From b80c3cb628f0ebc241b02e38dd028969fb8026a2 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 9 Apr 2010 19:07:07 -0400 Subject: NFS: Ensure that writeback_single_inode() calls write_inode() when syncing Since writeback_single_inode() checks the inode->i_state flags _before_ it flushes out the data, we need to ensure that the I_DIRTY_DATASYNC flag is already set. Otherwise we risk not seeing a call to write_inode(), which again means that we break fsync() et al... Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 53ff70e2399..7f40ea30554 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -421,6 +421,7 @@ static void nfs_mark_request_dirty(struct nfs_page *req) { __set_page_dirty_nobuffers(req->wb_page); + __mark_inode_dirty(req->wb_page->mapping->host, I_DIRTY_DATASYNC); } #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) @@ -660,6 +661,7 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, req = nfs_setup_write_request(ctx, page, offset, count); if (IS_ERR(req)) return PTR_ERR(req); + nfs_mark_request_dirty(req); /* Update file length */ nfs_grow_file(page, offset, count); nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); @@ -739,8 +741,6 @@ int nfs_updatepage(struct file *file, struct page *page, status = nfs_writepage_setup(ctx, page, offset, count); if (status < 0) nfs_set_pageerror(page); - else - __set_page_dirty_nobuffers(page); dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", status, (long long)i_size_read(inode)); -- cgit v1.2.3-70-g09d2 From a6305ddb080fb483ca41ca56cacb6f96089f0c8e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 9 Apr 2010 19:07:08 -0400 Subject: NFS: Fix a race with the new commit code This patch fixes a race which occurs due to the fact that we release the PG_writeback flag while still holding the nfs_page locked. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 7f40ea30554..40297c4f1ee 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -201,6 +201,7 @@ static int nfs_set_page_writeback(struct page *page) struct inode *inode = page->mapping->host; struct nfs_server *nfss = NFS_SERVER(inode); + page_cache_get(page); if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH) { set_bdi_congested(&nfss->backing_dev_info, @@ -216,6 +217,7 @@ static void nfs_end_page_writeback(struct page *page) struct nfs_server *nfss = NFS_SERVER(inode); end_page_writeback(page); + page_cache_release(page); if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); } @@ -665,6 +667,7 @@ static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, /* Update file length */ nfs_grow_file(page, offset, count); nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); + nfs_mark_request_dirty(req); nfs_clear_page_tag_locked(req); return 0; } @@ -749,13 +752,12 @@ int nfs_updatepage(struct file *file, struct page *page, static void nfs_writepage_release(struct nfs_page *req) { + struct page *page = req->wb_page; - if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) { - nfs_end_page_writeback(req->wb_page); + if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) nfs_inode_remove_request(req); - } else - nfs_end_page_writeback(req->wb_page); nfs_clear_page_tag_locked(req); + nfs_end_page_writeback(page); } static int flush_task_priority(int how) @@ -847,9 +849,11 @@ static int nfs_write_rpcsetup(struct nfs_page *req, */ static void nfs_redirty_request(struct nfs_page *req) { + struct page *page = req->wb_page; + nfs_mark_request_dirty(req); - nfs_end_page_writeback(req->wb_page); nfs_clear_page_tag_locked(req); + nfs_end_page_writeback(page); } /* @@ -1084,16 +1088,15 @@ static void nfs_writeback_release_full(void *calldata) if (nfs_write_need_commit(data)) { memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); nfs_mark_request_commit(req); - nfs_end_page_writeback(page); dprintk(" marked for commit\n"); goto next; } dprintk(" OK\n"); remove_request: - nfs_end_page_writeback(page); nfs_inode_remove_request(req); next: nfs_clear_page_tag_locked(req); + nfs_end_page_writeback(page); } nfs_writedata_release(calldata); } -- cgit v1.2.3-70-g09d2 From 2c61be0a9478258f77b66208a0c4b1f5f8161c3c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 9 Apr 2010 19:54:50 -0400 Subject: NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible We always want to ensure that WRITE and COMMIT completes, whether or not the user presses ^C. Do this by making the call asynchronous, and allowing the user to do an interruptible wait for rpc_task completion. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 40297c4f1ee..de38d63aa92 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -781,7 +781,6 @@ static int nfs_write_rpcsetup(struct nfs_page *req, int how) { struct inode *inode = req->wb_context->path.dentry->d_inode; - int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC; int priority = flush_task_priority(how); struct rpc_task *task; struct rpc_message msg = { @@ -796,9 +795,10 @@ static int nfs_write_rpcsetup(struct nfs_page *req, .callback_ops = call_ops, .callback_data = data, .workqueue = nfsiod_workqueue, - .flags = flags, + .flags = RPC_TASK_ASYNC, .priority = priority, }; + int ret = 0; /* Set up the RPC argument and reply structs * NB: take care not to mess about with data->commit et al. */ @@ -837,10 +837,18 @@ static int nfs_write_rpcsetup(struct nfs_page *req, (unsigned long long)data->args.offset); task = rpc_run_task(&task_setup_data); - if (IS_ERR(task)) - return PTR_ERR(task); + if (IS_ERR(task)) { + ret = PTR_ERR(task); + goto out; + } + if (how & FLUSH_SYNC) { + ret = rpc_wait_for_completion_task(task); + if (ret == 0) + ret = task->tk_status; + } rpc_put_task(task); - return 0; +out: + return ret; } /* If a nfs_flush_* function fails, it should remove reqs from @head and @@ -1210,7 +1218,6 @@ static int nfs_commit_rpcsetup(struct list_head *head, { struct nfs_page *first = nfs_list_entry(head->next); struct inode *inode = first->wb_context->path.dentry->d_inode; - int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC; int priority = flush_task_priority(how); struct rpc_task *task; struct rpc_message msg = { @@ -1225,7 +1232,7 @@ static int nfs_commit_rpcsetup(struct list_head *head, .callback_ops = &nfs_commit_ops, .callback_data = data, .workqueue = nfsiod_workqueue, - .flags = flags, + .flags = RPC_TASK_ASYNC, .priority = priority, }; @@ -1255,6 +1262,8 @@ static int nfs_commit_rpcsetup(struct list_head *head, task = rpc_run_task(&task_setup_data); if (IS_ERR(task)) return PTR_ERR(task); + if (how & FLUSH_SYNC) + rpc_wait_for_completion_task(task); rpc_put_task(task); return 0; } -- cgit v1.2.3-70-g09d2 From 71d0a6112a363e703e383ae5b12c492485c39701 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 22 Apr 2010 15:35:57 -0400 Subject: NFS: Fix an unstable write data integrity race Commit 2c61be0a9478258f77b66208a0c4b1f5f8161c3c (NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible) exposed a race on file close. In order to ensure correct close-to-open behaviour, we want to wait for all outstanding background commit operations to complete. This patch adds an inode flag that indicates if a commit operation is under way, and provides a mechanism to allow ->write_inode() to wait for its completion if this is a data integrity flush. