diff options
Diffstat (limited to 'fs/cifs/cifssmb.c')
-rw-r--r-- | fs/cifs/cifssmb.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 0613df4..aaad4ce 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -33,6 +33,8 @@ #include <linux/slab.h> #include <linux/posix_acl_xattr.h> #include <linux/pagemap.h> +#include <linux/swap.h> +#include <linux/task_io_accounting_ops.h> #include <asm/uaccess.h> #include "cifspdu.h" #include "cifsglob.h" @@ -40,6 +42,7 @@ #include "cifsproto.h" #include "cifs_unicode.h" #include "cifs_debug.h" +#include "fscache.h" #ifdef CONFIG_CIFS_POSIX static struct { @@ -83,6 +86,9 @@ static struct { #endif /* CONFIG_CIFS_WEAK_PW_HASH */ #endif /* CIFS_POSIX */ +/* Forward declarations */ +static void cifs_readv_complete(struct work_struct *work); + /* Mark as invalid, all open files on tree connections since they were closed when session to server was lost */ static void mark_open_files_invalid(struct cifs_tcon *pTcon) @@ -1375,6 +1381,359 @@ openRetry: return rc; } +struct cifs_readdata * +cifs_readdata_alloc(unsigned int nr_pages) +{ + struct cifs_readdata *rdata; + + /* readdata + 1 kvec for each page */ + rdata = kzalloc(sizeof(*rdata) + + sizeof(struct kvec) * nr_pages, GFP_KERNEL); + if (rdata != NULL) { + INIT_WORK(&rdata->work, cifs_readv_complete); + INIT_LIST_HEAD(&rdata->pages); + } + return rdata; +} + +void +cifs_readdata_free(struct cifs_readdata *rdata) +{ + cifsFileInfo_put(rdata->cfile); + kfree(rdata); +} + +/* + * Discard any remaining data in the current SMB. To do this, we borrow the + * current bigbuf. + */ +static int +cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid) +{ + READ_RSP *rsp = (READ_RSP *)server->smallbuf; + unsigned int rfclen = be32_to_cpu(rsp->hdr.smb_buf_length); + int remaining = rfclen + 4 - server->total_read; + struct cifs_readdata *rdata = mid->callback_data; + + while (remaining > 0) { + int length; + + length = cifs_read_from_socket(server, server->bigbuf, + min_t(unsigned int, remaining, + CIFSMaxBufSize + MAX_CIFS_HDR_SIZE)); + if (length < 0) + return length; + server->total_read += length; + remaining -= length; + } + + dequeue_mid(mid, rdata->result); + return 0; +} + +static int +cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) +{ + int length, len; + unsigned int data_offset, remaining, data_len; + struct cifs_readdata *rdata = mid->callback_data; + READ_RSP *rsp = (READ_RSP *)server->smallbuf; + unsigned int rfclen = be32_to_cpu(rsp->hdr.smb_buf_length) + 4; + u64 eof; + pgoff_t eof_index; + struct page *page, *tpage; + + cFYI(1, "%s: mid=%u offset=%llu bytes=%u", __func__, + mid->mid, rdata->offset, rdata->bytes); + + /* + * read the rest of READ_RSP header (sans Data array), or whatever we + * can if there's not enough data. At this point, we've read down to + * the Mid. + */ + len = min_t(unsigned int, rfclen, sizeof(*rsp)) - + sizeof(struct smb_hdr) + 1; + + rdata->iov[0].iov_base = server->smallbuf + sizeof(struct smb_hdr) - 1; + rdata->iov[0].iov_len = len; + + length = cifs_readv_from_socket(server, rdata->iov, 1, len); + if (length < 0) + return length; + server->total_read += length; + + /* Was the SMB read successful? */ + rdata->result = map_smb_to_linux_error(&rsp->hdr, false); + if (rdata->result != 0) { + cFYI(1, "%s: server returned error %d", __func__, + rdata->result); + return cifs_readv_discard(server, mid); + } + + /* Is there enough to get to the rest of the READ_RSP header? */ + if (server->total_read < sizeof(READ_RSP)) { + cFYI(1, "%s: server returned short header. got=%u expected=%zu", + __func__, server->total_read, sizeof(READ_RSP)); + rdata->result = -EIO; + return cifs_readv_discard(server, mid); + } + + data_offset = le16_to_cpu(rsp->DataOffset) + 4; + if (data_offset < server->total_read) { + /* + * win2k8 sometimes sends an offset of 0 when the read + * is beyond the EOF. Treat it as if the data starts just after + * the header. + */ + cFYI(1, "%s: data offset (%u) inside read response header", + __func__, data_offset); + data_offset = server->total_read; + } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) { + /* data_offset is beyond the end of smallbuf */ + cFYI(1, "%s: data offset (%u) beyond end of smallbuf", + __func__, data_offset); + rdata->result = -EIO; + return cifs_readv_discard(server, mid); + } + + cFYI(1, "%s: total_read=%u data_offset=%u", __func__, + server->total_read, data_offset); + + len = data_offset - server->total_read; + if (len > 0) { + /* read any junk before data into the rest of smallbuf */ + rdata->iov[0].iov_base = server->smallbuf + server->total_read; + rdata->iov[0].iov_len = len; + length = cifs_readv_from_socket(server, rdata->iov, 1, len); + if (length < 0) + return length; + server->total_read += length; + } + + /* set up first iov for signature check */ + rdata->iov[0].iov_base = server->smallbuf; + rdata->iov[0].iov_len = server->total_read; + cFYI(1, "0: iov_base=%p iov_len=%zu", + rdata->iov[0].iov_base, rdata->iov[0].iov_len); + + /* how much data is in the response? */ + data_len = le16_to_cpu(rsp->DataLengthHigh) << 16; + data_len += le16_to_cpu(rsp->DataLength); + if (data_offset + data_len > rfclen) { + /* data_len is corrupt -- discard frame */ + rdata->result = -EIO; + return cifs_readv_discard(server, mid); + } + + /* marshal up the page array */ + len = 0; + remaining = data_len; + rdata->nr_iov = 1; + + /* determine the eof that the server (probably) has */ + eof = CIFS_I(rdata->mapping->host)->server_eof; + eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0; + cFYI(1, "eof=%llu eof_index=%lu", eof, eof_index); + + list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { + if (remaining >= PAGE_CACHE_SIZE) { + /* enough data to fill the page */ + rdata->iov[rdata->nr_iov].iov_base = kmap(page); + rdata->iov[rdata->nr_iov].iov_len = PAGE_CACHE_SIZE; + cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu", + rdata->nr_iov, page->index, + rdata->iov[rdata->nr_iov].iov_base, + rdata->iov[rdata->nr_iov].iov_len); + ++rdata->nr_iov; + len += PAGE_CACHE_SIZE; + remaining -= PAGE_CACHE_SIZE; + } else if (remaining > 0) { + /* enough for partial page, fill and zero the rest */ + rdata->iov[rdata->nr_iov].iov_base = kmap(page); + rdata->iov[rdata->nr_iov].iov_len = remaining; + cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu", + rdata->nr_iov, page->index, + rdata->iov[rdata->nr_iov].iov_base, + rdata->iov[rdata->nr_iov].iov_len); + memset(rdata->iov[rdata->nr_iov].iov_base + remaining, + '\0', PAGE_CACHE_SIZE - remaining); + ++rdata->nr_iov; + len += remaining; + remaining = 0; + } else if (page->index > eof_index) { + /* + * The VFS will not try to do readahead past the + * i_size, but it's possible that we have outstanding + * writes with gaps in the middle and the i_size hasn't + * caught up yet. Populate those with zeroed out pages + * to prevent the VFS from repeatedly attempting to + * fill them until the writes are flushed. + */ + zero_user(page, 0, PAGE_CACHE_SIZE); + list_del(&page->lru); + lru_cache_add_file(page); + flush_dcache_page(page); + SetPageUptodate(page); + unlock_page(page); + page_cache_release(page); + } else { + /* no need to hold page hostage */ + list_del(&page->lru); + lru_cache_add_file(page); + unlock_page(page); + page_cache_release(page); + } + } + + /* issue the read if we have any iovecs left to fill */ + if (rdata->nr_iov > 1) { + length = cifs_readv_from_socket(server, &rdata->iov[1], + rdata->nr_iov - 1, len); + if (length < 0) + return