#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"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
+#include "fscache.h"
#ifdef CONFIG_CIFS_POSIX
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)
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)
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff