[PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their
own extent locking but for the purposes of dedupe, we want to have both
files locked down across a set of readpage operations (so that we can
compare data). Introduce this variant and a flag which can be set for
extent_read_full_page() to indicate that we are already locked.
Partial credit for this patch goes to Gabriel de Perthuis g2p.c...@gmail.com
as I have included a fix from him to the original patch which avoids a
deadlock on compressed extents.
Signed-off-by: Mark Fasheh mfas...@suse.de
---
fs/btrfs/compression.c | 6 +-
fs/btrfs/extent_io.c | 41 +++--
fs/btrfs/extent_io.h | 3 +++
3 files changed, 39 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 15b9408..05819c3 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -636,7 +636,11 @@ int btrfs_submit_compressed_read(struct inode *inode,
struct bio *bio,
faili = nr_pages - 1;
cb-nr_pages = nr_pages;
- add_ra_bio_pages(inode, em_start + em_len, cb);
+ /* In the parent-locked case, we only locked the range we are
+* interested in. In all other cases, we can opportunistically
+* cache decompressed data that goes beyond the requested range. */
+ if (!(bio_flags EXTENT_BIO_PARENT_LOCKED))
+ add_ra_bio_pages(inode, em_start + em_len, cb);
/* include any pages we added in add_ra-bio_pages */
uncompressed_len = bio-bi_vcnt * PAGE_CACHE_SIZE;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index cdee391..80ce106 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2643,11 +2643,12 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
struct btrfs_ordered_extent *ordered;
int ret;
int nr = 0;
+ int parent_locked = *bio_flags EXTENT_BIO_PARENT_LOCKED;
size_t pg_offset = 0;
size_t iosize;
size_t disk_io_size;
size_t blocksize = inode-i_sb-s_blocksize;
- unsigned long this_bio_flag = 0;
+ unsigned long this_bio_flag = *bio_flags EXTENT_BIO_PARENT_LOCKED;
set_page_extent_mapped(page);
@@ -2659,7 +2660,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
end = page_end;
- while (1) {
+ while (!parent_locked) {
lock_extent(tree, start, end);
ordered = btrfs_lookup_ordered_extent(inode, start);
if (!ordered)
@@ -2695,15 +2696,18 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
kunmap_atomic(userpage);
set_extent_uptodate(tree, cur, cur + iosize - 1,
cached, GFP_NOFS);
- unlock_extent_cached(tree, cur, cur + iosize - 1,
-cached, GFP_NOFS);
+ if (!parent_locked)
+ unlock_extent_cached(tree, cur,
+cur + iosize - 1,
+cached, GFP_NOFS);
break;
}
em = get_extent(inode, page, pg_offset, cur,
end - cur + 1, 0);
if (IS_ERR_OR_NULL(em)) {
SetPageError(page);
- unlock_extent(tree, cur, end);
+ if (!parent_locked)
+ unlock_extent(tree, cur, end);
break;
}
extent_offset = cur - em-start;
@@ -2711,7 +2715,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
BUG_ON(end cur);
if (test_bit(EXTENT_FLAG_COMPRESSED, em-flags)) {
- this_bio_flag = EXTENT_BIO_COMPRESSED;
+ this_bio_flag |= EXTENT_BIO_COMPRESSED;
extent_set_compress_type(this_bio_flag,
em-compress_type);
}
@@ -2755,7 +2759,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
if (test_range_bit(tree, cur, cur_end,
EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2765,7 +2770,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
*/
if (block_start == EXTENT_MAP_INLINE) {
[PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their
own extent locking but for the purposes of dedupe, we want to have both
files locked down across a set of readpage operations (so that we can
compare data). Introduce this variant and a flag which can be set for
extent_read_full_page() to indicate that we are already locked.
Partial credit for this patch goes to Gabriel de Perthuis g2p.c...@gmail.com
as I have included a fix from him to the original patch which avoids a
deadlock on compressed extents.
