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Message-ID: <4E82C0D7.1060307@oracle.com>
Date: Wed, 28 Sep 2011 14:38:15 +0800
From: Jeff Liu <jeff.liu@...cle.com>
To: linux-ext4@...r.kernel.org
CC: Yongqiang Yang <xiaoqiangnk@...il.com>,
Sunil Mushran <sunil.mushran@...cle.com>
Subject: [PATCH 1/2 V2] Consolidate delayed-extents fetch procedure to ext4_get_delayed_extent()
Move fetch delayed-extents procedure to a new function ext4_get_delayed_extent(), and modify the
fiemap callback function accordingly.
Signed-off-by: Jie Liu <jeff.liu@...cle.com>
---
fs/ext4/extents.c | 329 ++++++++++++++++++++++++++++-------------------------
1 files changed, 174 insertions(+), 155 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 57cf568..06e88d4 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3901,188 +3901,207 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
}
/*
- * Callback function called for each extent to gather FIEMAP information.
+ * No extent in extent-tree contains block @newex->ec_start,
+ * then the block may stay in 1)a hole or 2)delayed-extent.
+ *
+ * Holes or delayed-extents are processed as follows.
+ * 1. lookup dirty pages with specified range in pagecache.
+ * If no page is got, then there is no delayed-extent and
+ * return with EXT_CONTINUE.
+ * 2. find the 1st mapped buffer,
+ * 3. check if the mapped buffer is both in the request range
+ * and a delayed buffer. If not, there is no delayed-extent,
+ * then return.
+ * 4. a delayed-extent is found, the extent will be collected.
+ * 5. fill the ext_seek_info.offset with logical and return
+ * and EXT_BREAK if a delayed-extent is found.
+ * 6. same as above, but return EXT_BREAK if a hole is found.
*/
-static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next,
- struct ext4_ext_cache *newex, struct ext4_extent *ex,
- void *data)
+static int ext4_get_delayed_extent(struct inode *inode, ext4_lblk_t next,
+ struct ext4_ext_cache *newex,
+ __u64 *logical, __u32 *flags)
{
- __u64 logical;
- __u64 physical;
- __u64 length;
- __u32 flags = 0;
- int ret = 0;
- struct fiemap_extent_info *fieinfo = data;
- unsigned char blksize_bits;
+ int ret;
+ ext4_lblk_t end = 0;
+ pgoff_t last_offset;
+ pgoff_t offset;
+ pgoff_t index;
+ pgoff_t start_index = 0;
+ struct page **pages = NULL;
+ struct buffer_head *bh = NULL;
+ struct buffer_head *head = NULL;
+ unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *);
+ unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
- blksize_bits = inode->i_sb->s_blocksize_bits;
- logical = (__u64)newex->ec_block << blksize_bits;
+ pages = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (pages == NULL)
+ return -ENOMEM;
+
+ offset = *logical >> PAGE_SHIFT;
- if (newex->ec_start == 0) {
- /*
- * No extent in extent-tree contains block @newex->ec_start,
- * then the block may stay in 1)a hole or 2)delayed-extent.
- *
- * Holes or delayed-extents are processed as follows.
- * 1. lookup dirty pages with specified range in pagecache.
- * If no page is got, then there is no delayed-extent and
- * return with EXT_CONTINUE.
- * 2. find the 1st mapped buffer,
- * 3. check if the mapped buffer is both in the request range
- * and a delayed buffer. If not, there is no delayed-extent,
- * then return.
- * 4. a delayed-extent is found, the extent will be collected.
