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Orangef: implement orangefs_readahead.
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Also remove open-coded readahead logic from orangefs_readpage.

Signed-off-by: Mike Marshall <[email protected]>
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@hubcapsc
hubcapsc committed Apr 28, 2021
1 parent acd3d28 commit 0c4b7ca
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Showing 2 changed files with 53 additions and 103 deletions.
34 changes: 6 additions & 28 deletions fs/orangefs/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -248,21 +248,7 @@ ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,
* or it can pointers to struct page's
*/

/*
* When reading, readahead_size will only be zero when
* we're doing O_DIRECT, otherwise we got here from
* orangefs_readpage.
*
* If we got here from orangefs_readpage we want to
* copy either a page or the whole file into the io
* vector, whichever is smaller.
*/
if (readahead_size)
copy_amount =
min(new_op->downcall.resp.io.amt_complete,
(__s64)PAGE_SIZE);
else
copy_amount = new_op->downcall.resp.io.amt_complete;
copy_amount = new_op->downcall.resp.io.amt_complete;

ret = orangefs_bufmap_copy_to_iovec(iter, buffer_index,
copy_amount);
Expand All @@ -283,19 +269,11 @@ ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,

out:
if (buffer_index >= 0) {
if ((readahead_size) && (type == ORANGEFS_IO_READ)) {
/* readpage */
*index_return = buffer_index;
gossip_debug(GOSSIP_FILE_DEBUG,
"%s: hold on to buffer_index :%d:\n",
__func__, buffer_index);
} else {
/* O_DIRECT */
orangefs_bufmap_put(buffer_index);
gossip_debug(GOSSIP_FILE_DEBUG,
"%s(%pU): PUT buffer_index %d\n",
__func__, handle, buffer_index);
}
orangefs_bufmap_put(buffer_index);
gossip_debug(GOSSIP_FILE_DEBUG,
"%s(%pU): PUT buffer_index %d\n",
__func__, handle, buffer_index);
buffer_index = -1;
}
op_release(new_op);
return ret;
Expand Down
122 changes: 47 additions & 75 deletions fs/orangefs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -245,51 +245,75 @@ static int orangefs_writepages(struct address_space *mapping,

static int orangefs_launder_page(struct page *);

static void orangefs_readahead(struct readahead_control *rac)
{
loff_t offset;
struct iov_iter iter;
struct file *file = rac->file;
struct inode *inode = file->f_mapping->host;
struct xarray *i_pages;
struct page *page;
loff_t new_start = readahead_pos(rac);
int ret;
size_t new_len = 0;

loff_t bytes_remaining = inode->i_size - readahead_pos(rac);
loff_t pages_remaining = bytes_remaining / PAGE_SIZE;

if (pages_remaining >= 1024)
new_len = 4194304;
else if (pages_remaining > readahead_count(rac))
new_len = bytes_remaining;

if (new_len)
readahead_expand(rac, new_start, new_len);

offset = readahead_pos(rac);
i_pages = &file->f_mapping->i_pages;

iov_iter_xarray(&iter, READ, i_pages, offset, readahead_length(rac));

/* read in the pages. */
if ((ret = wait_for_direct_io(ORANGEFS_IO_READ, inode,
&offset, &iter, readahead_length(rac),
inode->i_size, NULL, NULL, file)) < 0)
gossip_debug(GOSSIP_FILE_DEBUG,
"%s: wait_for_direct_io failed. \n", __func__);
else
ret = 0;

/* clean up. */
while ((page = readahead_page(rac))) {
page_endio(page, false, ret);
put_page(page);
}
}

static int orangefs_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
struct iov_iter iter;
struct bio_vec bv;
ssize_t ret;
loff_t off; /* offset into this page */
pgoff_t index; /* which page */
struct page *next_page;
char *kaddr;
loff_t read_size;
int buffer_index = -1; /* orangefs shared memory slot */
int slot_index; /* index into slot */
int remaining;

/*
* Get up to this many bytes from Orangefs at a time and try
* to fill them into the page cache at once. Tests with dd made
* this seem like a reasonable static number, if there was
* interest perhaps this number could be made setable through
* sysfs...
*/
read_size = 524288;

if (PageDirty(page))
orangefs_launder_page(page);

off = page_offset(page);
index = off >> PAGE_SHIFT;
bv.bv_page = page;
bv.bv_len = PAGE_SIZE;
bv.bv_offset = 0;
iov_iter_bvec(&iter, READ, &bv, 1, PAGE_SIZE);

ret = wait_for_direct_io(ORANGEFS_IO_READ, inode, &off, &iter,
read_size, inode->i_size, NULL, &buffer_index, file);
remaining = ret;
PAGE_SIZE, inode->i_size, NULL, NULL, file);
/* this will only zero remaining unread portions of the page data */
iov_iter_zero(~0U, &iter);
/* takes care of potential aliasing */
flush_dcache_page(page);
if (ret < 0) {
SetPageError(page);
unlock_page(page);
goto out;
} else {
SetPageUptodate(page);
if (PageError(page))
Expand All @@ -298,60 +322,7 @@ static int orangefs_readpage(struct file *file, struct page *page)
}
/* unlock the page after the ->readpage() routine completes */
unlock_page(page);

if (remaining > PAGE_SIZE) {
slot_index = 0;
while ((remaining - PAGE_SIZE) >= PAGE_SIZE) {
remaining -= PAGE_SIZE;
/*
* It is an optimization to try and fill more than one
* page... by now we've already gotten the single
* page we were after, if stuff doesn't seem to
* be going our way at this point just return
* and hope for the best.
*
* If we look for pages and they're already there is
* one reason to give up, and if they're not there
* and we can't create them is another reason.
*/

index++;
slot_index++;
next_page = find_get_page(inode->i_mapping, index);
if (next_page) {
gossip_debug(GOSSIP_FILE_DEBUG,
"%s: found next page, quitting\n",
__func__);
put_page(next_page);
goto out;
}
next_page = find_or_create_page(inode->i_mapping,
index,
GFP_KERNEL);
/*
* I've never hit this, leave it as a printk for
* now so it will be obvious.
*/
if (!next_page) {
printk("%s: can't create next page, quitting\n",
__func__);
goto out;
}
kaddr = kmap_atomic(next_page);
orangefs_bufmap_page_fill(kaddr,
buffer_index,
slot_index);
kunmap_atomic(kaddr);
SetPageUptodate(next_page);
unlock_page(next_page);
put_page(next_page);
}
}

out:
if (buffer_index != -1)
orangefs_bufmap_put(buffer_index);
return ret;
return ret;
}

static int orangefs_write_begin(struct file *file,
Expand Down Expand Up @@ -660,6 +631,7 @@ static ssize_t orangefs_direct_IO(struct kiocb *iocb,
/** ORANGEFS2 implementation of address space operations */
static const struct address_space_operations orangefs_address_operations = {
.writepage = orangefs_writepage,
.readahead = orangefs_readahead,
.readpage = orangefs_readpage,
.writepages = orangefs_writepages,
.set_page_dirty = __set_page_dirty_nobuffers,
Expand Down

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