Signed-off-by: Mark Fasheh mfas...@suse.de
---
fs/btrfs/compression.c | 6 +-
fs/btrfs/extent_io.c | 41 +++--
fs/btrfs/extent_io.h | 3 +++
3 files changed, 39 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 15b9408..05819c3 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -636,7 +636,11 @@ int btrfs_submit_compressed_read(struct inode *inode,
struct bio *bio,
faili = nr_pages - 1;
cb-nr_pages = nr_pages;
- add_ra_bio_pages(inode, em_start + em_len, cb);
+ /* In the parent-locked case, we only locked the range we are
+* interested in. In all other cases, we can opportunistically
+* cache decompressed data that goes beyond the requested range. */
+ if (!(bio_flags EXTENT_BIO_PARENT_LOCKED))
+ add_ra_bio_pages(inode, em_start + em_len, cb);
/* include any pages we added in add_ra-bio_pages */
uncompressed_len = bio-bi_vcnt * PAGE_CACHE_SIZE;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index cdee391..80ce106 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2643,11 +2643,12 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
struct btrfs_ordered_extent *ordered;
int ret;
int nr = 0;
+ int parent_locked = *bio_flags EXTENT_BIO_PARENT_LOCKED;
size_t pg_offset = 0;
size_t iosize;
size_t disk_io_size;
size_t blocksize = inode-i_sb-s_blocksize;
- unsigned long this_bio_flag = 0;
+ unsigned long this_bio_flag = *bio_flags EXTENT_BIO_PARENT_LOCKED;
set_page_extent_mapped(page);
@@ -2659,7 +2660,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
end = page_end;
- while (1) {
+ while (!parent_locked) {
lock_extent(tree, start, end);
ordered = btrfs_lookup_ordered_extent(inode, start);
if (!ordered)
@@ -2695,15 +2696,18 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
kunmap_atomic(userpage);
set_extent_uptodate(tree, cur, cur + iosize - 1,
cached, GFP_NOFS);
- unlock_extent_cached(tree, cur, cur + iosize - 1,
-cached, GFP_NOFS);
+ if (!parent_locked)
+ unlock_extent_cached(tree, cur,
+cur + iosize - 1,
+cached, GFP_NOFS);
break;
}
em = get_extent(inode, page, pg_offset, cur,
end - cur + 1, 0);
if (IS_ERR_OR_NULL(em)) {
SetPageError(page);
- unlock_extent(tree, cur, end);
+ if (!parent_locked)
+ unlock_extent(tree, cur, end);
break;
}
extent_offset = cur - em-start;
@@ -2711,7 +2715,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
BUG_ON(end cur);
if (test_bit(EXTENT_FLAG_COMPRESSED, em-flags)) {
- this_bio_flag = EXTENT_BIO_COMPRESSED;
+ this_bio_flag |= EXTENT_BIO_COMPRESSED;
extent_set_compress_type(this_bio_flag,
em-compress_type);
}
@@ -2755,7 +2759,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
if (test_range_bit(tree, cur, cur_end,
EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2765,7 +2770,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
*/
if (block_start == EXTENT_MAP_INLINE) {
[PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their
own extent locking but for the purposes of dedupe, we want to have both
files locked down across a set of readpage operations (so that we can
compare data). Introduce this variant and a flag which can be set for
extent_read_full_page() to indicate that we are already locked.
Partial credit for this patch goes to Gabriel de Perthuis g2p.c...@gmail.com
as I have included a fix from him to the original patch which avoids a
deadlock on compressed extents.
Signed-off-by: Mark Fasheh mfas...@suse.de
---
fs/btrfs/compression.c | 6 +-
fs/btrfs/extent_io.c | 41 +++--
fs/btrfs/extent_io.h | 3 +++
3 files changed, 39 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 15b9408..05819c3 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -636,7 +636,11 @@ int btrfs_submit_compressed_read(struct inode *inode,
struct bio *bio,
faili = nr_pages - 1;
cb-nr_pages = nr_pages;
- add_ra_bio_pages(inode, em_start + em_len, cb);
+ /* In the parent-locked case, we only locked the range we are
+* interested in. In all other cases, we can opportunistically
+* cache decompressed data that goes beyond the requested range. */
+ if (!(bio_flags EXTENT_BIO_PARENT_LOCKED))
+ add_ra_bio_pages(inode, em_start + em_len, cb);
/* include any pages we added in add_ra-bio_pages */
