On 05/17/2010 08:37 PM, Zhang Jingwang wrote: > 2010/5/17 Boaz Harrosh <bharrosh@xxxxxxxxxxx>: >> On 05/17/2010 12:59 PM, Zhang Jingwang wrote: >>> These two functions mustn't be called from the same workqueue. Otherwise >>> deadlock may occur. So we schedule the return_layout_barrier to nfsiod. >>> nfsiod may not be a good choice, maybe we should setup a new workqueue >>> to do the job. >> >> Please give more information. When does it happen that pnfs_XXX_done will >> return -EAGAIN? > network error or something else. > >> >> What is the stack trace of the deadlock? >> > http://linux-nfs.org/pipermail/pnfs/2010-January/009939.html > I wish you would send me the real stack trace and not the explanations because some things has changed and I could find a way to solve it with the new code. Boaz >> And please rebase that patch on the latest changes to _pnfs_return_layout(). >> but since in the new code _pnfs_return_layout() must be called with NO_WAIT >> if called from the nfsiod then you cannot call pnfs_initiate_write/read() right >> after. For writes you can get by with doing nothing because the write-back >> thread will kick in soon enough. For reads I'm not sure, you'll need to send >> me more information, stack trace. >> >> Or you can wait for the new state machine. > I think the reason of this deadlock is that the put and the wait are > in the same workqueue and run serially. So the state machine will not > help. >> >> Boaz >> >>> >>> Signed-off-by: Zhang Jingwang <zhangjingwang@xxxxxxxxxxxx> >>> --- >>> fs/nfs/pnfs.c | 58 +++++++++++++++++++++++++++++++++++++++----------------- >>> 1 files changed, 40 insertions(+), 18 deletions(-) >>> >>> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c >>> index 5ad7fc6..d2b72be 100644 >>> --- a/fs/nfs/pnfs.c >>> +++ b/fs/nfs/pnfs.c >>> @@ -1655,6 +1655,24 @@ pnfs_call_done(struct pnfs_call_data *pdata, struct rpc_task *task, void *data) >>> * cleanup. >>> */ >>> static void >>> +pnfs_write_retry(struct work_struct *work) >>> +{ >>> + struct rpc_task *task; >>> + struct nfs_write_data *wdata; >>> + struct nfs4_pnfs_layout_segment range; >>> + >>> + dprintk("%s enter\n", __func__); >>> + task = container_of(work, struct rpc_task, u.tk_work); >>> + wdata = container_of(task, struct nfs_write_data, task); >>> + range.iomode = IOMODE_RW; >>> + range.offset = wdata->args.offset; >>> + range.length = wdata->args.count; >>> + _pnfs_return_layout(wdata->inode, &range, NULL, RETURN_FILE); >>> + pnfs_initiate_write(wdata, NFS_CLIENT(wdata->inode), >>> + wdata->pdata.call_ops, wdata->pdata.how); >>> +} >>> + >>> +static void >>> pnfs_writeback_done(struct nfs_write_data *data) >>> { >>> struct pnfs_call_data *pdata = &data->pdata; >>> @@ -1674,15 +1692,8 @@ pnfs_writeback_done(struct nfs_write_data *data) >>> } >>> >>> if (pnfs_call_done(pdata, &data->task, data) == -EAGAIN) { >>> - struct nfs4_pnfs_layout_segment range = { >>> - .iomode = IOMODE_RW, >>> - .offset = data->args.offset, >>> - .length = data->args.count, >>> - }; >>> - dprintk("%s: retrying\n", __func__); >>> - _pnfs_return_layout(data->inode, &range, NULL, RETURN_FILE); >>> - pnfs_initiate_write(data, NFS_CLIENT(data->inode), >>> - pdata->call_ops, pdata->how); >>> + INIT_WORK(&data->task.u.tk_work, pnfs_write_retry); >>> + queue_work(nfsiod_workqueue, &data->task.u.tk_work); >>> } >>> } >>> >>> @@ -1798,6 +1809,24 @@ out: >>> * read_pagelist is done >>> */ >>> static void >>> +pnfs_read_retry(struct work_struct *work) >>> +{ >>> + struct rpc_task *task; >>> + struct nfs_read_data *rdata; >>> + struct nfs4_pnfs_layout_segment range; >>> + >>> + dprintk("%s enter\n", __func__); >>> + task = container_of(work, struct rpc_task, u.tk_work); >>> + rdata = container_of(task, struct nfs_read_data, task); >>> + range.iomode = IOMODE_RW; >>> + range.offset = rdata->args.offset; >>> + range.length = rdata->args.count; >>> + _pnfs_return_layout(rdata->inode, &range, NULL, RETURN_FILE); >>> + pnfs_initiate_read(rdata, NFS_CLIENT(rdata->inode), >>> + rdata->pdata.call_ops); >>> +} >>> + >>> +static void >>> pnfs_read_done(struct nfs_read_data *data) >>> { >>> struct pnfs_call_data *pdata = &data->pdata; >>> @@ -1805,15 +1834,8 @@ pnfs_read_done(struct nfs_read_data *data) >>> dprintk("%s: Begin (status %d)\n", __func__, data->task.tk_status); >>> >>> if (pnfs_call_done(pdata, &data->task, data) == -EAGAIN) { >>> - struct nfs4_pnfs_layout_segment range = { >>> - .iomode = IOMODE_ANY, >>> - .offset = data->args.offset, >>> - .length = data->args.count, >>> - }; >>> - dprintk("%s: retrying\n", __func__); >>> - _pnfs_return_layout(data->inode, &range, NULL, RETURN_FILE); >>> - pnfs_initiate_read(data, NFS_CLIENT(data->inode), >>> - pdata->call_ops); >>> + INIT_WORK(&data->task.u.tk_work, pnfs_read_retry); >>> + queue_work(nfsiod_workqueue, &data->task.u.tk_work); >>> } >>> } >>> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
