orangefs: don't bother with splitting iovecs
copy_page_{to,from}_iter() advances it just fine *and* it has no
problem with partially consumed segments.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index 9a439b2..ff7fe37 100644
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -257,168 +257,6 @@
}
/*
- * The reason we need to do this is to be able to support readv and writev
- * that are larger than (pvfs_bufmap_size_query()) Default is
- * PVFS2_BUFMAP_DEFAULT_DESC_SIZE MB. What that means is that we will
- * create a new io vec descriptor for those memory addresses that
- * go beyond the limit. Return value for this routine is negative in case
- * of errors and 0 in case of success.
- *
- * Further, the new_nr_segs pointer is updated to hold the new value
- * of number of iovecs, the new_vec pointer is updated to hold the pointer
- * to the new split iovec, and the size array is an array of integers holding
- * the number of iovecs that straddle pvfs_bufmap_size_query().
- * The max_new_nr_segs value is computed by the caller and returned.
- * (It will be (count of all iov_len/ block_size) + 1).
- */
-static int split_iovecs(unsigned long max_new_nr_segs, /* IN */
- unsigned long nr_segs, /* IN */
- const struct iovec *original_iovec, /* IN */
- unsigned long *new_nr_segs, /* OUT */
- struct iovec **new_vec, /* OUT */
- unsigned long *seg_count, /* OUT */
- unsigned long **seg_array) /* OUT */
-{
- unsigned long seg;
- unsigned long count = 0;
- unsigned long begin_seg;
- unsigned long tmpnew_nr_segs = 0;
- struct iovec *new_iovec = NULL;
- struct iovec *orig_iovec;
- unsigned long *sizes = NULL;
- unsigned long sizes_count = 0;
-
- if (nr_segs <= 0 ||
- original_iovec == NULL ||
- new_nr_segs == NULL ||
- new_vec == NULL ||
- seg_count == NULL ||
- seg_array == NULL ||
- max_new_nr_segs <= 0) {
- gossip_err("Invalid parameters to split_iovecs\n");
- return -EINVAL;
- }
- *new_nr_segs = 0;
- *new_vec = NULL;
- *seg_count = 0;
- *seg_array = NULL;
- /* copy the passed in iovec descriptor to a temp structure */
- orig_iovec = kmalloc_array(nr_segs,
- sizeof(*orig_iovec),
- PVFS2_BUFMAP_GFP_FLAGS);
- if (orig_iovec == NULL) {
- gossip_err(
- "split_iovecs: Could not allocate memory for %lu bytes!\n",
- (unsigned long)(nr_segs * sizeof(*orig_iovec)));
- return -ENOMEM;
- }
- new_iovec = kcalloc(max_new_nr_segs,
- sizeof(*new_iovec),
- PVFS2_BUFMAP_GFP_FLAGS);
- if (new_iovec == NULL) {
- kfree(orig_iovec);
- gossip_err(
- "split_iovecs: Could not allocate memory for %lu bytes!\n",
- (unsigned long)(max_new_nr_segs * sizeof(*new_iovec)));
- return -ENOMEM;
- }
- sizes = kcalloc(max_new_nr_segs,
- sizeof(*sizes),
- PVFS2_BUFMAP_GFP_FLAGS);
- if (sizes == NULL) {
- kfree(new_iovec);
- kfree(orig_iovec);
- gossip_err(
- "split_iovecs: Could not allocate memory for %lu bytes!\n",
- (unsigned long)(max_new_nr_segs * sizeof(*sizes)));
- return -ENOMEM;
- }
- /* copy the passed in iovec to a temp structure */
- memcpy(orig_iovec, original_iovec, nr_segs * sizeof(*orig_iovec));
- begin_seg = 0;
-repeat:
- for (seg = begin_seg; seg < nr_segs; seg++) {
- if (tmpnew_nr_segs >= max_new_nr_segs ||
- sizes_count >= max_new_nr_segs) {
- kfree(sizes);
- kfree(orig_iovec);
- kfree(new_iovec);
- gossip_err
- ("split_iovecs: exceeded the index limit (%lu)\n",