uncompressed_len = bio-bi_vcnt * PAGE_CACHE_SIZE;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index cdee391..80ce106 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2643,11 +2643,12 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
struct btrfs_ordered_extent *ordered;
int ret;
int nr = 0;
+ int parent_locked = *bio_flags EXTENT_BIO_PARENT_LOCKED;
size_t pg_offset = 0;
size_t iosize;
size_t disk_io_size;
size_t blocksize = inode-i_sb-s_blocksize;
- unsigned long this_bio_flag = 0;
+ unsigned long this_bio_flag = *bio_flags EXTENT_BIO_PARENT_LOCKED;
set_page_extent_mapped(page);
@@ -2659,7 +2660,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
end = page_end;
- while (1) {
+ while (!parent_locked) {
lock_extent(tree, start, end);
ordered = btrfs_lookup_ordered_extent(inode, start);
if (!ordered)
@@ -2695,15 +2696,18 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
kunmap_atomic(userpage);
set_extent_uptodate(tree, cur, cur + iosize - 1,
cached, GFP_NOFS);
- unlock_extent_cached(tree, cur, cur + iosize - 1,
-cached, GFP_NOFS);
+ if (!parent_locked)
+ unlock_extent_cached(tree, cur,
+cur + iosize - 1,
+cached, GFP_NOFS);
break;
}
em = get_extent(inode, page, pg_offset, cur,
end - cur + 1, 0);
if (IS_ERR_OR_NULL(em)) {
SetPageError(page);
- unlock_extent(tree, cur, end);
+ if (!parent_locked)
+ unlock_extent(tree, cur, end);
break;
}
extent_offset = cur - em-start;
@@ -2711,7 +2715,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
BUG_ON(end cur);
if (test_bit(EXTENT_FLAG_COMPRESSED, em-flags)) {
- this_bio_flag = EXTENT_BIO_COMPRESSED;
+ this_bio_flag |= EXTENT_BIO_COMPRESSED;
extent_set_compress_type(this_bio_flag,
em-compress_type);
}
@@ -2755,7 +2759,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
if (test_range_bit(tree, cur, cur_end,
EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2765,7 +2770,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
*/
if (block_start == EXTENT_MAP_INLINE) {
[PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their
own extent locking but for the purposes of dedupe, we want to have both
files locked down across a set of readpage operations (so that we can
compare data). Introduce this variant and a flag which can be set for
extent_read_full_page() to indicate that we are already locked.
Partial credit for this patch goes to Gabriel de Perthuis g2p.c...@gmail.com
as I have included a fix from him to the original patch which avoids a
deadlock on compressed extents.
Signed-off-by: Mark Fasheh mfas...@suse.de
---
fs/btrfs/compression.c | 6 +-
fs/btrfs/extent_io.c | 41 +++--
fs/btrfs/extent_io.h | 3 +++
3 files changed, 39 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 15b9408..05819c3 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -636,7 +636,11 @@ int btrfs_submit_compressed_read(struct inode *inode,
struct bio *bio,
faili = nr_pages - 1;
cb-nr_pages = nr_pages;
- add_ra_bio_pages(inode, em_start + em_len, cb);
+ /* In the parent-locked case, we only locked the range we are
+* interested in. In all other cases, we can opportunistically
+* cache decompressed data that goes beyond the requested range. */
+ if (!(bio_flags EXTENT_BIO_PARENT_LOCKED))
+ add_ra_bio_pages(inode, em_start + em_len, cb);
/* include any pages we added in add_ra-bio_pages */
uncompressed_len = bio-bi_vcnt * PAGE_CACHE_SIZE;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index cdee391..80ce106 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2643,11 +2643,12 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
struct btrfs_ordered_extent *ordered;
int ret;
int nr = 0;
+ int parent_locked = *bio_flags EXTENT_BIO_PARENT_LOCKED;
size_t pg_offset = 0;
size_t iosize;
size_t disk_io_size;
size_t blocksize = inode-i_sb-s_blocksize;
- unsigned long this_bio_flag = 0;
+ unsigned long this_bio_flag = *bio_flags EXTENT_BIO_PARENT_LOCKED;
set_page_extent_mapped(page);
@@ -2659,7 +2660,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
end = page_end;
- while (1) {
+ while (!parent_locked) {
lock_extent(tree, start, end);
