[XFS] clean up the xfs_offset_to_map interface Currently we pass a struct
page and a relative offset into that page around, and returns the current
xfs_iomap_t if the block at the specified offset fits into it, or a NULL
pointer otherwise. This patch passed the full 64bit offset into the inode
that all callers have anyway, and changes the return value to a simple
boolean. Also the function gets a more descriptive name: xfs_iomap_valid.
SGI-PV: 947118
SGI-Modid: xfs-linux-melb:xfs-kern:203825a
Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index e998009..b306e25 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -228,29 +228,13 @@
return -error;
}
-/*
- * Finds the corresponding mapping in block @map array of the
- * given @offset within a @page.
- */
-STATIC xfs_iomap_t *
-xfs_offset_to_map(
- struct page *page,
+STATIC inline int
+xfs_iomap_valid(
xfs_iomap_t *iomapp,
- unsigned long offset)
+ loff_t offset)
{
- xfs_off_t full_offset; /* offset from start of file */
-
- ASSERT(offset < PAGE_CACHE_SIZE);
-
- full_offset = page->index; /* NB: using 64bit number */
- full_offset <<= PAGE_CACHE_SHIFT; /* offset from file start */
- full_offset += offset; /* offset from page start */
-
- if (full_offset < iomapp->iomap_offset)
- return NULL;
- if (iomapp->iomap_offset + (iomapp->iomap_bsize -1) >= full_offset)
- return iomapp;
- return NULL;
+ return offset >= iomapp->iomap_offset &&
+ offset < iomapp->iomap_offset + iomapp->iomap_bsize;
}
/*
@@ -461,31 +445,23 @@
STATIC void
xfs_map_at_offset(
- struct page *page,
struct buffer_head *bh,
- unsigned long offset,
+ loff_t offset,
int block_bits,
- xfs_iomap_t *iomapp,
- xfs_ioend_t *ioend)
+ xfs_iomap_t *iomapp)
{
xfs_daddr_t bn;
- xfs_off_t delta;
int sector_shift;
ASSERT(!(iomapp->iomap_flags & IOMAP_HOLE));
ASSERT(!(iomapp->iomap_flags & IOMAP_DELAY));
ASSERT(iomapp->iomap_bn != IOMAP_DADDR_NULL);
- delta = page->index;
- delta <<= PAGE_CACHE_SHIFT;
- delta += offset;
- delta -= iomapp->iomap_offset;
- delta >>= block_bits;
-
sector_shift = block_bits - BBSHIFT;
- bn = iomapp->iomap_bn >> sector_shift;
- bn += delta;
- BUG_ON(!bn && !(iomapp->iomap_flags & IOMAP_REALTIME));
+ bn = (iomapp->iomap_bn >> sector_shift) +
+ ((offset - iomapp->iomap_offset) >> block_bits);
+
+ ASSERT(bn || (iomapp->iomap_flags & IOMAP_REALTIME));
ASSERT((bn << sector_shift) >= iomapp->iomap_bn);
lock_buffer(bh);
@@ -569,8 +545,10 @@
if (tindex == tlast) {
pg_offset =
i_size_read(inode) & (PAGE_CACHE_SIZE - 1);
- if (!pg_offset)
+ if (!pg_offset) {
+ done = 1;
break;
+ }
} else
pg_offset = PAGE_CACHE_SIZE;
@@ -585,6 +563,7 @@
}
total += len;
+ tindex++;
}
pagevec_release(&pvec);
@@ -638,19 +617,19 @@
struct inode *inode,
struct page *page,
loff_t tindex,
- xfs_iomap_t *iomapp,
+ xfs_iomap_t *mp,
xfs_ioend_t **ioendp,
struct writeback_control *wbc,
int startio,
int all_bh)
{
struct buffer_head *bh, *head;
- xfs_iomap_t *mp = iomapp, *tmp;
unsigned long p_offset, end_offset;
unsigned int type;
int bbits = inode->i_blkbits;
int len, page_dirty;
int count = 0, done = 0, uptodate = 1;
+ xfs_off_t f_offset = page_offset(page);
if (page->index != tindex)
goto fail;
@@ -703,15 +682,15 @@
}
continue;
}
- tmp = xfs_offset_to_map(page, mp, p_offset);
- if (!tmp) {
+
+ if (!xfs_iomap_valid(mp, f_offset + p_offset)) {
done = 1;
continue;
}
- ASSERT(!(tmp->iomap_flags & IOMAP_HOLE));
- ASSERT(!(tmp->iomap_flags & IOMAP_DELAY));
+ ASSERT(!(mp->iomap_flags & IOMAP_HOLE));
+ ASSERT(!(mp->iomap_flags & IOMAP_DELAY));
- xfs_map_at_offset(page, bh, p_offset, bbits, tmp, *ioendp);
+ xfs_map_at_offset(bh, f_offset + p_offset, bbits, mp);
if (startio) {
xfs_add_to_ioend(inode, bh, p_offset,
type, ioendp, done);
@@ -805,15 +784,14 @@
int unmapped) /* also implies page uptodate */
{
struct buffer_head *bh, *head;
- xfs_iomap_t *iomp, iomap;
+ xfs_iomap_t iomap;
xfs_ioend_t *ioend = NULL, *iohead = NULL;
loff_t offset;
unsigned long p_offset = 0;
unsigned int type;
__uint64_t end_offset;
pgoff_t end_index, last_index, tlast;
- int flags, len, err, done = 1;
- int uptodate = 1;
+ int flags, len, err, iomap_valid = 0, uptodate = 1;
int page_dirty, count = 0, trylock_flag = 0;
/* wait for other IO threads? */
@@ -854,11 +832,9 @@
p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
page_dirty = p_offset / len;
- iomp = NULL;
bh = head = page_buffers(page);
offset = page_offset(page);
- /* TODO: fix up "done" variable and iomap pointer (boolean) */
/* TODO: cleanup count and page_dirty */
do {
@@ -867,14 +843,16 @@
if (!buffer_uptodate(bh))
uptodate = 0;
if (!(PageUptodate(page) || buffer_uptodate(bh)) && !startio) {
- done = 1;
+ /*
+ * the iomap is actually still valid, but the ioend
+ * isn't. shouldn't happen too often.
