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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 12:38:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 12:38:28 -0700
commit2017bd19454ea7cdae19922d15b6930f6c8088a2 (patch)
tree53974657ab3a2c98f2da7b3fcb050ff5b697f876 /net/ceph/pagevec.c
parent9f1ad09493451c19d00c004da479acf699eeedd6 (diff)
parentefa4c1206eaff047c474af2136748a58eb8cc33b (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (22 commits) ceph: do not carry i_lock for readdir from dcache fs/ceph/xattr.c: Use kmemdup rbd: passing wrong variable to bvec_kunmap_irq() rbd: null vs ERR_PTR ceph: fix num_pages_free accounting in pagelist ceph: add CEPH_MDS_OP_SETDIRLAYOUT and associated ioctl. ceph: don't crash when passed bad mount options ceph: fix debugfs warnings block: rbd: removing unnecessary test block: rbd: fixed may leaks ceph: switch from BKL to lock_flocks() ceph: preallocate flock state without locks held ceph: add pagelist_reserve, pagelist_truncate, pagelist_set_cursor ceph: use mapping->nrpages to determine if mapping is empty ceph: only invalidate on check_caps if we actually have pages ceph: do not hide .snap in root directory rbd: introduce rados block device (rbd), based on libceph ceph: factor out libceph from Ceph file system ceph-rbd: osdc support for osd call and rollback operations ceph: messenger and osdc changes for rbd ...
Diffstat (limited to 'net/ceph/pagevec.c')
-rw-r--r--net/ceph/pagevec.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
new file mode 100644
index 00000000000..54caf068715
--- /dev/null
+++ b/net/ceph/pagevec.c
@@ -0,0 +1,223 @@
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/namei.h>
+#include <linux/writeback.h>
+
+#include <linux/ceph/libceph.h>
+
+/*
+ * build a vector of user pages
+ */
+struct page **ceph_get_direct_page_vector(const char __user *data,
+ int num_pages,
+ loff_t off, size_t len)
+{
+ struct page **pages;
+ int rc;
+
+ pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
+ if (!pages)
+ return ERR_PTR(-ENOMEM);
+
+ down_read(&current->mm->mmap_sem);
+ rc = get_user_pages(current, current->mm, (unsigned long)data,
+ num_pages, 0, 0, pages, NULL);
+ up_read(&current->mm->mmap_sem);
+ if (rc < 0)
+ goto fail;
+ return pages;
+
+fail:
+ kfree(pages);
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL(ceph_get_direct_page_vector);
+
+void ceph_put_page_vector(struct page **pages, int num_pages)
+{
+ int i;
+
+ for (i = 0; i < num_pages; i++)
+ put_page(pages[i]);
+ kfree(pages);
+}
+EXPORT_SYMBOL(ceph_put_page_vector);
+
+void ceph_release_page_vector(struct page **pages, int num_pages)
+{
+ int i;
+
+ for (i = 0; i < num_pages; i++)
+ __free_pages(pages[i], 0);
+ kfree(pages);
+}
+EXPORT_SYMBOL(ceph_release_page_vector);
+
+/*
+ * allocate a vector new pages
+ */
+struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
+{
+ struct page **pages;
+ int i;
+
+ pages = kmalloc(sizeof(*pages) * num_pages, flags);
+ if (!pages)
+ return ERR_PTR(-ENOMEM);
+ for (i = 0; i < num_pages; i++) {
+ pages[i] = __page_cache_alloc(flags);
+ if (pages[i] == NULL) {
+ ceph_release_page_vector(pages, i);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ return pages;
+}
+EXPORT_SYMBOL(ceph_alloc_page_vector);
+
+/*
+ * copy user data into a page vector
+ */
+int ceph_copy_user_to_page_vector(struct page **pages,
+ const char __user *data,
+ loff_t off, size_t len)
+{
+ int i = 0;
+ int po = off & ~PAGE_CACHE_MASK;
+ int left = len;
+ int l, bad;
+
+ while (left > 0) {
+ l = min_t(int, PAGE_CACHE_SIZE-po, left);
+ bad = copy_from_user(page_address(pages[i]) + po, data, l);
+ if (bad == l)
+ return -EFAULT;
+ data += l - bad;
+ left -= l - bad;
+ po += l - bad;
+ if (po == PAGE_CACHE_SIZE) {
+ po = 0;
+ i++;
+ }
+ }
+ return len;
+}
+EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
+
+int ceph_copy_to_page_vector(struct page **pages,
+ const char *data,
+ loff_t off, size_t len)
+{
+ int i = 0;
+ size_t po = off & ~PAGE_CACHE_MASK;
+ size_t left = len;
+ size_t l;
+
+ while (left > 0) {
+ l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
+ memcpy(page_address(pages[i]) + po, data, l);
+ data += l;
+ left -= l;
+ po += l;
+ if (po == PAGE_CACHE_SIZE) {
+ po = 0;
+ i++;
+ }
+ }
+ return len;
+}
+EXPORT_SYMBOL(ceph_copy_to_page_vector);
+
+int ceph_copy_from_page_vector(struct page **pages,
+ char *data,
+ loff_t off, size_t len)
+{
+ int i = 0;
+ size_t po = off & ~PAGE_CACHE_MASK;
+ size_t left = len;
+ size_t l;
+
+ while (left > 0) {
+ l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
+ memcpy(data, page_address(pages[i]) + po, l);
+ data += l;
+ left -= l;
+ po += l;
+ if (po == PAGE_CACHE_SIZE) {
+ po = 0;
+ i++;
+ }
+ }
+ return len;
+}
+EXPORT_SYMBOL(ceph_copy_from_page_vector);
+
+/*
+ * copy user data from a page vector into a user pointer
+ */
+int ceph_copy_page_vector_to_user(struct page **pages,
+ char __user *data,
+ loff_t off, size_t len)
+{
+ int i = 0;
+ int po = off & ~PAGE_CACHE_MASK;
+ int left = len;
+ int l, bad;
+
+ while (left > 0) {
+ l = min_t(int, left, PAGE_CACHE_SIZE-po);
+ bad = copy_to_user(data, page_address(pages[i]) + po, l);
+ if (bad == l)
+ return -EFAULT;
+ data += l - bad;
+ left -= l - bad;
+ if (po) {
+ po += l - bad;
+ if (po == PAGE_CACHE_SIZE)
+ po = 0;
+ }
+ i++;
+ }
+ return len;
+}
+EXPORT_SYMBOL(ceph_copy_page_vector_to_user);
+
+/*
+ * Zero an extent within a page vector. Offset is relative to the
+ * start of the first page.
+ */
+void ceph_zero_page_vector_range(int off, int len, struct page **pages)
+{
+ int i = off >> PAGE_CACHE_SHIFT;
+
+ off &= ~PAGE_CACHE_MASK;
+
+ dout("zero_page_vector_page %u~%u\n", off, len);
+
+ /* leading partial page? */
+ if (off) {
+ int end = min((int)PAGE_CACHE_SIZE, off + len);
+ dout("zeroing %d %p head from %d\n", i, pages[i],
+ (int)off);
+ zero_user_segment(pages[i], off, end);
+ len -= (end - off);
+ i++;
+ }
+ while (len >= PAGE_CACHE_SIZE) {
+ dout("zeroing %d %p len=%d\n", i, pages[i], len);
+ zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
+ len -= PAGE_CACHE_SIZE;
+ i++;
+ }
+ /* trailing partial page? */
+ if (len) {
+ dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
+ zero_user_segment(pages[i], 0, len);
+ }
+}
+EXPORT_SYMBOL(ceph_zero_page_vector_range);
+