From: Lai Siyao <lai.siyao@xxxxxxxxx> Lustre client dentry validation is protected by LDLM lock, so any time a dentry is found, it's valid and no need to revalidate from MDS, and even it does, there is race that it may be invalidated after revalidation is finished. Signed-off-by: Lai Siyao <lai.siyao@xxxxxxxxx> Reviewed-on: http://review.whamcloud.com/7475 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3544 Reviewed-by: Peng Tao <bergwolf@xxxxxxxxx> Reviewed-by: Bob Glossman <bob.glossman@xxxxxxxxx> Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx> Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx> Signed-off-by: Oleg Drokin <oleg.drokin@xxxxxxxxx> --- .../lustre/lustre/include/lustre/lustre_idl.h | 2 +- drivers/staging/lustre/lustre/llite/dcache.c | 290 ++------------------- drivers/staging/lustre/lustre/llite/file.c | 8 +- .../staging/lustre/lustre/llite/llite_internal.h | 4 +- drivers/staging/lustre/lustre/lmv/lmv_intent.c | 1 - drivers/staging/lustre/lustre/lmv/lmv_obd.c | 1 - drivers/staging/lustre/lustre/mdc/mdc_locks.c | 52 ++-- 7 files changed, 45 insertions(+), 313 deletions(-) diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h index a55eebf..5f5b0ba 100644 --- a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h +++ b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h @@ -2112,7 +2112,7 @@ extern void lustre_swab_generic_32s (__u32 *val); #define DISP_LOOKUP_POS 0x00000008 #define DISP_OPEN_CREATE 0x00000010 #define DISP_OPEN_OPEN 0x00000020 -#define DISP_ENQ_COMPLETE 0x00400000 +#define DISP_ENQ_COMPLETE 0x00400000 /* obsolete and unused */ #define DISP_ENQ_OPEN_REF 0x00800000 #define DISP_ENQ_CREATE_REF 0x01000000 #define DISP_OPEN_LOCK 0x02000000 diff --git a/drivers/staging/lustre/lustre/llite/dcache.c b/drivers/staging/lustre/lustre/llite/dcache.c index 3907c87..f971a54 100644 --- a/drivers/staging/lustre/lustre/llite/dcache.c +++ b/drivers/staging/lustre/lustre/llite/dcache.c @@ -241,9 +241,6 @@ void ll_intent_release(struct lookup_intent *it) ptlrpc_req_finished(it->d.lustre.it_data); /* ll_file_open */ if (it_disposition(it, DISP_ENQ_CREATE_REF)) /* create rec */ ptlrpc_req_finished(it->d.lustre.it_data); - if (it_disposition(it, DISP_ENQ_COMPLETE)) /* saved req from revalidate - * to lookup */ - ptlrpc_req_finished(it->d.lustre.it_data); it->d.lustre.it_disposition = 0; it->d.lustre.it_data = NULL; @@ -328,262 +325,32 @@ void ll_frob_intent(struct lookup_intent **itp, struct lookup_intent *deft) } -int ll_revalidate_it(struct dentry *de, int lookup_flags, - struct lookup_intent *it) +static int ll_revalidate_dentry(struct dentry *dentry, + unsigned int lookup_flags) { - struct md_op_data *op_data; - struct ptlrpc_request *req = NULL; - struct lookup_intent lookup_it = { .it_op = IT_LOOKUP }; - struct obd_export *exp; - struct inode *parent = de->d_parent->d_inode; - int rc; - - CDEBUG(D_VFSTRACE, "VFS Op:name=%s,intent=%s\n", de->d_name.name, - LL_IT2STR(it)); - - LASSERT(de != de->d_sb->s_root); - - if (de->d_inode == NULL) { - __u64 ibits; - - /* We can only use negative dentries if this is stat or lookup, - for opens and stuff we do need to query server. */ - /* If there is IT_CREAT in intent op set, then we must throw - away this negative dentry and actually do the request to - kernel to create whatever needs to be created (if possible)*/ - if (it && (it->it_op & IT_CREAT)) - return 0; + struct inode *dir = dentry->d_parent->d_inode; - if (d_lustre_invalid(de)) - return 0; - - ibits = MDS_INODELOCK_UPDATE; - rc = ll_have_md_lock(parent, &ibits, LCK_MINMODE); - GOTO(out_sa, rc); - } - - /* Never execute intents for mount points. - * Attributes will be fixed up in ll_inode_revalidate_it */ - if (d_mountpoint(de)) - GOTO(out_sa, rc = 1); - - exp = ll_i2mdexp(de->d_inode); - - OBD_FAIL_TIMEOUT(OBD_FAIL_MDC_REVALIDATE_PAUSE, 5); - ll_frob_intent(&it, &lookup_it); - LASSERT(it); + /* + * if open&create is set, talk to MDS to make sure file is created if + * necessary, because we can't do this in ->open() later since that's + * called on an inode. return 0 here to let lookup to handle this. + */ + if ((lookup_flags & (LOOKUP_OPEN | LOOKUP_CREATE)) == + (LOOKUP_OPEN | LOOKUP_CREATE)) + return 0; - if (it->it_op == IT_LOOKUP && !d_lustre_invalid(de)) + if (lookup_flags & (LOOKUP_PARENT | LOOKUP_OPEN | LOOKUP_CREATE)) return 1; - if (it->it_op == IT_OPEN) { - struct inode *inode = de->d_inode; - struct ll_inode_info *lli = ll_i2info(inode); - struct obd_client_handle **och_p; - __u64 ibits; - - /* - * We used to check for MDS_INODELOCK_OPEN here, but in fact - * just having LOOKUP lock is enough to justify inode is the - * same. And if inode is the same and we have suitable - * openhandle, then there is no point in doing another OPEN RPC - * just to throw away newly received openhandle. There are no - * security implications too, if file owner or access mode is - * change, LOOKUP lock is revoked. - */ - - - if (it->it_flags & FMODE_WRITE) - och_p = &lli->lli_mds_write_och; - else if (it->it_flags & FMODE_EXEC) - och_p = &lli->lli_mds_exec_och; - else - och_p = &lli->lli_mds_read_och; - - /* Check for the proper lock. */ - ibits = MDS_INODELOCK_LOOKUP; - if (!ll_have_md_lock(inode, &ibits, LCK_MINMODE)) - goto do_lock; - mutex_lock(&lli->lli_och_mutex); - if (*och_p) { /* Everything is open already, do nothing */ - /* Originally it was idea to do not let them steal our - * open handle from under us by (*och_usecount)++ here. - * But in case we have the handle, but we cannot use it - * due to later checks (e.g. O_CREAT|O_EXCL flags set), - * nobody would decrement counter increased here. So we - * just hope the lock won't be invalidated in between. - * But if it would be, we'll reopen the open request to - * MDS later during file open path. - */ - mutex_unlock(&lli->lli_och_mutex); - return 1; - } - mutex_unlock(&lli->lli_och_mutex); - } - - if (it->it_op == IT_GETATTR) { - rc = ll_statahead_enter(parent, &de, 0); - if (rc == 1) - goto mark; - else if (rc != -EAGAIN && rc != 0) - GOTO(out, rc = 0); - } - -do_lock: - op_data = ll_prep_md_op_data(NULL, parent, de->d_inode, - de->d_name.name, de->d_name.len, - 0, LUSTRE_OPC_ANY, NULL); - if (IS_ERR(op_data)) - return PTR_ERR(op_data); - - if (!IS_POSIXACL(parent) || !exp_connect_umask(exp)) - it->it_create_mode &= ~current_umask(); - it->it_create_mode |= M_CHECK_STALE; - rc = md_intent_lock(exp, op_data, NULL, 0, it, - lookup_flags, - &req, ll_md_blocking_ast, 0); - it->it_create_mode &= ~M_CHECK_STALE; - ll_finish_md_op_data(op_data); - - /* If req is NULL, then md_intent_lock only tried to do a lock match; - * if all was well, it will return 1 if it found locks, 0 otherwise. */ - if (req == NULL && rc >= 0) { - if (!rc) - goto do_lookup; - GOTO(out, rc); - } - - if (rc < 0) { - if (rc != -ESTALE) { - CDEBUG(D_INFO, "ll_intent_lock: rc %d : it->it_status " - "%d\n", rc, it->d.lustre.it_status); - } - GOTO(out, rc = 0); - } - -revalidate_finish: - rc = ll_revalidate_it_finish(req, it, de); - if (rc != 0) { - if (rc != -ESTALE && rc != -ENOENT) - ll_intent_release(it); - GOTO(out, rc = 0); - } - - if ((it->it_op & IT_OPEN) && de->d_inode && - !S_ISREG(de->d_inode->i_mode) && - !S_ISDIR(de->d_inode->i_mode)) { - ll_release_openhandle(de, it); - } - rc = 1; - -out: - /* We do not free request as it may be reused during following lookup - * (see comment in mdc/mdc_locks.c::mdc_intent_lock()), request will - * be freed in ll_lookup_it or in ll_intent_release. But if - * request was not completed, we need to free it. (bug 5154, 9903) */ - if (req != NULL && !it_disposition(it, DISP_ENQ_COMPLETE)) - ptlrpc_req_finished(req); - if (rc == 0) { - /* mdt may grant layout lock for the newly created file, so - * release the lock to avoid leaking */ - ll_intent_drop_lock(it); - ll_invalidate_aliases(de->d_inode); - } else { - __u64 bits = 0; - __u64 matched_bits = 0; - - CDEBUG(D_DENTRY, "revalidated dentry %.*s (%p) parent %p " - "inode %p refc %d\n", de->d_name.len, - de->d_name.name, de, de->d_parent, de->d_inode, - d_count(de)); - - ll_set_lock_data(exp, de->d_inode, it, &bits); - - /* Note: We have to match both LOOKUP and PERM lock - * here to make sure the dentry is valid and no one - * changing the permission. - * But if the client connects < 2.4 server, which will - * only grant LOOKUP lock, so we can only Match LOOKUP - * lock for old server */ - if (exp_connect_flags(ll_i2mdexp(de->d_inode)) && - OBD_CONNECT_LVB_TYPE) - matched_bits = - MDS_INODELOCK_LOOKUP | MDS_INODELOCK_PERM; - else - matched_bits = MDS_INODELOCK_LOOKUP; - - if (((bits & matched_bits) == matched_bits) && - d_lustre_invalid(de)) - d_lustre_revalidate(de); - ll_lookup_finish_locks(it, de); - } - -mark: - if (it != NULL && it->it_op == IT_GETATTR && rc > 0) - ll_statahead_mark(parent, de); - return rc; + if (d_need_statahead(dir, dentry) <= 0) + return 1; - /* - * This part is here to combat evil-evil race in real_lookup on 2.6 - * kernels. The race details are: We enter do_lookup() looking for some - * name, there is nothing in dcache for this name yet and d_lookup() - * returns NULL. We proceed to real_lookup(), and while we do this, - * another process does open on the same file we looking up (most simple - * reproducer), open succeeds and the dentry is added. Now back to - * us. In real_lookup() we do d_lookup() again and suddenly find the - * dentry, so we call d_revalidate on it, but there is no lock, so - * without this code we would return 0, but unpatched real_lookup just - * returns -ENOENT in such a case instead of retrying the lookup. Once - * this is dealt with in real_lookup(), all of this ugly mess can go and - * we can just check locks in ->d_revalidate without doing any RPCs - * ever. - */ -do_lookup: - if (it != &lookup_it) { - /* MDS_INODELOCK_UPDATE needed for IT_GETATTR case. */ - if (it->it_op == IT_GETATTR) - lookup_it.it_op = IT_GETATTR; - ll_lookup_finish_locks(it, de); - it = &lookup_it; - } + if (lookup_flags & LOOKUP_RCU) + return -ECHILD; - /* Do real lookup here. */ - op_data = ll_prep_md_op_data(NULL, parent, NULL, de->d_name.name, - de->d_name.len, 0, (it->it_op & IT_CREAT ? - LUSTRE_OPC_CREATE : - LUSTRE_OPC_ANY), NULL); - if (IS_ERR(op_data)) - return PTR_ERR(op_data); - - rc = md_intent_lock(exp, op_data, NULL, 0, it, 0, &req, - ll_md_blocking_ast, 0); - if (rc >= 0) { - struct mdt_body *mdt_body; - struct lu_fid fid = {.f_seq = 0, .f_oid = 0, .f_ver = 0}; - mdt_body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY); - - if (de->d_inode) - fid = *ll_inode2fid(de->d_inode); - - /* see if we got same inode, if not - return error */ - if (lu_fid_eq(&fid, &mdt_body->fid1)) { - ll_finish_md_op_data(op_data); - op_data = NULL; - goto revalidate_finish; - } - ll_intent_release(it); - } - ll_finish_md_op_data(op_data); - GOTO(out, rc = 0); - -out_sa: - /* - * For rc == 1 case, should not return directly to prevent losing - * statahead windows; for rc == 0 case, the "lookup" will be done later. - */ - if (it != NULL && it->it_op == IT_GETATTR && rc == 1) - ll_statahead_enter(parent, &de, 1); - goto mark; + do_statahead_enter(dir, &dentry, dentry->d_inode == NULL); + ll_statahead_mark(dir, dentry); + return 1; } /* @@ -591,24 +358,13 @@ out_sa: */ int ll_revalidate_nd(struct dentry *dentry, unsigned int flags) { - struct inode *parent = dentry->d_parent->d_inode; - int unplug = 0; + int rc; - CDEBUG(D_VFSTRACE, "VFS Op:name=%s,flags=%u\n", + CDEBUG(D_VFSTRACE, "VFS Op:name=%s, flags=%u\n", dentry->d_name.name, flags); - if (!(flags & (LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE)) && - ll_need_statahead(parent, dentry) > 0) { - if (flags & LOOKUP_RCU) - return -ECHILD; - - if (dentry->d_inode == NULL) - unplug = 1; - do_statahead_enter(parent, &dentry, unplug); - ll_statahead_mark(parent, dentry); - } - - return 1; + rc = ll_revalidate_dentry(dentry, flags); + return rc; } diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c index 7ceec74..70b48ab 100644 --- a/drivers/staging/lustre/lustre/llite/file.c +++ b/drivers/staging/lustre/lustre/llite/file.c @@ -446,8 +446,7 @@ static int ll_intent_file_open(struct file *file, void *lmm, itp, NULL); out: - ptlrpc_req_finished(itp->d.lustre.it_data); - it_clear_disposition(itp, DISP_ENQ_COMPLETE); + ptlrpc_req_finished(req); ll_intent_drop_lock(itp); return rc; @@ -815,10 +814,7 @@ struct obd_client_handle *ll_lease_open(struct inode *inode, struct file *file, * doesn't deal with openhandle, so normal openhandle will be leaked. */ LDLM_FL_NO_LRU | LDLM_FL_EXCL); ll_finish_md_op_data(op_data); - if (req != NULL) { - ptlrpc_req_finished(req); - it_clear_disposition(&it, DISP_ENQ_COMPLETE); - } + ptlrpc_req_finished(req); if (rc < 0) GOTO(out_release_it, rc); diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h index 47c5142..f67c508 100644 --- a/drivers/staging/lustre/lustre/llite/llite_internal.h +++ b/drivers/staging/lustre/lustre/llite/llite_internal.h @@ -1309,7 +1309,7 @@ ll_statahead_mark(struct inode *dir, struct dentry *dentry) } static inline int -ll_need_statahead(struct inode *dir, struct dentry *dentryp) +d_need_statahead(struct inode *dir, struct dentry *dentryp) { struct ll_inode_info *lli; struct ll_dentry_data *ldd; @@ -1354,7 +1354,7 @@ ll_statahead_enter(struct inode *dir, struct dentry **dentryp, int only_unplug) { int ret; - ret = ll_need_statahead(dir, *dentryp); + ret = d_need_statahead(dir, *dentryp); if (ret <= 0) return ret; diff --git a/drivers/staging/lustre/lustre/lmv/lmv_intent.c b/drivers/staging/lustre/lustre/lmv/lmv_intent.c index 56dedce..9ba5a0a 100644 --- a/drivers/staging/lustre/lustre/lmv/lmv_intent.c +++ b/drivers/staging/lustre/lustre/lmv/lmv_intent.c @@ -119,7 +119,6 @@ static int lmv_intent_remote(struct obd_export *exp, void *lmm, CDEBUG(D_INODE, "REMOTE_INTENT with fid="DFID" -> mds #%d\n", PFID(&body->fid1), tgt->ltd_idx); - it->d.lustre.it_disposition &= ~DISP_ENQ_COMPLETE; rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it, flags, &req, cb_blocking, extra_lock_flags); if (rc) diff --git a/drivers/staging/lustre/lustre/lmv/lmv_obd.c b/drivers/staging/lustre/lustre/lmv/lmv_obd.c index 40fbd44..3ba0a0a 100644 --- a/drivers/staging/lustre/lustre/lmv/lmv_obd.c +++ b/drivers/staging/lustre/lustre/lmv/lmv_obd.c @@ -1744,7 +1744,6 @@ lmv_enqueue_remote(struct obd_export *exp, struct ldlm_enqueue_info *einfo, it->d.lustre.it_data = NULL; fid1 = body->fid1; - it->d.lustre.it_disposition &= ~DISP_ENQ_COMPLETE; ptlrpc_req_finished(req); tgt = lmv_find_target(lmv, &fid1); diff --git a/drivers/staging/lustre/lustre/mdc/mdc_locks.c b/drivers/staging/lustre/lustre/mdc/mdc_locks.c index 20706e7..81adc2b 100644 --- a/drivers/staging/lustre/lustre/mdc/mdc_locks.c +++ b/drivers/staging/lustre/lustre/mdc/mdc_locks.c @@ -968,7 +968,6 @@ static int mdc_finish_intent_lock(struct obd_export *exp, if (fid_is_sane(&op_data->op_fid2) && it->it_create_mode & M_CHECK_STALE && it->it_op != IT_GETATTR) { - it_set_disposition(it, DISP_ENQ_COMPLETE); /* Also: did we find the same inode? */ /* sever can return one of two fids: @@ -1139,6 +1138,12 @@ int mdc_intent_lock(struct obd_export *exp, struct md_op_data *op_data, ldlm_blocking_callback cb_blocking, __u64 extra_lock_flags) { + struct ldlm_enqueue_info einfo = { + .ei_type = LDLM_IBITS, + .ei_mode = it_to_lock_mode(it), + .ei_cb_bl = cb_blocking, + .ei_cb_cp = ldlm_completion_ast, + }; struct lustre_handle lockh; int rc = 0; @@ -1164,42 +1169,19 @@ int mdc_intent_lock(struct obd_export *exp, struct md_op_data *op_data, return rc; } - /* lookup_it may be called only after revalidate_it has run, because - * revalidate_it cannot return errors, only zero. Returning zero causes - * this call to lookup, which *can* return an error. - * - * We only want to execute the request associated with the intent one - * time, however, so don't send the request again. Instead, skip past - * this and use the request from revalidate. In this case, revalidate - * never dropped its reference, so the refcounts are all OK */ - if (!it_disposition(it, DISP_ENQ_COMPLETE)) { - struct ldlm_enqueue_info einfo = { - .ei_type = LDLM_IBITS, - .ei_mode = it_to_lock_mode(it), - .ei_cb_bl = cb_blocking, - .ei_cb_cp = ldlm_completion_ast, - }; - - /* For case if upper layer did not alloc fid, do it now. */ - if (!fid_is_sane(&op_data->op_fid2) && it->it_op & IT_CREAT) { - rc = mdc_fid_alloc(exp, &op_data->op_fid2, op_data); - if (rc < 0) { - CERROR("Can't alloc new fid, rc %d\n", rc); - return rc; - } - } - rc = mdc_enqueue(exp, &einfo, it, op_data, &lockh, - lmm, lmmsize, NULL, extra_lock_flags); - if (rc < 0) + /* For case if upper layer did not alloc fid, do it now. */ + if (!fid_is_sane(&op_data->op_fid2) && it->it_op & IT_CREAT) { + rc = mdc_fid_alloc(exp, &op_data->op_fid2, op_data); + if (rc < 0) { + CERROR("Can't alloc new fid, rc %d\n", rc); return rc; - } else if (!fid_is_sane(&op_data->op_fid2) || - !(it->it_create_mode & M_CHECK_STALE)) { - /* DISP_ENQ_COMPLETE set means there is extra reference on - * request referenced from this intent, saved for subsequent - * lookup. This path is executed when we proceed to this - * lookup, so we clear DISP_ENQ_COMPLETE */ - it_clear_disposition(it, DISP_ENQ_COMPLETE); + } } + rc = mdc_enqueue(exp, &einfo, it, op_data, &lockh, lmm, lmmsize, NULL, + extra_lock_flags); + if (rc < 0) + return rc; + *reqp = it->d.lustre.it_data; rc = mdc_finish_intent_lock(exp, *reqp, op_data, it, &lockh); return rc; -- 1.8.5.3 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
