Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758954AbZCPHZm (ORCPT ); Mon, 16 Mar 2009 03:25:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757264AbZCPHXK (ORCPT ); Mon, 16 Mar 2009 03:23:10 -0400 Received: from vsmtp01.dti.ne.jp ([202.216.231.136]:35644 "EHLO vsmtp01.dti.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756594AbZCPHWz (ORCPT ); Mon, 16 Mar 2009 03:22:55 -0400 From: "J. R. Okajima" To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, "J. R. Okajima" Subject: [RFC Aufs2 #2 16/28] aufs dentry and lookup Date: Mon, 16 Mar 2009 16:20:28 +0900 Message-Id: <1237188040-11404-17-git-send-email-hooanon05@yahoo.co.jp> X-Mailer: git-send-email 1.6.1.284.g5dc13 In-Reply-To: <1237188040-11404-1-git-send-email-hooanon05@yahoo.co.jp> References: <1237188040-11404-1-git-send-email-hooanon05@yahoo.co.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 36208 Lines: 1461 initial commit dentry operations and private data Signed-off-by: J. R. Okajima --- fs/aufs/dentry.c | 858 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/aufs/dentry.h | 213 ++++++++++++++ fs/aufs/dinfo.c | 351 ++++++++++++++++++++++ 3 files changed, 1422 insertions(+), 0 deletions(-) create mode 100644 fs/aufs/dentry.c create mode 100644 fs/aufs/dentry.h create mode 100644 fs/aufs/dinfo.c diff --git a/fs/aufs/dentry.c b/fs/aufs/dentry.c new file mode 100644 index 0000000..da4fc58 --- /dev/null +++ b/fs/aufs/dentry.c @@ -0,0 +1,858 @@ +/* + * Copyright (C) 2005-2009 Junjiro R. Okajima + * + * This program, aufs is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +/* + * lookup and dentry operations + */ + +#include "aufs.h" + +static void au_h_nd(struct nameidata *h_nd, struct nameidata *nd) +{ + if (nd) { + *h_nd = *nd; + + /* + * gave up supporting LOOKUP_CREATE/OPEN for lower fs, + * due to whiteout and branch permission. + */ + h_nd->flags &= ~(/*LOOKUP_PARENT |*/ LOOKUP_OPEN | LOOKUP_CREATE + | LOOKUP_FOLLOW); + /* unnecessary? */ + h_nd->intent.open.file = NULL; + } else + memset(h_nd, 0, sizeof(*h_nd)); +} + +struct au_lkup_one_args { + struct dentry **errp; + struct qstr *name; + struct dentry *h_parent; + struct au_branch *br; + struct nameidata *nd; +}; + +struct dentry *au_lkup_one(struct qstr *name, struct dentry *h_parent, + struct au_branch *br, struct nameidata *nd) +{ + struct dentry *h_dentry; + int err; + struct nameidata h_nd; + + if (au_test_fs_null_nd(h_parent->d_sb)) + return vfsub_lookup_one_len(name->name, h_parent, name->len); + + au_h_nd(&h_nd, nd); + h_nd.path.dentry = h_parent; + h_nd.path.mnt = br->br_mnt; + + err = __lookup_one_len(name->name, &h_nd.last, NULL, name->len); + h_dentry = ERR_PTR(err); + if (!err) { + path_get(&h_nd.path); + h_dentry = vfsub_lookup_hash(&h_nd); + path_put(&h_nd.path); + } + + return h_dentry; +} + +static void au_call_lkup_one(void *args) +{ + struct au_lkup_one_args *a = args; + *a->errp = au_lkup_one(a->name, a->h_parent, a->br, a->nd); +} + +#define AuLkup_ALLOW_NEG 1 +#define au_ftest_lkup(flags, name) ((flags) & AuLkup_##name) +#define au_fset_lkup(flags, name) { (flags) |= AuLkup_##name; } +#define au_fclr_lkup(flags, name) { (flags) &= ~AuLkup_##name; } + +struct au_do_lookup_args { + unsigned int flags; + mode_t type; + struct nameidata *nd; +}; + +/* + * returns positive/negative dentry, NULL or an error. + * NULL means whiteout-ed or not-found. + */ +static struct dentry* +au_do_lookup(struct dentry *h_parent, struct dentry *dentry, + aufs_bindex_t bindex, struct qstr *wh_name, + struct au_do_lookup_args *args) +{ + struct dentry *h_dentry; + struct inode *h_inode, *inode; + struct qstr *name; + struct au_branch *br; + int wh_found, opq; + unsigned char wh_able; + const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG); + + name = &dentry->d_name; + wh_found = 0; + br = au_sbr(dentry->d_sb, bindex); + wh_able = !!au_br_whable(br->br_perm); + if (wh_able) + wh_found = au_wh_test(h_parent, wh_name, br, /*try_sio*/0); + h_dentry = ERR_PTR(wh_found); + if (!wh_found) + goto real_lookup; + if (unlikely(wh_found < 0)) + goto out; + + /* We found a whiteout */ + /* au_set_dbend(dentry, bindex); */ + au_set_dbwh(dentry, bindex); + if (!allow_neg) + return NULL; /* success */ + + real_lookup: + h_dentry = au_lkup_one(name, h_parent, br, args->nd); + if (IS_ERR(h_dentry)) + goto out; + + h_inode = h_dentry->d_inode; + if (!h_inode) { + if (!allow_neg) + goto out_neg; + } else