Add the ability for CIFS to do an asynchronous write. The kernel will set the frame up as it would for a "normal" SMBWrite2 request, and use cifs_call_async to send it. The mid callback will then be configured to handle the result.
Signed-off-by: Jeff Layton <[email protected]> --- fs/cifs/cifsproto.h | 19 +++++ fs/cifs/cifssmb.c | 219 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 238 insertions(+), 0 deletions(-) diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index e255a2b..7b964df 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -21,6 +21,7 @@ #ifndef _CIFSPROTO_H #define _CIFSPROTO_H #include <linux/nls.h> +#include <linux/pagevec.h> struct statfs; struct smb_vol; @@ -433,4 +434,22 @@ extern int mdfour(unsigned char *, unsigned char *, int); extern int E_md4hash(const unsigned char *passwd, unsigned char *p16); extern int SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24); + +/* asynchronous write support */ +struct cifs_writedata { + struct list_head pending; + struct kref refcount; + struct completion completion; + struct work_struct work; + struct cifsFileInfo *cfile; + __u64 offset; + unsigned int bytes; + int result; + struct page *pages[PAGEVEC_SIZE]; +}; + +int cifs_async_writev(struct cifs_writedata *wdata); +struct cifs_writedata *cifs_writedata_alloc(void); +void cifs_writedata_release(struct kref *refcount); + #endif /* _CIFSPROTO_H */ diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 8de7e79..b308605 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -32,6 +32,7 @@ #include <linux/vfs.h> #include <linux/slab.h> #include <linux/posix_acl_xattr.h> +#include <linux/pagemap.h> #include <asm/uaccess.h> #include "cifspdu.h" #include "cifsglob.h" @@ -1604,6 +1605,224 @@ CIFSSMBWrite(const int xid, struct cifs_tcon *tcon, return rc; } +void +cifs_writedata_release(struct kref *refcount) +{ + struct cifs_writedata *wdata = container_of(refcount, + struct cifs_writedata, refcount); + struct address_space *mapping; + + if (wdata->cfile) { + mapping = wdata->cfile->dentry->d_inode->i_mapping; + + spin_lock(&mapping->private_lock); + list_del(&wdata->pending); + spin_unlock(&mapping->private_lock); + + cifsFileInfo_put(wdata->cfile); + } + + kfree(wdata); +} + +static void +cifs_writev_complete(struct work_struct *work) +{ + struct cifs_writedata *wdata = container_of(work, + struct cifs_writedata, work); + struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink); + struct inode *inode = wdata->cfile->dentry->d_inode; + struct page *page; + int i = 0; + + if (wdata->result == 0) { + cifs_update_eof(CIFS_I(inode), wdata->offset, wdata->bytes); + cifs_stats_bytes_written(tcon, wdata->bytes); + } + + for (i = 0; i < ARRAY_SIZE(wdata->pages) && (page = wdata->pages[i]); + i++) { + if (wdata->result == -EAGAIN) + __set_page_dirty_nobuffers(page); + else if (wdata->result < 0) + SetPageError(page); + end_page_writeback(page); + page_cache_release(page); + } + if (wdata->result != -EAGAIN) + mapping_set_error(inode->i_mapping, wdata->result); + complete(&wdata->completion); + kref_put(&wdata->refcount, cifs_writedata_release); +} + +struct cifs_writedata * +cifs_writedata_alloc(void) +{ + struct cifs_writedata *wdata; + + wdata = kzalloc(sizeof(*wdata), GFP_NOFS); + if (wdata != NULL) { + INIT_LIST_HEAD(&wdata->pending); + INIT_WORK(&wdata->work, cifs_writev_complete); + kref_init(&wdata->refcount); + init_completion(&wdata->completion); + } + return wdata; +} + +/* + * Check the midState and signature on received buffer (if any), and queue the + * workqueue completion task. + */ +static void +cifs_writev_callback(struct mid_q_entry *mid) +{ + struct cifs_writedata *wdata = mid->callback_data; + struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink); + unsigned int written; + WRITE_RSP *smb = (WRITE_RSP *)mid->resp_buf; + + switch(mid->midState) { + case MID_RESPONSE_RECEIVED: + wdata->result = cifs_check_receive(mid, tcon->ses->server, 0); + if (wdata->result != 0) + break; + + written = le16_to_cpu(smb->CountHigh); + written <<= 16; + written += le16_to_cpu(smb->Count); + /* + * Mask off high 16 bits when bytes written as returned + * by the server is greater than bytes requested by the + * client. OS/2 servers are known to set incorrect + * CountHigh values. + */ + if (written > wdata->bytes) + written &= 0xFFFF; + + if (written < wdata->bytes) + wdata->result = -ENOSPC; + else + wdata->bytes = written; + break; + case MID_REQUEST_SUBMITTED: + case MID_RETRY_NEEDED: + wdata->result = -EAGAIN; + break; + default: + wdata->result = -EIO; + break; + } + + queue_work(system_nrt_wq, &wdata->work); + DeleteMidQEntry(mid); + atomic_dec(&tcon->ses->server->inFlight); + wake_up(&tcon->ses->server->request_q); +} + +/* cifs_async_writev - send an async write, and set up mid to handle result */ +int +cifs_async_writev(struct cifs_writedata *wdata) +{ + int i, rc = -EACCES; + WRITE_REQ *smb = NULL; + int wct; + struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink); + struct inode *inode = wdata->cfile->dentry->d_inode; + unsigned int npages = ARRAY_SIZE(wdata->pages); + struct kvec *iov = NULL; + + cFYI(1, "async write at %llu %u bytes", wdata->offset, wdata->bytes); + + if (tcon->ses->capabilities & CAP_LARGE_FILES) { + wct = 14; + } else { + wct = 12; + if (wdata->offset >> 32 > 0) { + /* can not handle big offset for old srv */ + return -EIO; + } + } + + rc = small_smb_init(SMB_COM_WRITE_ANDX, wct, tcon, (void **)&smb); + if (rc) + goto async_writev_out; + + /* FIXME: only allocate number of kvecs we need */ + iov = kzalloc((npages + 1) * sizeof(*iov), GFP_NOFS); + if (iov == NULL) { + rc = -ENOMEM; + goto async_writev_out; + } + + smb->AndXCommand = 0xFF; /* none */ + smb->Fid = wdata->cfile->netfid; + smb->OffsetLow = cpu_to_le32(wdata->offset & 0xFFFFFFFF); + if (wct == 14) + smb->OffsetHigh = cpu_to_le32(wdata->offset >> 32); + smb->Reserved = 0xFFFFFFFF; + smb->WriteMode = 0; + smb->Remaining = 0; + + smb->DataOffset = + cpu_to_le16(offsetof(struct smb_com_write_req, Data) - 4); + + /* 4 for RFC1001 length + 1 for BCC */ + iov[0].iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4 + 1; + iov[0].iov_base = smb; + + /* marshal up the pages into iov array */ + npages = 0; + wdata->bytes = 0; + for (i = 0; i < ARRAY_SIZE(wdata->pages) && wdata->pages[i]; i++) { + if (wdata->bytes + PAGE_CACHE_SIZE <= + CIFS_SB(inode->i_sb)->wsize) { + iov[i + 1].iov_len = min(inode->i_size - + page_offset(wdata->pages[i]), + (loff_t)PAGE_CACHE_SIZE); + iov[i + 1].iov_base = kmap(wdata->pages[i]); + wdata->bytes += iov[i + 1].iov_len; + npages++; + } else { + /* if we're beyond wsize, then re-mark page dirty */ + __set_page_dirty_nobuffers(wdata->pages[i]); + } + } + + smb->DataLengthLow = cpu_to_le16(wdata->bytes & 0xFFFF); + smb->DataLengthHigh = cpu_to_le16(wdata->bytes >> 16); + + if (wct == 14) { + inc_rfc1001_len(&smb->hdr, wdata->bytes + 1); + put_bcc(wdata->bytes + 1, &smb->hdr); + } else { + /* wct == 12 */ + struct smb_com_writex_req *smbw = + (struct smb_com_writex_req *)smb; + inc_rfc1001_len(&smbw->hdr, wdata->bytes + 5); + put_bcc(wdata->bytes + 5, &smbw->hdr); + iov[0].iov_len += 4; /* pad bigger by four bytes */ + } + + kref_get(&wdata->refcount); + rc = cifs_call_async(tcon->ses->server, iov, npages + 1, + cifs_writev_callback, wdata); + + if (rc == 0) + cifs_stats_inc(&tcon->stats.cifs_stats.num_writes); + else + kref_put(&wdata->refcount, cifs_writedata_release); + + /* send is done, unmap pages */ + for (i = 0; i < npages; i++) + kunmap(wdata->pages[i]); + +async_writev_out: + cifs_small_buf_release(smb); + kfree(iov); + return rc; +} + int CIFSSMBWrite2(const int xid, struct cifs_tcon *tcon, const int netfid, const unsigned int count, -- 1.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