- */
- ext4_lblk_t end = 0;
- pgoff_t last_offset;
- pgoff_t offset;
- pgoff_t index;
- pgoff_t start_index = 0;
- struct page **pages = NULL;
- struct buffer_head *bh = NULL;
- struct buffer_head *head = NULL;
- unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *);
-
- pages = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (pages == NULL)
- return -ENOMEM;
-
- offset = logical >> PAGE_SHIFT;
repeat:
- last_offset = offset;
- head = NULL;
- ret = find_get_pages_tag(inode->i_mapping, &offset,
- PAGECACHE_TAG_DIRTY, nr_pages, pages);
-
- if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
- /* First time, try to find a mapped buffer. */
- if (ret == 0) {
+ last_offset = offset;
+ head = NULL;
+ ret = find_get_pages_tag(inode->i_mapping, &offset,
+ PAGECACHE_TAG_DIRTY, nr_pages, pages);
+
+ if (!(*flags & FIEMAP_EXTENT_DELALLOC)) {
+ /* First time, try to find a mapped buffer. */
+ if (ret == 0) {
out:
- for (index = 0; index < ret; index++)
- page_cache_release(pages[index]);
- /* just a hole. */
- kfree(pages);
- return EXT_CONTINUE;
- }
- index = 0;
+ for (index = 0; index < ret; index++)
+ page_cache_release(pages[index]);
+ /* just a hole. */
+ kfree(pages);
+ return EXT_CONTINUE;
+ }
+ index = 0;
next_page:
- /* Try to find the 1st mapped buffer. */
- end = ((__u64)pages[index]->index << PAGE_SHIFT) >>
- blksize_bits;
- if (!page_has_buffers(pages[index]))
- goto out;
- head = page_buffers(pages[index]);
- if (!head)
+ /* Try to find the 1st mapped buffer. */
+ end = ((__u64)pages[index]->index << PAGE_SHIFT) >>
+ blksize_bits;
+ if (!page_has_buffers(pages[index]))
+ goto out;
+ head = page_buffers(pages[index]);
+ if (!head)
+ goto out;
+
+ index++;
+ bh = head;
+ do {
+ if (end >= newex->ec_block +
+ newex->ec_len)
+ /* The buffer is out of
+ * the request range.
+ */
goto out;
- index++;
- bh = head;
- do {
- if (end >= newex->ec_block +
- newex->ec_len)
- /* The buffer is out of
- * the request range.
- */
- goto out;
+ if (buffer_mapped(bh) &&
+ end >= newex->ec_block) {
+ start_index = index - 1;
+ /* get the 1st mapped buffer. */
+ goto found_mapped_buffer;
+ }
- if (buffer_mapped(bh) &&
- end >= newex->ec_block) {
- start_index = index - 1;
- /* get the 1st mapped buffer. */
- goto found_mapped_buffer;
- }
+ bh = bh->b_this_page;
+ end++;
+ } while (bh != head);
- bh = bh->b_this_page;
- end++;
- } while (bh != head);
-
- /* No mapped buffer in the range found in this page,
- * We need to look up next page.
+ /* No mapped buffer in the range found in this page,
+ * We need to look up next page.
+ */
+ if (index >= ret) {
+ /* There is no page left, but we need to limit
+ * newex->ec_len.
*/
- if (index >= ret) {
- /* There is no page left, but we need to limit
- * newex->ec_len.
- */
- newex->ec_len = end - newex->ec_block;
- goto out;
- }
- goto next_page;
- } else {
- /*Find contiguous delayed buffers. */
- if (ret > 0 && pages[0]->index == last_offset)
- head = page_buffers(pages[0]);
- bh = head;
- index = 1;
- start_index = 0;
+ newex->ec_len = end - newex->ec_block;
+ goto out;
}
+ goto next_page;
+ } else {
+ /*Find contiguous delayed buffers. */
+ if (ret > 0 && pages[0]->index == last_offset)
+ head = page_buffers(pages[0]);
+ bh = head;
+ index = 1;
+ start_index = 0;
+ }
found_mapped_buffer:
- if (bh != NULL && buffer_delay(bh)) {
- /* 1st or contiguous delayed buffer found. */
- if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
- /*
- * 1st delayed buffer found, record
- * the start of extent.
- */
- flags |= FIEMAP_EXTENT_DELALLOC;
- newex->ec_block = end;
- logical = (__u64)end << blksize_bits;
+ if (bh != NULL && buffer_delay(bh)) {
+ /* 1st or contiguous delayed buffer found. */
+ if (!(*flags & FIEMAP_EXTENT_DELALLOC)) {
+ /*
+ * 1st delayed buffer found, record
+ * the start of extent.