- tmpnew_nr_segs);
- return -EINVAL;
- }
- if (count + orig_iovec[seg].iov_len <
- pvfs_bufmap_size_query()) {
- count += orig_iovec[seg].iov_len;
- memcpy(&new_iovec[tmpnew_nr_segs],
- &orig_iovec[seg],
- sizeof(*new_iovec));
- tmpnew_nr_segs++;
- sizes[sizes_count]++;
- } else {
- new_iovec[tmpnew_nr_segs].iov_base =
- orig_iovec[seg].iov_base;
- new_iovec[tmpnew_nr_segs].iov_len =
- (pvfs_bufmap_size_query() - count);
- tmpnew_nr_segs++;
- sizes[sizes_count]++;
- sizes_count++;
- begin_seg = seg;
- orig_iovec[seg].iov_base +=
- (pvfs_bufmap_size_query() - count);
- orig_iovec[seg].iov_len -=
- (pvfs_bufmap_size_query() - count);
- count = 0;
- break;
- }
- }
- if (seg != nr_segs)
- goto repeat;
- else
- sizes_count++;
-
- *new_nr_segs = tmpnew_nr_segs;
- /* new_iovec is freed by the caller */
- *new_vec = new_iovec;
- *seg_count = sizes_count;
- /* seg_array is also freed by the caller */
- *seg_array = sizes;
- kfree(orig_iovec);
- return 0;
-}
-
-static long bound_max_iovecs(const struct iovec *curr, unsigned long nr_segs,
- ssize_t *total_count)
-{
- unsigned long i;
- long max_nr_iovecs;
- ssize_t total;
- ssize_t count;
-
- total = 0;
- count = 0;
- max_nr_iovecs = 0;
- for (i = 0; i < nr_segs; i++) {
- const struct iovec *iv = &curr[i];
-
- count += iv->iov_len;
- if (unlikely((ssize_t) (count | iv->iov_len) < 0))
- return -EINVAL;
- if (total + iv->iov_len < pvfs_bufmap_size_query()) {
- total += iv->iov_len;
- max_nr_iovecs++;
- } else {
- total =
- (total + iv->iov_len - pvfs_bufmap_size_query());
- max_nr_iovecs += (total / pvfs_bufmap_size_query() + 2);
- }
- }
- *total_count = count;
- return max_nr_iovecs;
-}
-
-/*
* Common entry point for read/write/readv/writev
* This function will dispatch it to either the direct I/O
* or buffered I/O path depending on the mount options and/or
@@ -431,25 +269,10 @@
struct inode *inode = file->f_mapping->host;
struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
struct pvfs2_khandle *handle = &pvfs2_inode->refn.khandle;
- ssize_t ret;
- ssize_t total_count;
- unsigned int to_free;
- size_t count;
- unsigned long seg;
- unsigned long new_nr_segs;
- unsigned long max_new_nr_segs;
- unsigned long seg_count;
- unsigned long *seg_array;
- struct iovec *iovecptr;
- struct iovec *ptr;
-
- total_count = 0;
- ret = -EINVAL;
- count = 0;
- to_free = 0;
-
- /* Compute total and max number of segments after split */
- max_new_nr_segs = bound_max_iovecs(iov, nr_segs, &count);
+ struct iov_iter iter;
+ size_t count = iov_length(iov, nr_segs);
+ ssize_t total_count = 0;
+ ssize_t ret = -EINVAL;
gossip_debug(GOSSIP_FILE_DEBUG,
"%s-BEGIN(%pU): count(%d) after estimate_max_iovecs.\n",
@@ -472,93 +295,10 @@
goto out;
}
- /*
- * if the total size of data transfer requested is greater than
- * the kernel-set blocksize of PVFS2, then we split the iovecs
- * such that no iovec description straddles a block size limit
- */
+ iov_iter_init(&iter, type == PVFS_IO_READ ? READ : WRITE,
+ iov, nr_segs, count);
- gossip_debug(GOSSIP_FILE_DEBUG,
- "%s: pvfs_bufmap_size:%d\n",
- __func__,
- pvfs_bufmap_size_query());
-
- if (count > pvfs_bufmap_size_query()) {
- /*
- * Split up the given iovec description such that
- * no iovec descriptor straddles over the block-size limitation.