if (wh_found + || (args->type && args->type != (h_inode->i_mode & S_IFMT))) + goto out_neg; + + if (au_dbend(dentry) <= bindex) + au_set_dbend(dentry, bindex); + if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry)) + au_set_dbstart(dentry, bindex); + au_set_h_dptr(dentry, bindex, h_dentry); + + inode = dentry->d_inode; + if (!h_inode || !S_ISDIR(h_inode->i_mode) || !wh_able + || (inode && !S_ISDIR(inode->i_mode))) + goto out; /* success */ + + mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD); + opq = au_diropq_test(h_dentry, br); + mutex_unlock(&h_inode->i_mutex); + if (opq > 0) + au_set_dbdiropq(dentry, bindex); + else if (unlikely(opq < 0)) { + au_set_h_dptr(dentry, bindex, NULL); + h_dentry = ERR_PTR(opq); + } + goto out; + + out_neg: + dput(h_dentry); + h_dentry = NULL; + out: + return h_dentry; +} + +/* + * returns the number of lower positive dentries, + * otherwise an error. + * can be called at unlinking with @type is zero. + */ +int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type, + struct nameidata *nd) +{ + int npositive, err; + aufs_bindex_t bindex, btail, bdiropq; + unsigned char isdir; + struct qstr whname; + struct au_do_lookup_args args = { + .flags = 0, + .type = type, + .nd = nd + }; + const struct qstr *name = &dentry->d_name; + struct dentry *parent; + struct inode *inode; + + err = -EPERM; + parent = dget_parent(dentry); + if (unlikely(!strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN))) + goto out; + + err = au_wh_name_alloc(&whname, name); + if (unlikely(err)) + goto out; + + inode = dentry->d_inode; + isdir = !!(inode && S_ISDIR(inode->i_mode)); + if (!type) + au_fset_lkup(args.flags, ALLOW_NEG); + + npositive = 0; + btail = au_dbtaildir(parent); + for (bindex = bstart; bindex <= btail; bindex++) { + struct dentry *h_parent, *h_dentry; + struct inode *h_inode, *h_dir; + + h_dentry = au_h_dptr(dentry, bindex); + if (h_dentry) { + if (h_dentry->d_inode) + npositive++; + if (type != S_IFDIR) + break; + continue; + } + h_parent = au_h_dptr(parent, bindex); + if (!h_parent) + continue; + h_dir = h_parent->d_inode; + if (!h_dir || !S_ISDIR(h_dir->i_mode)) + continue; + + mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT); + h_dentry = au_do_lookup(h_parent, dentry, bindex, &whname, + &args); + mutex_unlock(&h_dir->i_mutex); + err = PTR_ERR(h_dentry); + if (IS_ERR(h_dentry)) + goto out_wh; + au_fclr_lkup(args.flags, ALLOW_NEG); + + if (au_dbwh(dentry) >= 0) + break; + if (!h_dentry) + continue; + h_inode = h_dentry->d_inode; + if (!h_inode) + continue; + npositive++; + if (!args.type) + args.type = h_inode->i_mode & S_IFMT; + if (args.type != S_IFDIR) + break; + else if (isdir) { + /* the type of lower may be different */ + bdiropq = au_dbdiropq(dentry); + if (bdiropq >= 0 && bdiropq <= bindex) + break; + } + } + + if (npositive) { + AuLabel(positive); + au_update_dbstart(dentry); + } + err = npositive; + if (unlikely(!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE) + && au_dbstart(dentry) < 0)) + /* both of real entry and whiteout found */ + err = -EIO; + + out_wh: + kfree(whname.name); + out: + dput(parent); + return err; +} + +struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent, + struct au_branch *br) +{ + struct dentry *dentry; + int wkq_err; + + if (!au_test_h_perm_sio(parent->d_inode, MAY_EXEC)) + dentry = au_lkup_one(name, parent, br, /*nd*/NULL); + else { + struct au_lkup_one_args args = { + .errp = &dentry, + .name = name, + .h_parent = parent, + .br = br, + .nd = NULL + }; + + wkq_err = au_wkq_wait(au_call_lkup_one, &args); + if (unlikely(wkq_err)) + dentry = ERR_PTR(wkq_err); + } + + return dentry; +} + +/* + * lookup @dentry on @bindex which should be negative. + */ +int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex) +{ + int err; + struct dentry *parent, *h_parent, *h_dentry; + struct qstr *name; + + name = &dentry->d_name; + parent = dget_parent(dentry); + h_parent = au_h_dptr(parent, bindex); + h_dentry = au_sio_lkup_one(name, h_parent, + au_sbr(dentry->d_sb, bindex)); + err = PTR_ERR(h_dentry); + if (IS_ERR(h_dentry)) + goto out; + if (unlikely(h_dentry->d_inode)) { + err = -EIO; + AuIOErr("b%d %.*s should be negative.