}
static ssize_t ll_file_copy_pages(struct page **pages, int numpages,
- char *buf, loff_t pos, size_t count,
+ const struct iovec *iov, unsigned long nsegs,
+ ssize_t iov_offset, loff_t pos, size_t count,
int rw)
{
ssize_t amount = 0;
ENTRY;
for (i = 0; i < numpages; i++) {
- unsigned offset, bytes, left;
+ unsigned offset, bytes, left = 0;
char *vaddr;
vaddr = kmap(pages[i]);
offset = pos & (CFS_PAGE_SIZE - 1);
bytes = min_t(unsigned, CFS_PAGE_SIZE - offset, count);
LL_CDEBUG_PAGE(D_PAGE, pages[i], "op = %s, addr = %p, "
- "buf = %p, bytes = %u\n",
+ "bytes = %u\n",
(rw == WRITE) ? "CFU" : "CTU",
- vaddr + offset, buf, bytes);
- if (rw == WRITE) {
- left = copy_from_user(vaddr + offset, buf, bytes);
- if (updatechecksum) {
- struct ll_async_page *llap;
-
- llap = llap_cast_private(pages[i]);
- llap->llap_checksum =
- init_checksum(OSC_DEFAULT_CKSUM);
- llap->llap_checksum =
- compute_checksum(llap->llap_checksum,
- vaddr, CFS_PAGE_SIZE,
- OSC_DEFAULT_CKSUM);
+ vaddr + offset, bytes);
+ while (bytes > 0 && !left && nsegs) {
+ unsigned copy = min_t(ssize_t, bytes,
+ iov->iov_len - iov_offset);
+ if (rw == WRITE) {
+ left = copy_from_user(vaddr + offset,
+ iov->iov_base +iov_offset,
+ copy);
+ if (updatechecksum) {
+ struct ll_async_page *llap;
+
+ llap = llap_cast_private(pages[i]);
+ llap->llap_checksum =
+ init_checksum(OSC_DEFAULT_CKSUM);
+ llap->llap_checksum =
+ compute_checksum(llap->llap_checksum,
+ vaddr,CFS_PAGE_SIZE,
+ OSC_DEFAULT_CKSUM);
+ }
+ } else {
+ left = copy_to_user(iov->iov_base + iov_offset,
+ vaddr + offset, copy);
+ }
+
+ amount += copy;
+ count -= copy;
+ pos += copy;
+ iov_offset += copy;
+ bytes -= copy;
+ if (iov_offset == iov->iov_len) {
+ iov_offset = 0;
+ iov++;
+ nsegs--;
}
- } else {
- left = copy_to_user(buf, vaddr + offset, bytes);
}
kunmap(pages[i]);
- amount += bytes;
if (left) {
amount -= left;
break;
}
- buf += bytes;
- count -= bytes;
- pos += bytes;
}
if (amount == 0)
RETURN(-EFAULT);
RETURN(rc);
}
-ssize_t ll_file_lockless_io(struct file *file, char *buf, size_t count,
- loff_t *ppos, int rw)
+/* Advance through passed iov, adjust iov pointer as necessary and return
+ * starting offset in individual entry we are pointing at. Also reduce
+ * nr_segs as needed */
+static ssize_t ll_iov_advance(const struct iovec **iov, unsigned long *nr_segs,
+ ssize_t offset)
+{
+ while (*nr_segs > 0) {
+ if ((*iov)->iov_len > offset)
+ return ((*iov)->iov_len - offset);
+ offset -= (*iov)->iov_len;
+ (*iov)++;
+ (*nr_segs)--;
+ }
+ return 0;
+}
+
+ssize_t ll_file_lockless_io(struct file *file, const struct iovec *iov,
+ unsigned long nr_segs,
+ loff_t *ppos, int rw, ssize_t count)
{
loff_t pos;
struct inode *inode = file->f_dentry->d_inode;
int max_pages;
size_t amount = 0;
unsigned long first, last;
+ const struct iovec *iv = &iov[0];
+ unsigned long nsegs = nr_segs;
+ unsigned long offset = 0;
ENTRY;
if (rw == READ) {
if (rc)
GOTO(out, rc);
}
+
pos = *ppos;
first = pos >> CFS_PAGE_SHIFT;
last = (pos + count - 1) >> CFS_PAGE_SHIFT;
break;
}
if (rw == WRITE) {
- rc = ll_file_copy_pages(pages, pages_for_io, buf,
- pos + amount, bytes, rw);
+ rc = ll_file_copy_pages(pages, pages_for_io, iv, nsegs,
+ offset, pos + amount, bytes,
+ rw);
if (rc < 0)
GOTO(put_pages, rc);
+ offset = ll_iov_advance(&iv, &nsegs, offset + rc);
bytes = rc;
}
rc = ll_file_oig_pages(inode, pages, pages_for_io,
if (rc)
GOTO(put_pages, rc);
if (rw == READ) {
- rc = ll_file_copy_pages(pages, pages_for_io, buf,
- pos + amount, bytes, rw);
+ rc = ll_file_copy_pages(pages, pages_for_io, iv, nsegs,
+ offset, pos + amount, bytes, rw);
if (rc < 0)
GOTO(put_pages, rc);
+ offset = ll_iov_advance(&iv, &nsegs, offset + rc);
bytes = rc;
}
amount += bytes;
- buf += bytes;
put_pages:
ll_file_put_pages(pages, pages_for_io);
first += pages_for_io;
/* a short read/write check */
if (pos + amount < ((loff_t)first << CFS_PAGE_SHIFT))
break;
+ /* Check if we are out of userspace buffers. (how that could
+ happen?) */
+ if (nsegs == 0)
+ break;
}
/* NOTE: don't update i_size and KMS in absence of LDLM locks even
* write makes the file large */
file_accessed(file);
if (rw == READ && amount < count && rc == 0) {
unsigned long not_cleared;
-
- not_cleared = clear_user(buf, count - amount);
- amount = count - not_cleared;
- if (not_cleared)
- rc = -EFAULT;
+
+ while (nsegs > 0) {
+ ssize_t to_clear = min_t(ssize_t, count - amount,
+ iv->iov_len - offset);
+ not_cleared = clear_user(iv->iov_base + offset,
+ to_clear);
+ amount += to_clear - not_cleared;
+ if (not_cleared) {
+ rc = -EFAULT;
+ break;
+ }
+ offset = 0;
+ iv++;
+ nsegs--;
+ }
}
if (amount > 0) {
lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
git://git.whamcloud.com / fs / lustre-release.git / blobdiff