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 36 ++++++++++++++++++++++++++++++++---- include/linux/nfs_fs.h | 1 + 2 files changed, 33 insertions(+), 4 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index de38d63aa92..ccde2aeb3fe 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1201,6 +1201,25 @@ int nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data) #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) +static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) +{ + if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) + return 1; + if (may_wait && !out_of_line_wait_on_bit_lock(&nfsi->flags, + NFS_INO_COMMIT, nfs_wait_bit_killable, + TASK_KILLABLE)) + return 1; + return 0; +} + +static void nfs_commit_clear_lock(struct nfs_inode *nfsi) +{ + clear_bit(NFS_INO_COMMIT, &nfsi->flags); + smp_mb__after_clear_bit(); + wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); +} + + static void nfs_commitdata_release(void *data) { struct nfs_write_data *wdata = data; @@ -1262,8 +1281,6 @@ static int nfs_commit_rpcsetup(struct list_head *head, task = rpc_run_task(&task_setup_data); if (IS_ERR(task)) return PTR_ERR(task); - if (how & FLUSH_SYNC) - rpc_wait_for_completion_task(task); rpc_put_task(task); return 0; } @@ -1294,6 +1311,7 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how) BDI_RECLAIMABLE); nfs_clear_page_tag_locked(req); } + nfs_commit_clear_lock(NFS_I(inode)); return -ENOMEM; } @@ -1349,6 +1367,7 @@ static void nfs_commit_release(void *calldata) next: nfs_clear_page_tag_locked(req); } + nfs_commit_clear_lock(NFS_I(data->inode)); nfs_commitdata_release(calldata); } @@ -1363,8 +1382,11 @@ static const struct rpc_call_ops nfs_commit_ops = { static int nfs_commit_inode(struct inode *inode, int how) { LIST_HEAD(head); - int res; + int may_wait = how & FLUSH_SYNC; + int res = 0; + if (!nfs_commit_set_lock(NFS_I(inode), may_wait)) + goto out; spin_lock(&inode->i_lock); res = nfs_scan_commit(inode, &head, 0, 0); spin_unlock(&inode->i_lock); @@ -1372,7 +1394,13 @@ static int nfs_commit_inode(struct inode *inode, int how) int error = nfs_commit_list(inode, &head, how); if (error < 0) return error; - } + if (may_wait) + wait_on_bit(&NFS_I(inode)->flags, NFS_INO_COMMIT, + nfs_wait_bit_killable, + TASK_KILLABLE); + } else + nfs_commit_clear_lock(NFS_I(inode)); +out: return res; } diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 1a0b85aa151..07ce4609fe5 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -209,6 +209,7 @@ struct nfs_inode { #define NFS_INO_FLUSHING (4) /* inode is flushing out data */ #define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */ #define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */ +#define NFS_INO_COMMIT (7) /* inode is committing unstable writes */ static inline struct nfs_inode *NFS_I(const struct inode *inode) { -- cgit v1.2.3-70-g09d2 From ba8b06e67ed7a560b0e7c80091bcadda4f4727a5 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 27 Apr 2010 18:33:54 -0400 Subject: NFS: Ensure that nfs_wb_page() waits for Pg_writeback to clear Neil Brown reports that he is seeing the BUG_ON(ret == 0) trigger in nfs_page_async_flush. According to the trace in https://bugzilla.novell.com/show_bug.cgi?id=599628 the problem appears to be due to nfs_wb_page() not waiting for the PG_writeback flag to clear. There is a ditto problem in nfs_wb_page_cancel() Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index ccde2aeb3fe..3aea3ca98ab 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1472,6 +1472,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page) BUG_ON(!PageLocked(page)); for (;;) { + wait_on_page_writeback(page); req = nfs_page_find_request(page); if (req == NULL) break; @@ -1506,30 +1507,18 @@ int nfs_wb_page(struct inode *inode, struct page *page) .range_start = range_start, .range_end = range_end, }; - struct nfs_page *req; - int need_commit; int ret; while(PagePrivate(page)) { + wait_on_page_writeback(page); if (clear_page_dirty_for_io(page)) { ret = nfs_writepage_locked(page, &wbc); if (ret < 0) goto out_error; } - req = nfs_find_and_lock_request(page); - if (!req) - break; - if (IS_ERR(req)) { - ret = PTR_ERR(req); + ret = sync_inode(inode, &wbc); + if (ret < 0) goto out_error; - } - need_commit = test_bit(PG_CLEAN, &req->wb_flags); - nfs_clear_page_tag_locked(req); - if (need_commit) { - ret = nfs_commit_inode(inode, FLUSH_SYNC); - if (ret < 0) - goto out_error; - } } return 0; out_error: -- cgit v1.2.3-70-g09d2