length; + server->total_read += length; + } else { + length = 0; + } + + rdata->bytes = length; + + cFYI(1, "total_read=%u rfclen=%u remaining=%u", server->total_read, + rfclen, remaining); + + /* discard anything left over */ + if (server->total_read < rfclen) + return cifs_readv_discard(server, mid); + + dequeue_mid(mid, false); + return length; +} + +static void +cifs_readv_complete(struct work_struct *work) +{ + struct cifs_readdata *rdata = container_of(work, + struct cifs_readdata, work); + struct page *page, *tpage; + + list_for_each_entry_safe(page, tpage, &rdata->pages, lru) { + list_del(&page->lru); + lru_cache_add_file(page); + kunmap(page); + + if (rdata->result == 0) { + flush_dcache_page(page); + SetPageUptodate(page); + } + + unlock_page(page); + + if (rdata->result == 0) + cifs_readpage_to_fscache(rdata->mapping->host, page); + + page_cache_release(page); + } + cifs_readdata_free(rdata); +} + +static void +cifs_readv_callback(struct mid_q_entry *mid) +{ + struct cifs_readdata *rdata = mid->callback_data; + struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink); + struct TCP_Server_Info *server = tcon->ses->server; + + cFYI(1, "%s: mid=%u state=%d result=%d bytes=%u", __func__, + mid->mid, mid->midState, rdata->result, rdata->bytes); + + switch (mid->midState) { + case MID_RESPONSE_RECEIVED: + /* result already set, check signature */ + if (server->sec_mode & + (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) { + if (cifs_verify_signature(rdata->iov, rdata->nr_iov, + server, mid->sequence_number + 1)) + cERROR(1, "Unexpected SMB signature"); + } + /* FIXME: should this be counted toward the initiating task? */ + task_io_account_read(rdata->bytes); + cifs_stats_bytes_read(tcon, rdata->bytes); + break; + case MID_REQUEST_SUBMITTED: + case MID_RETRY_NEEDED: + rdata->result = -EAGAIN; + break; + default: + rdata->result = -EIO; + } + + queue_work(system_nrt_wq, &rdata->work); + DeleteMidQEntry(mid); + atomic_dec(&server->inFlight); + wake_up(&server->request_q); +} + +/* cifs_async_readv - send an async write, and set up mid to handle result */ +int +cifs_async_readv(struct cifs_readdata *rdata) +{ + int rc; + READ_REQ *smb = NULL; + int wct; + struct cifs_tcon *tcon = tlink_tcon(rdata->cfile->tlink); + + cFYI(1, "%s: offset=%llu bytes=%u", __func__, + rdata->offset, rdata->bytes); + + if (tcon->ses->capabilities & CAP_LARGE_FILES) + wct = 12; + else { + wct = 10; /* old style read */ + if ((rdata->offset >> 32) > 0) { + /* can not handle this big offset for old */ + return -EIO; + } + } + + rc = small_smb_init(SMB_COM_READ_ANDX, wct, tcon, (void **)&smb); + if (rc) + return rc; + + smb->hdr.Pid = cpu_to_le16((__u16)rdata->pid); + smb->hdr.PidHigh = cpu_to_le16((__u16)(rdata->pid >> 16)); + + smb->AndXCommand = 0xFF; /* none */ + smb->Fid = rdata->cfile->netfid; + smb->OffsetLow = cpu_to_le32(rdata->offset & 0xFFFFFFFF); + if (wct == 12) + smb->OffsetHigh = cpu_to_le32(rdata->offset >> 32); + smb->Remaining = 0; + smb->MaxCount = cpu_to_le16(rdata->bytes & 0xFFFF); + smb->MaxCountHigh = cpu_to_le32(rdata->bytes >> 16); + if (wct == 12) + smb->ByteCount = 0; + else { + /* old style read */ + struct smb_com_readx_req *smbr = + (struct smb_com_readx_req *)smb; + smbr->ByteCount = 0; + } + + /* 4 for RFC1001 length + 1 for BCC */ + rdata->iov[0].iov_base = smb; + rdata->iov[0].iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4; + + rc = cifs_call_async(tcon->ses->server, rdata->iov, 1, + cifs_readv_receive, cifs_readv_callback, + rdata, false); + + if (rc == 0) + cifs_stats_inc(&tcon->num_reads); + + cifs_small_buf_release(smb); + return rc; +} + int CIFSSMBRead(const int xid, struct cifs_io_parms *io_parms, unsigned int *nbytes, char **buf, int *pbuf_type) |