\n", + bindex, AuDLNPair(h_dentry)); + dput(h_dentry); + goto out; + } + + if (bindex < au_dbstart(dentry)) + au_set_dbstart(dentry, bindex); + if (au_dbend(dentry) < bindex) + au_set_dbend(dentry, bindex); + au_set_h_dptr(dentry, bindex, h_dentry); + err = 0; + + out: + dput(parent); + return err; +} + +/* ---------------------------------------------------------------------- */ + +/* subset of struct inode */ +struct au_iattr { + unsigned long i_ino; + /* unsigned int i_nlink; */ + uid_t i_uid; + gid_t i_gid; + u64 i_version; +/* + loff_t i_size; + blkcnt_t i_blocks; +*/ + umode_t i_mode; +}; + +static void au_iattr_save(struct au_iattr *ia, struct inode *h_inode) +{ + ia->i_ino = h_inode->i_ino; + /* ia->i_nlink = h_inode->i_nlink; */ + ia->i_uid = h_inode->i_uid; + ia->i_gid = h_inode->i_gid; + ia->i_version = h_inode->i_version; +/* + ia->i_size = h_inode->i_size; + ia->i_blocks = h_inode->i_blocks; +*/ + ia->i_mode = (h_inode->i_mode & S_IFMT); +} + +static int au_iattr_test(struct au_iattr *ia, struct inode *h_inode) +{ + return ia->i_ino != h_inode->i_ino + /* || ia->i_nlink != h_inode->i_nlink */ + || ia->i_uid != h_inode->i_uid + || ia->i_gid != h_inode->i_gid + || ia->i_version != h_inode->i_version +/* + || ia->i_size != h_inode->i_size + || ia->i_blocks != h_inode->i_blocks +*/ + || ia->i_mode != (h_inode->i_mode & S_IFMT); +} + +static int au_h_verify_dentry(struct dentry *h_dentry, struct dentry *h_parent, + struct au_branch *br) +{ + int err; + struct au_iattr ia; + struct dentry *h_d; + struct inode *h_inode; + struct super_block *h_sb; + + err = 0; + memset(&ia, -1, sizeof(ia)); + h_sb = h_dentry->d_sb; + h_inode = h_dentry->d_inode; + if (h_inode) + au_iattr_save(&ia, h_dentry->d_inode); + else if (au_test_nfs(h_sb) || au_test_fuse(h_sb)) + /* nfs d_revalidate may return 0 for negative dentry */ + /* fuse d_revalidate always return 0 for negative dentry */ + goto out; + + /* main purpose is namei.c:cached_lookup() and d_revalidate */ + h_d = au_lkup_one(&h_dentry->d_name, h_parent, br, /*nd*/NULL); + err = PTR_ERR(h_d); + if (IS_ERR(h_d)) + goto out; + + err = 0; + if (unlikely(h_d != h_dentry + || h_d->d_inode != h_inode + || (h_inode && au_iattr_test(&ia, h_inode)))) + err = -EBUSY; + dput(h_d); + + out: + AuTraceErr(err); + return err; +} + +int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir, + struct dentry *h_parent, struct au_branch *br) +{ + int err; + + err = 0; + if (udba == AuOpt_UDBA_REVAL) { + IMustLock(h_dir); + err = (h_dentry->d_parent->d_inode != h_dir); + } else if (udba == AuOpt_UDBA_HINOTIFY) + err = au_h_verify_dentry(h_dentry, h_parent, br); + + return err; +} + +/* ---------------------------------------------------------------------- */ + +static void au_do_refresh_hdentry(struct au_hdentry *p, struct au_dinfo *dinfo, + struct dentry *parent) +{ + struct dentry *h_d, *h_dp; + struct au_hdentry tmp, *q; + struct super_block *sb; + aufs_bindex_t new_bindex, bindex, bend, bwh, bdiropq; + + bend = dinfo->di_bend; + bwh = dinfo->di_bwh; + bdiropq = dinfo->di_bdiropq; + for (bindex = dinfo->di_bstart; bindex <= bend; bindex++, p++) { + h_d = p->hd_dentry; + if (!h_d) + continue; + + h_dp = dget_parent(h_d); + if (h_dp == au_h_dptr(parent, bindex)) { + dput(h_dp); + continue; + } + + new_bindex = au_find_dbindex(parent, h_dp); + dput(h_dp); + if (dinfo->di_bwh == bindex) + bwh = new_bindex; + if (dinfo->di_bdiropq == bindex) + bdiropq = new_bindex; + if (new_bindex < 0) { + au_hdput(p); + p->hd_dentry = NULL; + continue; + } + + /* swap two lower dentries, and loop again */ + q = dinfo->di_hdentry + new_bindex; + tmp = *q; + *q = *p; + *p = tmp; + if (tmp.hd_dentry) { + bindex--; + p--; + } + } + + sb = parent->d_sb; + dinfo->di_bwh = -1; + if (bwh >= 0 && bwh <= au_sbend(sb) && au_sbr_whable(sb, bwh)) + dinfo->di_bwh = bwh; + + dinfo->di_bdiropq = -1; + if (bdiropq >= 0 + && bdiropq <= au_sbend(sb) + && au_sbr_whable(sb, bdiropq)) + dinfo->di_bdiropq = bdiropq; + + bend = au_dbend(parent); + p = dinfo->di_hdentry; + for (bindex = 0; bindex <= bend; bindex++, p++) + if (p->hd_dentry) { + dinfo->di_bstart = bindex; + break; + } + + p = dinfo->di_hdentry + bend; + for (bindex = bend; bindex >= 0; bindex--, p--) + if (p->hd_dentry) { + dinfo->di_bend = bindex; + break; + } +} + +/* + * returns the number of found lower positive dentries, + * otherwise an error. + */ +int au_refresh_hdentry(struct dentry *dentry, mode_t type) +{ + int npositive, err; + unsigned int sigen; + aufs_bindex_t bstart; + struct au_dinfo *dinfo; + struct super_block *sb; + struct dentry *parent; + + sb = dentry->d_sb; + AuDebugOn(IS_ROOT(dentry)); + sigen = au_sigen(sb); + parent = dget_parent(dentry); + AuDebugOn(au_digen(parent) != sigen + || au_iigen(parent->d_inode) != sigen); + + dinfo = au_di(dentry); + err = au_di_realloc(dinfo, au_sbend(sb) + 1); + npositive = err; + if (unlikely(err)) + goto out; + au_do_refresh_hdentry(dinfo->di_hdentry + dinfo->di_bstart, dinfo, + parent); + + npositive = 0; + bstart = au_dbstart(parent); + if (type != S_IFDIR && dinfo->di_bstart == bstart) + goto out_dgen; /* success */ + + npositive = au_lkup_dentry(dentry, bstart, type, /*nd*/NULL); + if (npositive < 0) + goto out; + if (dinfo->di_bwh >= 0 && dinfo->di_bwh <= dinfo->di_bstart) + d_drop(dentry); + + out_dgen: + au_update_digen(dentry); + out: + dput(parent); + AuTraceErr(npositive); + return npositive; +} + +static noinline_for_stack +int au_do_h_d_reval(struct dentry *h_dentry, struct nameidata *nd, + struct dentry *dentry, aufs_bindex_t bindex) +{ + int err, valid; + int (*reval)(struct dentry *, struct nameidata *); + + err = 0; + reval = NULL; + if (h_dentry->d_op) + reval = h_dentry->d_op->d_revalidate; + if (!reval) + goto out; + + AuDbg("b%d\n", bindex); + if (au_test_fs_null_nd(h_dentry->d_sb)) + /* it may return tri-state */ + valid = reval(h_dentry, NULL); + else { + struct nameidata h_nd; + int locked; + struct dentry *parent; + + au_h_nd(&h_nd, nd); + parent = nd->path.dentry; + locked = (nd && nd->path.dentry != dentry); + if (locked) + di_read_lock_parent(parent, AuLock_IR); + BUG_ON(bindex > au_dbend(parent)); + h_nd.path.dentry = au_h_dptr(parent, bindex); + BUG_ON(!h_nd.path.dentry); + h_nd.path.mnt = au_sbr(parent->d_sb, bindex)->br_mnt; + path_get(&h_nd.path); + valid = reval(h_dentry, &h_nd); + path_put(&h_nd.path); + if (locked) + di_read_unlock(parent, AuLock_IR); + } + + if (unlikely(valid < 0)) + err = valid; + else if (!valid) + err = -EINVAL; + + out: + AuTraceErr(err); + return err; +} + +/* todo: remove this */ +static int h_d_revalidate(struct dentry *dentry, struct inode *inode, + struct nameidata *nd, int do_udba) +{ + int err; + umode_t mode, h_mode; + aufs_bindex_t bindex, btail, bstart, ibs, ibe; + unsigned char plus, unhashed, is_root, h_plus; + struct inode *first, *h_inode, *h_cached_inode; + struct dentry *h_dentry; + struct qstr *name, *h_name; + + err = 0; + plus = 0; + mode = 0; + first = NULL; + ibs = -1; + ibe = -1; + unhashed = !!d_unhashed(dentry); + is_root = !!IS_ROOT(dentry); + name = &dentry->d_name; + + /* + * Theoretically, REVAL test should be unnecessary in case of INOTIFY. + * But inotify doesn't fire some necessary events, + * IN_ATTRIB for atime/nlink/pageio + * IN_DELETE for NFS dentry + * Let's do REVAL test too. + */ + if (do_udba && inode) { + mode = (inode->i_mode & S_IFMT); + plus = (inode->i_nlink > 0); + first = au_h_iptr(inode, au_ibstart(inode)); + ibs = au_ibstart(inode); + ibe = au_ibend(inode); + } + + bstart = au_dbstart(dentry); + btail = bstart; + if (inode && S_ISDIR(inode->i_mode)) + btail = au_dbtaildir(dentry); + for (bindex = bstart; bindex <= btail; bindex++) { + h_dentry = au_h_dptr(dentry, bindex); + if (!h_dentry) + continue; + + AuDbg("b%d, %.*s\n", bindex, AuDLNPair(h_dentry)); + h_name = &h_dentry->d_name; + if (unlikely(do_udba + && !is_root + && (unhashed != !!d_unhashed(h_dentry) + || name->len != h_name->len + || memcmp(name->name, h_name->name, name->len)) + )) { + AuDbg("unhash 0x%x 0x%x, %.*s %.*s\n", + unhashed, d_unhashed(h_dentry), + AuDLNPair(dentry), AuDLNPair(h_dentry)); + goto err; + } + + err = au_do_h_d_reval(h_dentry, nd, dentry, bindex); + if (unlikely(err)) + /* do not goto err, to keep the errno */ + break; + + /* todo: plink too? */ + if (!do_udba) + continue; + + /* UDBA tests */ + h_inode = h_dentry->d_inode; + if (unlikely(!!inode != !!h_inode)) + goto err; + + h_plus = plus; + h_mode = mode; + h_cached_inode = h_inode; + if (h_inode) { + h_mode = (h_inode->i_mode & S_IFMT); + h_plus = (h_inode->i_nlink > 0); + } + if (inode && ibs <= bindex && bindex <= ibe) + h_cached_inode = au_h_iptr(inode, bindex); + + if (unlikely(plus != h_plus + || mode != h_mode + || h_cached_inode != h_inode)) + goto err; + continue; + + err: + err = -EINVAL; + break; + } + + return err; +} + +static int simple_reval_dpath(struct dentry *dentry, unsigned int sigen) +{ + int err; + struct dentry *parent; + struct inode *inode; + + inode = dentry->d_inode; + if (au_digen(dentry) == sigen && au_iigen(inode) == sigen) + return 0; + + parent = dget_parent(dentry); + di_read_lock_parent(parent, AuLock_IR); + AuDebugOn(au_digen(parent) != sigen + || au_iigen(parent->d_inode) != sigen); + au_dbg_verify_gen(parent, sigen); + + /* returns a number of positive dentries */ + err = au_refresh_hdentry(dentry, inode->i_mode & S_IFMT); + if (err >= 0) + err = au_refresh_hinode(inode, dentry); + + di_read_unlock(parent, AuLock_IR); + dput(parent); + return err; +} + +int au_reval_dpath(struct dentry *dentry, unsigned int sigen) +{ + int err; + struct dentry *d, *parent; + struct inode *inode; + + if (!au_ftest_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIRS)) + return simple_reval_dpath(dentry, sigen); + + /* slow loop, keep it simple and stupid */ + /* cf: au_cpup_dirs() */ + err = 0; + parent = NULL; + while (au_digen(dentry) != sigen + || au_iigen(dentry->d_inode) != sigen) { + d = dentry; + while (1) { + dput(parent); + parent = dget_parent(d); + if (au_digen(parent) == sigen + && au_iigen(parent->d_inode) == sigen) + break; + d = parent; + } + + inode = d->d_inode; + if (d != dentry) + di_write_lock_child(d); + + /* someone might update our dentry while we were sleeping */ + if (au_digen(d) != sigen || au_iigen(d->d_inode) != sigen) { + di_read_lock_parent(parent, AuLock_IR); + /* returns a number of positive dentries */ + err = au_refresh_hdentry(d, inode->i_mode & S_IFMT); + if (err >= 0) + err = au_refresh_hinode(inode, d); + di_read_unlock(parent, AuLock_IR); + } + + if (d != dentry) + di_write_unlock(d); + dput(parent); + if (unlikely(err)) + break; + } + + return err; +} + +/* + * if valid returns 1, otherwise 0. + */ +static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + int valid, err; + unsigned int sigen; + unsigned char do_udba; + struct super_block *sb; + struct inode *inode; + + err = -EINVAL; + sb = dentry->d_sb; + inode = dentry->d_inode; + aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW); + sigen = au_sigen(sb); + if (au_digen(dentry) != sigen) { + AuDebugOn(IS_ROOT(dentry)); + if (inode) + err = au_reval_dpath(dentry, sigen); + if (unlikely(err)) + goto out_dgrade; + AuDebugOn(au_digen(dentry) != sigen); + } + if (inode && au_iigen(inode) != sigen) { + AuDebugOn(IS_ROOT(dentry)); + err = au_refresh_hinode(inode, dentry); + if (unlikely(err)) + goto out_dgrade; + AuDebugOn(au_iigen(inode) != sigen); + } + di_downgrade_lock(dentry, AuLock_IR); + + AuDebugOn(au_digen(dentry) != sigen); + AuDebugOn(inode && au_iigen(inode) != sigen); + err = -EINVAL; + do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE); + if (do_udba && inode) { + aufs_bindex_t bstart = au_ibstart(inode); + + if (bstart >= 0 + && au_test_higen(inode, au_h_iptr(inode, bstart))) + goto out; + } + + err = h_d_revalidate(dentry, inode, nd, do_udba); + if (unlikely(!err && do_udba && au_dbstart(dentry) < 0)) + /* both of real entry and whiteout found */ + err = -EIO; + goto out; + + out_dgrade: + di_downgrade_lock(dentry, AuLock_IR); + out: + au_store_oflag(nd); + aufs_read_unlock(dentry, AuLock_IR); + AuTraceErr(err); + valid = !err; + if (!valid) + AuDbg("%.*s invalid\n", AuDLNPair(dentry)); + return valid; +} + +static void aufs_d_release(struct dentry *dentry) +{ + struct au_dinfo *dinfo; + aufs_bindex_t bend, bindex; + + dinfo = dentry->d_fsdata; + if (!dinfo) + return; + + /* dentry may not be revalidated */ + bindex = dinfo->di_bstart; + if (bindex >= 0) { + struct au_hdentry *p; + + bend = dinfo->di_bend; + p = dinfo->di_hdentry + bindex; + while (bindex++ <= bend) { + if (p->hd_dentry) + au_hdput(p); + p++; + } + } + kfree(dinfo->di_hdentry); + au_rwsem_destroy(&dinfo->di_rwsem); + au_cache_free_dinfo(dinfo); + au_hin_di_reinit(dentry); +} + +struct dentry_operations aufs_dop = { + .d_revalidate = aufs_d_revalidate, + .d_release = aufs_d_release +}; diff --git a/fs/aufs/dentry.h b/fs/aufs/dentry.h new file mode 100644 index 0000000..8708db8 --- /dev/null +++ b/fs/aufs/dentry.h @@ -0,0 +1,213 @@ +/* + * Copyright (C) 2005-2009 Junjiro R. Okajima + * + * This program, aufs is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +/* + * lookup and dentry operations + */ + +#ifndef __AUFS_DENTRY_H__ +#define __AUFS_DENTRY_H__ + +#ifdef __KERNEL__ + +#include +#include +#include +#include "rwsem.h" + +/* make a single member structure for future use */ +/* todo: remove this structure */ +struct au_hdentry { + struct dentry *hd_dentry; +}; + +struct au_dinfo { + atomic_t di_generation; + + struct rw_semaphore di_rwsem; + aufs_bindex_t di_bstart, di_bend, di_bwh, di_bdiropq; + struct au_hdentry *di_hdentry; +}; + +/* ---------------------------------------------------------------------- */ + +/* dentry.c */ +extern struct dentry_operations aufs_dop; +struct au_branch; +struct dentry *au_lkup_one(struct qstr *name, struct dentry *h_parent, + struct au_branch *br, struct nameidata *nd); +struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent, + struct au_branch *br); +int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir, + struct dentry *h_parent, struct au_branch *br); + +int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type, + struct nameidata *nd); +int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex); +int au_refresh_hdentry(struct dentry *dentry, mode_t type); +int au_reval_dpath(struct dentry *dentry, unsigned int sigen); + +/* dinfo.c */ +int au_alloc_dinfo(struct dentry *dentry); +int au_di_realloc(struct au_dinfo *dinfo, int nbr); + +void di_read_lock(struct dentry *d, int flags, unsigned int lsc); +void di_read_unlock(struct dentry *d, int flags); +void di_downgrade_lock(struct dentry *d, int flags); +void di_write_lock(struct dentry *d, unsigned int lsc); +void di_write_unlock(struct dentry *d); +void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir); +void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir); +void di_write_unlock2(struct dentry *d1, struct dentry *d2); + +struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex); +aufs_bindex_t au_dbtail(struct dentry *dentry); +aufs_bindex_t au_dbtaildir(struct dentry *dentry); + +void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex, + struct dentry *h_dentry); +void au_update_digen(struct dentry *dentry); +void au_update_dbrange(struct dentry *dentry, int do_put_zero); +void au_update_dbstart(struct dentry *dentry); +void au_update_dbend(struct dentry *dentry); +int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry); + +/* ---------------------------------------------------------------------- */ + +static inline struct au_dinfo *au_di(struct dentry *dentry) +{ + return dentry->d_fsdata; +} + +/* ---------------------------------------------------------------------- */ + +/* lock subclass for dinfo */ +enum { + AuLsc_DI_CHILD, /* child first */ + AuLsc_DI_CHILD2, /* rename(2), link(2), and cpup at hinotify */ + AuLsc_DI_CHILD3, /* copyup dirs */ + AuLsc_DI_PARENT, + AuLsc_DI_PARENT2, + AuLsc_DI_PARENT3 +}; + +/* + * di_read_lock_child, di_write_lock_child, + * di_read_lock_child2, di_write_lock_child2, + * di_read_lock_child3, di_write_lock_child3, + * di_read_lock_parent, di_write_lock_parent, + * di_read_lock_parent2, di_write_lock_parent2, + * di_read_lock_parent3, di_write_lock_parent3, + */ +#define AuReadLockFunc(name, lsc) \ +static inline void di_read_lock_##name(struct dentry *d, int flags) \ +{ di_read_lock(d, flags, AuLsc_DI_##lsc); } + +#define AuWriteLockFunc(name, lsc) \ +static inline void di_write_lock_##name(struct dentry *d) \ +{ di_write_lock(d, AuLsc_DI_##lsc); } + +#define AuRWLockFuncs(name, lsc) \ + AuReadLockFunc(name, lsc) \ + AuWriteLockFunc(name, lsc) + +AuRWLockFuncs(child, CHILD); +AuRWLockFuncs(child2, CHILD2); +AuRWLockFuncs(child3, CHILD3); +AuRWLockFuncs(parent, PARENT); +AuRWLockFuncs(parent2, PARENT2); +AuRWLockFuncs(parent3, PARENT3); + +#undef AuReadLockFunc +#undef AuWriteLockFunc +#undef AuRWLockFuncs + +#define DiMustNoWaiters(d) AuRwMustNoWaiters(&au_di(d)->di_rwsem) + +/* ---------------------------------------------------------------------- */ + +/* todo: memory barrier? */ +static inline unsigned int au_digen(struct dentry *d) +{ + return atomic_read(&au_di(d)->di_generation); +} + +static inline void au_h_dentry_init(struct au_hdentry *hdentry) +{ + hdentry->hd_dentry = NULL; +} + +static inline void au_hdput(struct au_hdentry *hd) +{ + dput(hd->hd_dentry); +} + +static inline aufs_bindex_t au_dbstart(struct dentry *dentry) +{ + return au_di(dentry)->di_bstart; +} + +static inline aufs_bindex_t au_dbend(struct dentry *dentry) +{ + return au_di(dentry)->di_bend; +} + +static inline aufs_bindex_t au_dbwh(struct dentry *dentry) +{ + return au_di(dentry)->di_bwh; +} + +static inline aufs_bindex_t au_dbdiropq(struct dentry *dentry) +{ + return au_di(dentry)->di_bdiropq; +} + +/* todo: hard/soft set? */ +static inline void