+ */
+ *flags |= FIEMAP_EXTENT_DELALLOC;
+ newex->ec_block = end;
+ *logical = (__u64)end << blksize_bits;
+ }
+ /* Find contiguous delayed buffers. */
+ do {
+ if (!buffer_delay(bh))
+ goto found_delayed_extent;
+ bh = bh->b_this_page;
+ end++;
+ } while (bh != head);
+
+ for (; index < ret; index++) {
+ if (!page_has_buffers(pages[index])) {
+ bh = NULL;
+ break;
+ }
+ head = page_buffers(pages[index]);
+ if (!head) {
+ bh = NULL;
+ break;
}
- /* Find contiguous delayed buffers. */
+
+ if (pages[index]->index !=
+ pages[start_index]->index + index
+ - start_index) {
+ /* Blocks are not contiguous. */
+ bh = NULL;
+ break;
+ }
+ bh = head;
do {
if (!buffer_delay(bh))
+ /* Delayed-extent ends. */
goto found_delayed_extent;
bh = bh->b_this_page;
end++;
} while (bh != head);
-
- for (; index < ret; index++) {
- if (!page_has_buffers(pages[index])) {
- bh = NULL;
- break;
- }
- head = page_buffers(pages[index]);
- if (!head) {
- bh = NULL;
- break;
- }
-
- if (pages[index]->index !=
- pages[start_index]->index + index
- - start_index) {
- /* Blocks are not contiguous. */
- bh = NULL;
- break;
- }
- bh = head;
- do {
- if (!buffer_delay(bh))
- /* Delayed-extent ends. */
- goto found_delayed_extent;
- bh = bh->b_this_page;
- end++;
- } while (bh != head);
- }
- } else if (!(flags & FIEMAP_EXTENT_DELALLOC))
- /* a hole found. */
- goto out;
-
-found_delayed_extent:
- newex->ec_len = min(end - newex->ec_block,
- (ext4_lblk_t)EXT_INIT_MAX_LEN);
- if (ret == nr_pages && bh != NULL &&
- newex->ec_len < EXT_INIT_MAX_LEN &&
- buffer_delay(bh)) {
- /* Have not collected an extent and continue. */
- for (index = 0; index < ret; index++)
- page_cache_release(pages[index]);
- goto repeat;
}
+ } else if (!(*flags & FIEMAP_EXTENT_DELALLOC))
+ /* a hole found. */
+ goto out;
+found_delayed_extent:
+ newex->ec_len = min(end - newex->ec_block,
+ (ext4_lblk_t)EXT_INIT_MAX_LEN);
+ if (ret == nr_pages && bh != NULL &&
+ newex->ec_len < EXT_INIT_MAX_LEN &&
+ buffer_delay(bh)) {
+ /* Have not collected an extent and continue. */
for (index = 0; index < ret; index++)
page_cache_release(pages[index]);
- kfree(pages);
+ goto repeat;
+ }
+
+ for (index = 0; index < ret; index++)
+ page_cache_release(pages[index]);
+ kfree(pages);
+
+ return EXT_BREAK;
+}
+
+/*
+ * Callback function called for each extent to gather FIEMAP information.
+ */
+static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next,
+ struct ext4_ext_cache *newex, struct ext4_extent *ex,
+ void *data)
+{
+ __u64 logical;
+ __u64 physical;
+ __u64 length;
+ __u32 flags = 0;
+ int ret = 0;
+ struct fiemap_extent_info *fieinfo = data;
+ unsigned char blksize_bits;
+
+ blksize_bits = inode->i_sb->s_blocksize_bits;
+ logical = (__u64)newex->ec_block << blksize_bits;
+
+ if (newex->ec_start == 0) {
+ ret = ext4_get_delayed_extent(inode, next, newex, &logical,
+ &flags);
+ /* a hole found */
+ if (ret == EXT_CONTINUE)
+ return ret;
}
physical = (__u64)newex->ec_start << blksize_bits;
--
1.7.4.1
--
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