version, scb); + afs_update_dentry_version(&fc, dentry, scb); ret = afs_end_vnode_operation(&fc); if (ret == 0) { afs_dir_remove_subdir(dentry); @@ -1459,6 +1484,7 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry) &data_version, &scb[0]); afs_vnode_commit_status(&fc, vnode, fc.cb_break_2, &data_version_2, &scb[1]); + afs_update_dentry_version(&fc, dentry, &scb[0]); ret = afs_end_vnode_operation(&fc); if (ret == 0 && !(scb[1].have_status || scb[1].have_error)) ret = afs_dir_remove_link(dvnode, dentry, key); @@ -1527,6 +1553,7 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode, afs_check_for_remote_deletion(&fc, dvnode); afs_vnode_commit_status(&fc, dvnode, fc.cb_break, &data_version, &scb[0]); + afs_update_dentry_version(&fc, dentry, &scb[0]); afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]); ret = afs_end_vnode_operation(&fc); if (ret < 0) @@ -1608,6 +1635,7 @@ static int afs_link(struct dentry *from, struct inode *dir, afs_vnode_commit_status(&fc, vnode, fc.cb_break_2, NULL, &scb[1]); ihold(&vnode->vfs_inode); + afs_update_dentry_version(&fc, dentry, &scb[0]); d_instantiate(dentry, &vnode->vfs_inode); mutex_unlock(&vnode->io_lock); @@ -1687,6 +1715,7 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry, afs_check_for_remote_deletion(&fc, dvnode); afs_vnode_commit_status(&fc, dvnode, fc.cb_break, &data_version, &scb[0]); + afs_update_dentry_version(&fc, dentry, &scb[0]); afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]); ret = afs_end_vnode_operation(&fc); if (ret < 0) @@ -1792,6 +1821,17 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, } } + /* This bit is potentially nasty as there's a potential race with + * afs_d_revalidate{,_rcu}(). We have to change d_fsdata on the dentry + * to reflect it's new parent's new data_version after the op, but + * d_revalidate may see old_dentry between the op having taken place + * and the version being updated. + * + * So drop the old_dentry for now to make other threads go through + * lookup instead - which we hold a lock against. + */ + d_drop(old_dentry); + ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, orig_dvnode, key, true)) { afs_dataversion_t orig_data_version; @@ -1803,7 +1843,7 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, if (orig_dvnode != new_dvnode) { if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) { afs_end_vnode_operation(&fc); - goto error_rehash; + goto error_rehash_old; } new_data_version = new_dvnode->status.data_version + 1; } else { @@ -1828,7 +1868,7 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, } ret = afs_end_vnode_operation(&fc); if (ret < 0) - goto error_rehash; + goto error_rehash_old; } if (ret == 0) { @@ -1854,10 +1894,26 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, drop_nlink(new_inode); spin_unlock(&new_inode->i_lock); } + + /* Now we can update d_fsdata on the dentries to reflect their + * new parent's data_version. + * + * Note that if we ever implement RENAME_EXCHANGE, we'll have + * to update both dentries with opposing dir versions. + */ + if (new_dvnode != orig_dvnode) { + afs_update_dentry_version(&fc, old_dentry, &scb[1]); + afs_update_dentry_version(&fc, new_dentry, &scb[1]); + } else { + afs_update_dentry_version(&fc, old_dentry, &scb[0]); + afs_update_dentry_version(&fc, new_dentry, &scb[0]); + } d_move(old_dentry, new_dentry); goto error_tmp; } +error_rehash_old: + d_rehash(new_dentry); error_rehash: if (rehash) d_rehash(rehash); |