+ */
+ iomap_valid = 0;
continue;
}
- if (iomp) {
- iomp = xfs_offset_to_map(page, &iomap, p_offset);
- done = (iomp == NULL);
- }
+ if (iomap_valid)
+ iomap_valid = xfs_iomap_valid(&iomap, offset);
/*
* First case, map an unwritten extent and prepare for
@@ -894,22 +872,20 @@
flags |= trylock_flag;
}
- if (!iomp) {
- done = 1;
+ if (!iomap_valid) {
err = xfs_map_blocks(inode, offset, len, &iomap,
flags);
if (err)
goto error;
- iomp = xfs_offset_to_map(page, &iomap,
- p_offset);
- done = (iomp == NULL);
+ iomap_valid = xfs_iomap_valid(&iomap, offset);
}
- if (iomp) {
- xfs_map_at_offset(page, bh, p_offset,
- inode->i_blkbits, iomp, ioend);
+ if (iomap_valid) {
+ xfs_map_at_offset(bh, offset,
+ inode->i_blkbits, &iomap);
if (startio) {
xfs_add_to_ioend(inode, bh, p_offset,
- type, &ioend, done);
+ type, &ioend,
+ !iomap_valid);
} else {
set_buffer_dirty(bh);
unlock_buffer(bh);
@@ -917,8 +893,6 @@
}
page_dirty--;
count++;
- } else {
- done = 1;
}
} else if ((buffer_uptodate(bh) || PageUptodate(page)) &&
(unmapped || startio)) {
@@ -931,7 +905,7 @@
* was found, and we are in a path where we
* need to write the whole page out.
*/
- if (!iomp) {
+ if (!iomap_valid) {
int size;
size = xfs_probe_unmapped_cluster(
@@ -939,21 +913,19 @@
err = xfs_map_blocks(inode, offset,
size, &iomap,
BMAPI_WRITE|BMAPI_MMAP);
- if (err) {
+ if (err)
goto error;
- }
- iomp = xfs_offset_to_map(page, &iomap,
- p_offset);
- done = (iomp == NULL);
+ iomap_valid = xfs_iomap_valid(&iomap,
+ offset);
}
- if (iomp) {
- xfs_map_at_offset(page, bh, p_offset,
- inode->i_blkbits, iomp,
- ioend);
+ if (iomap_valid) {
+ xfs_map_at_offset(bh, offset,
+ inode->i_blkbits,
+ &iomap);
if (startio) {
xfs_add_to_ioend(inode,
bh, p_offset, type,
- &ioend, done);
+ &ioend, !iomap_valid);
} else {
set_buffer_dirty(bh);
unlock_buffer(bh);
@@ -961,8 +933,6 @@
}
page_dirty--;
count++;
- } else {
- done = 1;
}
} else if (startio) {
if (buffer_uptodate(bh) &&
@@ -970,14 +940,14 @@
ASSERT(buffer_mapped(bh));
xfs_add_to_ioend(inode,
bh, p_offset, type,
- &ioend, done);
+ &ioend, !iomap_valid);
page_dirty--;
count++;
} else {
- done = 1;
+ iomap_valid = 0;
}
} else {
- done = 1;
+ iomap_valid = 0;
}
}
@@ -992,11 +962,11 @@
if (startio)
xfs_start_page_writeback(page, wbc, 1, count);
- if (ioend && iomp && !done) {
- offset = (iomp->iomap_offset + iomp->iomap_bsize - 1) >>
+ if (ioend && iomap_valid) {
+ offset = (iomap.iomap_offset + iomap.iomap_bsize - 1) >>
PAGE_CACHE_SHIFT;
tlast = min_t(pgoff_t, offset, last_index);
- xfs_cluster_write(inode, page->index + 1, iomp, &ioend,
+ xfs_cluster_write(inode, page->index + 1, &iomap, &ioend,
wbc, startio, unmapped, tlast);
}