- * This makes us our job easier to stage the I/O.
- * In addition, this function will also compute an array
- * with seg_count entries that will store the number of
- * segments that straddle the block-size boundaries.
- */
- ret = split_iovecs(max_new_nr_segs, /* IN */
- nr_segs, /* IN */
- iov, /* IN */
- &new_nr_segs, /* OUT */
- &iovecptr, /* OUT */
- &seg_count, /* OUT */
- &seg_array); /* OUT */
- if (ret < 0) {
- gossip_err("%s: Failed to split iovecs to satisfy larger than blocksize readv/writev request %zd\n",
- __func__,
- ret);
- goto out;
- }
- gossip_debug(GOSSIP_FILE_DEBUG,
- "%s: Splitting iovecs from %lu to %lu"
- " [max_new %lu]\n",
- __func__,
- nr_segs,
- new_nr_segs,
- max_new_nr_segs);
- /* We must free seg_array and iovecptr */
- to_free = 1;
- } else {
- new_nr_segs = nr_segs;
- /* use the given iovec description */
- iovecptr = (struct iovec *)iov;
- /* There is only 1 element in the seg_array */
- seg_count = 1;
- /* and its value is the number of segments passed in */
- seg_array = &nr_segs;
- /* We dont have to free up anything */
- to_free = 0;
- }
- ptr = iovecptr;
-
- gossip_debug(GOSSIP_FILE_DEBUG,
- "%s(%pU) %zd@%llu\n",
- __func__,
- handle,
- count,
- llu(*offset));
- gossip_debug(GOSSIP_FILE_DEBUG,
- "%s(%pU): new_nr_segs: %lu, seg_count: %lu\n",
- __func__,
- handle,
- new_nr_segs, seg_count);
-
-/* PVFS2_KERNEL_DEBUG is a CFLAGS define. */
-#ifdef PVFS2_KERNEL_DEBUG
- for (seg = 0; seg < new_nr_segs; seg++)
- gossip_debug(GOSSIP_FILE_DEBUG,
- "%s: %d) %p to %p [%d bytes]\n",
- __func__,
- (int)seg + 1,
- iovecptr[seg].iov_base,
- iovecptr[seg].iov_base + iovecptr[seg].iov_len,
- (int)iovecptr[seg].iov_len);
- for (seg = 0; seg < seg_count; seg++)
- gossip_debug(GOSSIP_FILE_DEBUG,
- "%s: %zd) %lu\n",
- __func__,
- seg + 1,
- seg_array[seg]);
-#endif
- seg = 0;
while (total_count < count) {
- struct iov_iter iter;
size_t each_count;
size_t amt_complete;
@@ -579,9 +319,6 @@
handle,
(int)*offset);
- iov_iter_init(&iter, type == PVFS_IO_READ ? READ : WRITE,
- ptr, seg_array[seg], each_count);
-
ret = wait_for_direct_io(type, inode, offset, &iter,
each_count, 0);
gossip_debug(GOSSIP_FILE_DEBUG,
@@ -593,9 +330,6 @@
if (ret < 0)
goto out;
- /* advance the iovec pointer */
- ptr += seg_array[seg];
- seg++;
*offset += ret;
total_count += ret;
amt_complete = ret;
@@ -617,10 +351,6 @@
if (total_count > 0)
ret = total_count;
out:
- if (to_free) {
- kfree(iovecptr);
- kfree(seg_array);
- }
if (ret > 0) {
if (type == PVFS_IO_READ) {
file_accessed(file);