ordered = btrfs_lookup_ordered_extent(inode, start);
if (!ordered)
@@ -2695,15 +2696,18 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
kunmap_atomic(userpage);
set_extent_uptodate(tree, cur, cur + iosize - 1,
cached, GFP_NOFS);
- unlock_extent_cached(tree, cur, cur + iosize - 1,
-cached, GFP_NOFS);
+ if (!parent_locked)
+ unlock_extent_cached(tree, cur,
+cur + iosize - 1,
+cached, GFP_NOFS);
break;
}
em = get_extent(inode, page, pg_offset, cur,
end - cur + 1, 0);
if (IS_ERR_OR_NULL(em)) {
SetPageError(page);
- unlock_extent(tree, cur, end);
+ if (!parent_locked)
+ unlock_extent(tree, cur, end);
break;
}
extent_offset = cur - em-start;
@@ -2711,7 +2715,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
BUG_ON(end cur);
if (test_bit(EXTENT_FLAG_COMPRESSED, em-flags)) {
- this_bio_flag = EXTENT_BIO_COMPRESSED;
+ this_bio_flag |= EXTENT_BIO_COMPRESSED;
extent_set_compress_type(this_bio_flag,
em-compress_type);
}
@@ -2755,7 +2759,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
if (test_range_bit(tree, cur, cur_end,
EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2765,7 +2770,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
*/
if (block_start == EXTENT_MAP_INLINE) {
Re: [PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their own extent locking but for the purposes of dedupe, we want to have both files locked down across a set of readpage operations (so that we can compare data). Introduce this variant and a flag which can be set for extent_read_full_page() to indicate that we are already locked. This one can get stuck in TASK_UNINTERRUPTIBLE: [32129.522257] SysRq : Show Blocked State [32129.524337] taskPC stack pid father [32129.526515] python D 88021f394280 0 16281 1 0x0004 [32129.528656] 88020e079a48 0082 88013d3cdd40 88020e079fd8 [32129.530840] 88020e079fd8 88020e079fd8 8802138dc5f0 88013d3cdd40 [32129.533044] 1fff 88015286f440 0008 [32129.535285] Call Trace: [32129.537522] [816dcca9] schedule+0x29/0x70 [32129.539829] [a02b4908] wait_extent_bit+0xf8/0x150 [btrfs] [32129.542130] [8107ea00] ? finish_wait+0x80/0x80 [32129.544463] [a02b4f84] lock_extent_bits+0x44/0xa0 [btrfs] [32129.546824] [a02b4ff3] lock_extent+0x13/0x20 [btrfs] [32129.549198] [a02dc0cf] add_ra_bio_pages.isra.8+0x17f/0x2d0 [btrfs] [32129.551602] [a02dccfc] btrfs_submit_compressed_read+0x25c/0x4c0 [btrfs] [32129.554028] [a029d131] btrfs_submit_bio_hook+0x1d1/0x1e0 [btrfs] [32129.556457] [a02b2d07] submit_one_bio+0x67/0xa0 [btrfs] [32129.558899] [a02b7ecd] extent_read_full_page_nolock+0x4d/0x60 [btrfs] [32129.561290] [a02c8052] fill_data+0xb2/0x230 [btrfs] [32129.563623] [a02cd57e] btrfs_ioctl+0x1f7e/0x2560 [btrfs] [32129.565924] [816ddbae] ? _raw_spin_lock+0xe/0x20 [32129.568207] [8119b907] ? inode_get_bytes+0x47/0x60 [32129.570472] [811a8297] do_vfs_ioctl+0x97/0x560 [32129.572700] [8119bb5a] ? sys_newfstat+0x2a/0x40 [32129.574882] [811a87f1] sys_ioctl+0x91/0xb0 [32129.577008] [816e64dd] system_call_fastpath+0x1a/0x1f For anyone trying those patches, there's a fix here: https://github.com/g2p/linux/tree/v3.9%2Bbtrfs-extent-same -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their own extent locking but for the purposes of dedupe, we want to have both files locked down across a set of readpage operations (so that we can compare data). Introduce this variant and a flag which can be set for extent_read_full_page() to indicate that we are already locked. This one can get stuck in TASK_UNINTERRUPTIBLE: [32129.522257] SysRq : Show Blocked State [32129.524337] taskPC stack pid father [32129.526515] python D 88021f394280 0 16281 1 0x0004 [32129.528656] 88020e079a48 0082 88013d3cdd40 88020e079fd8 [32129.530840] 88020e079fd8 88020e079fd8 8802138dc5f0 88013d3cdd40 [32129.533044] 1fff 88015286f440 0008 [32129.535285] Call Trace: [32129.537522] [816dcca9] schedule+0x29/0x70 [32129.539829] [a02b4908] wait_extent_bit+0xf8/0x150 [btrfs] [32129.542130] [8107ea00] ? finish_wait+0x80/0x80 [32129.544463] [a02b4f84] lock_extent_bits+0x44/0xa0 [btrfs] [32129.546824] [a02b4ff3] lock_extent+0x13/0x20 [btrfs] [32129.549198] [a02dc0cf] add_ra_bio_pages.isra.8+0x17f/0x2d0 [btrfs] [32129.551602] [a02dccfc] btrfs_submit_compressed_read+0x25c/0x4c0 [btrfs] [32129.554028] [a029d131] btrfs_submit_bio_hook+0x1d1/0x1e0 [btrfs] [32129.556457] [a02b2d07] submit_one_bio+0x67/0xa0 [btrfs] [32129.558899] [a02b7ecd] extent_read_full_page_nolock+0x4d/0x60 [btrfs] [32129.561290] [a02c8052] fill_data+0xb2/0x230 [btrfs] [32129.563623] [a02cd57e] btrfs_ioctl+0x1f7e/0x2560 [btrfs] [32129.565924] [816ddbae] ? _raw_spin_lock+0xe/0x20 [32129.568207] [8119b907] ? inode_get_bytes+0x47/0x60 [32129.570472] [811a8297] do_vfs_ioctl+0x97/0x560 [32129.572700] [8119bb5a] ? sys_newfstat+0x2a/0x40 [32129.574882] [811a87f1] sys_ioctl+0x91/0xb0 [32129.577008] [816e64dd] system_call_fastpath+0x1a/0x1f Side note, I wish btrfs used TASK_KILLABLE[1] instead. [1]: https://lwn.net/Articles/288056/ -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
On Tue, Apr 16, 2013 at 03:15:34PM -0700, Mark Fasheh wrote:
@@ -2625,7 +2625,7 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
}
end = page_end;
- while (1) {
+ while (1 !parent_locked) {
the patch is ok, just this caught my eye :)
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[PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock()
We want this for btrfs_extent_same. Basically readpage and friends do their
own extent locking but for the purposes of dedupe, we want to have both
files locked down across a set of readpage operations (so that we can
compare data). Introduce this variant and a flag which can be set for
extent_read_full_page() to indicate that we are already locked.
Signed-off-by: Mark Fasheh mfas...@suse.de
---
fs/btrfs/extent_io.c | 44
fs/btrfs/extent_io.h |2 ++
2 files changed, 34 insertions(+), 12 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 1b319df..9256503 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2592,7 +2592,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
struct page *page,
get_extent_t *get_extent,
struct bio **bio, int mirror_num,
- unsigned long *bio_flags)
+ unsigned long *bio_flags, int parent_locked)
{
struct inode *inode = page-mapping-host;
u64 start = (u64)page-index PAGE_CACHE_SHIFT;
@@ -2625,7 +2625,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
end = page_end;
- while (1) {
+ while (1 !parent_locked) {
lock_extent(tree, start, end);
ordered = btrfs_lookup_ordered_extent(inode, start);
if (!ordered)
@@ -2659,15 +2659,18 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
kunmap_atomic(userpage);
set_extent_uptodate(tree, cur, cur + iosize - 1,
cached, GFP_NOFS);
- unlock_extent_cached(tree, cur, cur + iosize - 1,
-cached, GFP_NOFS);
+ if (!parent_locked)
+ unlock_extent_cached(tree, cur,
+cur + iosize - 1,
+cached, GFP_NOFS);
break;
}
em = get_extent(inode, page, pg_offset, cur,
end - cur + 1, 0);
if (IS_ERR_OR_NULL(em)) {
SetPageError(page);
- unlock_extent(tree, cur, end);
+ if (!parent_locked)
+ unlock_extent(tree, cur, end);
break;
}
extent_offset = cur - em-start;
@@ -2719,7 +2722,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
if (test_range_bit(tree, cur, cur_end,
EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2729,7 +2733,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
*/
if (block_start == EXTENT_MAP_INLINE) {
SetPageError(page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -2756,7 +2761,8 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
if (ret) {
SetPageError(page);
- unlock_extent(tree, cur, cur + iosize - 1);
+ if (!parent_locked)
+ unlock_extent(tree, cur, cur + iosize - 1);
}
cur = cur + iosize;
pg_offset += iosize;
@@ -2778,7 +2784,21 @@ int extent_read_full_page(struct extent_io_tree *tree,
struct page *page,
int ret;
ret = __extent_read_full_page(tree, page, get_extent, bio, mirror_num,
- bio_flags);
+ bio_flags, 0);
+ if (bio)
+ ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
+ return ret;
+}
+
+int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page
*page,
+get_extent_t *get_extent, int mirror_num)
+{
+ struct bio *bio = NULL;
+ unsigned long bio_flags = 0;
+ int ret;
+
+ ret = __extent_read_full_page(tree, page, get_extent, bio,