au_set_dbstart(struct dentry *dentry, aufs_bindex_t bindex) +{ + au_di(dentry)->di_bstart = bindex; +} + +static inline void au_set_dbend(struct dentry *dentry, aufs_bindex_t bindex) +{ + au_di(dentry)->di_bend = bindex; +} + +static inline void au_set_dbwh(struct dentry *dentry, aufs_bindex_t bindex) +{ + /* dbwh can be outside of bstart - bend range */ + au_di(dentry)->di_bwh = bindex; +} + +static inline void au_set_dbdiropq(struct dentry *dentry, aufs_bindex_t bindex) +{ + au_di(dentry)->di_bdiropq = bindex; +} + +/* ---------------------------------------------------------------------- */ + +#ifdef CONFIG_AUFS_HINOTIFY +static inline void au_digen_dec(struct dentry *d) +{ + atomic_dec(&au_di(d)->di_generation); +} + +static inline void au_hin_di_reinit(struct dentry *dentry) +{ + dentry->d_fsdata = NULL; +} +#else +static inline void au_hin_di_reinit(struct dentry *dentry __maybe_unused) +{ + /* empty */ +} +#endif /* CONFIG_AUFS_HINOTIFY */ + +#endif /* __KERNEL__ */ +#endif /* __AUFS_DENTRY_H__ */ diff --git a/fs/aufs/dinfo.c b/fs/aufs/dinfo.c new file mode 100644 index 0000000..b0645aa --- /dev/null +++ b/fs/aufs/dinfo.c @@ -0,0 +1,351 @@ +/* + * Copyright (C) 2005-2009 Junjiro R. Okajima + * + * This program, aufs is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +/* + * dentry private data + */ + +#include "aufs.h" + +int au_alloc_dinfo(struct dentry *dentry) +{ + struct au_dinfo *dinfo; + struct super_block *sb; + int nbr; + + dinfo = au_cache_alloc_dinfo(); + if (unlikely(!dinfo)) + goto out; + + sb = dentry->d_sb; + nbr = au_sbend(sb) + 1; + if (nbr <= 0) + nbr = 1; + dinfo->di_hdentry = kcalloc(nbr, sizeof(*dinfo->di_hdentry), GFP_NOFS); + if (unlikely(!dinfo->di_hdentry)) + goto out_dinfo; + + atomic_set(&dinfo->di_generation, au_sigen(sb)); + /* smp_mb(); */ /* atomic_set */ + init_rwsem(&dinfo->di_rwsem); + down_write_nested(&dinfo->di_rwsem, AuLsc_DI_CHILD); + dinfo->di_bstart = -1; + dinfo->di_bend = -1; + dinfo->di_bwh = -1; + dinfo->di_bdiropq = -1; + + dentry->d_fsdata = dinfo; + dentry->d_op = &aufs_dop; + return 0; /* success */ + + out_dinfo: + au_cache_free_dinfo(dinfo); + out: + return -ENOMEM; +} + +int au_di_realloc(struct au_dinfo *dinfo, int nbr) +{ + int err, sz; + struct au_hdentry *hdp; + + err = -ENOMEM; + sz = sizeof(*hdp) * (dinfo->di_bend + 1); + if (!sz) + sz = sizeof(*hdp); + hdp = au_kzrealloc(dinfo->di_hdentry, sz, sizeof(*hdp) * nbr, GFP_NOFS); + if (hdp) { + dinfo->di_hdentry = hdp; + err = 0; + } + + return err; +} + +/* ---------------------------------------------------------------------- */ + +static void do_ii_write_lock(struct inode *inode, unsigned int lsc) +{ + switch (lsc) { + case AuLsc_DI_CHILD: + ii_write_lock_child(inode); + break; + case AuLsc_DI_CHILD2: + ii_write_lock_child2(inode); + break; + case AuLsc_DI_CHILD3: + ii_write_lock_child3(inode); + break; + case AuLsc_DI_PARENT: + ii_write_lock_parent(inode); + break; + case AuLsc_DI_PARENT2: + ii_write_lock_parent2(inode); + break; + case AuLsc_DI_PARENT3: + ii_write_lock_parent3(inode); + break; + default: + BUG(); + } +} + +static void do_ii_read_lock(struct inode *inode, unsigned int lsc) +{ + switch (lsc) { + case AuLsc_DI_CHILD: + ii_read_lock_child(inode); + break; + case AuLsc_DI_CHILD2: + ii_read_lock_child2(inode); + break; + case AuLsc_DI_CHILD3: + ii_read_lock_child3(inode); + break; + case AuLsc_DI_PARENT: + ii_read_lock_parent(inode); + break; + case AuLsc_DI_PARENT2: + ii_read_lock_parent2(inode); + break; + case AuLsc_DI_PARENT3: + ii_read_lock_parent3(inode); + break; + default: + BUG(); + } +} + +void di_read_lock(struct dentry *d, int flags, unsigned int lsc) +{ + down_read_nested(&au_di(d)->di_rwsem, lsc); + if (d->d_inode) { + if (au_ftest_lock(flags, IW)) + do_ii_write_lock(d->d_inode, lsc); + else if (au_ftest_lock(flags, IR)) + do_ii_read_lock(d->d_inode, lsc); + } +} + +void di_read_unlock(struct dentry *d, int flags) +{ + if (d->d_inode) { + if (au_ftest_lock(flags, IW)) + ii_write_unlock(d->d_inode); + else if (au_ftest_lock(flags, IR)) + ii_read_unlock(d->d_inode); + } + up_read(&au_di(d)->di_rwsem); +} + +void di_downgrade_lock(struct dentry *d, int flags) +{ + downgrade_write(&au_di(d)->di_rwsem); + if (d->d_inode && au_ftest_lock(flags, IR)) + ii_downgrade_lock(d->d_inode); +} + +void di_write_lock(struct dentry *d, unsigned int lsc) +{ + down_write_nested(&au_di(d)->di_rwsem, lsc); + if (d->d_inode) + do_ii_write_lock(d->d_inode, lsc); +} + +void di_write_unlock(struct dentry *d) +{ + if (d->d_inode) + ii_write_unlock(d->d_inode); + up_write(&au_di(d)->di_rwsem); +} + +void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir) +{ + AuDebugOn(d1 == d2 + || d1->d_inode == d2->d_inode + || d1->d_sb != d2->d_sb); + + if (isdir && au_test_subdir(d1, d2)) { + di_write_lock_child(d1); + di_write_lock_child2(d2); + } else { + /* there should be no races */ + di_write_lock_child(d2); + di_write_lock_child2(d1); + } +} + +void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir) +{ + AuDebugOn(d1 == d2 + || d1->d_inode == d2->d_inode + || d1->d_sb != d2->d_sb); + + if (isdir && au_test_subdir(d1, d2)) { + di_write_lock_parent(d1); + di_write_lock_parent2(d2); + } else { + /* there should be no races */ + di_write_lock_parent(d2); + di_write_lock_parent2(d1); + } +} + +void di_write_unlock2(struct dentry *d1, struct dentry *d2) +{ + di_write_unlock(d1); + if (d1->d_inode == d2->d_inode) + up_write(&au_di(d2)->di_rwsem); + else + di_write_unlock(d2); +} + +/* ---------------------------------------------------------------------- */ + +struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex) +{ + struct dentry *d; + + if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry)) + return NULL; + AuDebugOn(bindex < 0); + d = au_di(dentry)->di_hdentry[0 + bindex].hd_dentry; + AuDebugOn(d && (atomic_read(&d->d_count) <= 0)); + return d; +} + +aufs_bindex_t au_dbtail(struct dentry *dentry) +{ + aufs_bindex_t bend, bwh; + + bend = au_dbend(dentry); + if (0 <= bend) { + bwh = au_dbwh(dentry); + if (!bwh) + return bwh; + if (0 < bwh && bwh < bend) + return bwh - 1; + } + return bend; +} + +aufs_bindex_t au_dbtaildir(struct dentry *dentry) +{ + aufs_bindex_t bend, bopq; + + bend = au_dbtail(dentry); + if (0 <= bend) { + bopq = au_dbdiropq(dentry); + if (0 <= bopq && bopq < bend) + bend = bopq; + } + return bend; +} + +/* ---------------------------------------------------------------------- */ + +void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex, + struct dentry *h_dentry) +{ + struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex; + + if (hd->hd_dentry) + au_hdput(hd); + hd->hd_dentry = h_dentry; +} + +void au_update_digen(struct dentry *dentry) +{ + atomic_set(&au_di(dentry)->di_generation, au_sigen(dentry->d_sb)); + /* smp_mb(); */ /* atomic_set */ +} + +void au_update_dbrange(struct dentry *dentry, int do_put_zero) +{ + struct au_dinfo *dinfo; + struct dentry *h_d; + + dinfo = au_di(dentry); + if (!dinfo || dinfo->di_bstart < 0) + return; + + if (do_put_zero) { + aufs_bindex_t bindex, bend; + + bend = dinfo->di_bend; + for (bindex = dinfo->di_bstart; bindex <= bend; bindex++) { + h_d = dinfo->di_hdentry[0 + bindex].hd_dentry; + if (h_d && !h_d->d_inode) + au_set_h_dptr(dentry, bindex, NULL); + } + } + + dinfo->di_bstart = -1; + while (++dinfo->di_bstart <= dinfo->di_bend) + if (dinfo->di_hdentry[0 + dinfo->di_bstart].hd_dentry) + break; + if (dinfo->di_bstart > dinfo->di_bend) { + dinfo->di_bstart = -1; + dinfo->di_bend = -1; + return; + } + + dinfo->di_bend++; + while (0 <= --dinfo->di_bend) + if (dinfo->di_hdentry[0 + dinfo->di_bend].hd_dentry) + break; + AuDebugOn(dinfo->di_bstart > dinfo->di_bend || dinfo->di_bend < 0); +} + +void au_update_dbstart(struct dentry *dentry) +{ + aufs_bindex_t bindex, bend; + struct dentry *h_dentry; + + bend = au_dbend(dentry); + for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) { + h_dentry = au_h_dptr(dentry, bindex); + if (!h_dentry) + continue; + if (h_dentry->d_inode) { + au_set_dbstart(dentry, bindex); + return; + } + au_set_h_dptr(dentry, bindex, NULL); + } +} + +void au_update_dbend(struct dentry *dentry) +{ + aufs_bindex_t bindex, bstart; + struct dentry *h_dentry; + + bstart = au_dbstart(dentry); + for (bindex = au_dbend(dentry); bindex <= bstart; bindex--) { + h_dentry = au_h_dptr(dentry, bindex); + if (!h_dentry) + continue; + if (h_dentry->d_inode) { + au_set_dbend(dentry, bindex); + return; + } + au_set_h_dptr(dentry, bindex, NULL); + } +} + +int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry) +{ + aufs_bindex_t bindex, bend; + + bend = au_dbend(dentry); + for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) + if (au_h_dptr(dentry, bindex) == h_dentry) + return bindex; + return -1; +} -- 1.6.1.284.g5dc13 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/