| Message ID | 1406625850-32168-3-git-send-email-miaox@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, Jul 29, 2014 at 10:24 AM, Miao Xie <miaox@cn.fujitsu.com> wrote: > The current code would load checksum data for several times when we split > a whole direct read io because of the limit of the raid stripe, it would > make us search the csum tree for several times. In fact, it just wasted time, > and made the contention of the csum tree root be more serious. This patch > improves this problem by loading the data at once. > > Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> > --- > Changelog v1 -> v2: > - Remove the __GFP_ZERO flag in btrfs_submit_direct because it would trigger > a WARNing. It is reported by Filipe David Manana, Thanks. Hi Miao, Without this flag (to zero the struct), I get a general protection fault at: (gdb) list *(btrfs_endio_direct_read+0xb8) 0x38378 is in btrfs_endio_direct_read (fs/btrfs/inode.c:7242). 7237 if (err) 7238 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7239 dio_end_io(dio_bio, err); 7240 7241 if (io_bio->end_io) 7242 io_bio->end_io(io_bio, err); 7243 bio_put(bio); 7244 } Happens when running xfstests/generic/091 > --- > fs/btrfs/btrfs_inode.h | 1 - > fs/btrfs/ctree.h | 3 +-- > fs/btrfs/extent_io.c | 13 +++++++++++-- > fs/btrfs/file-item.c | 14 ++------------ > fs/btrfs/inode.c | 38 +++++++++++++++++++++----------------- > 5 files changed, 35 insertions(+), 34 deletions(-) > > diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h > index a0cf3e5..b69bf7e 100644 > --- a/fs/btrfs/btrfs_inode.h > +++ b/fs/btrfs/btrfs_inode.h > @@ -263,7 +263,6 @@ struct btrfs_dio_private { > > /* dio_bio came from fs/direct-io.c */ > struct bio *dio_bio; > - u8 csum[0]; > }; > > /* > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index be91397..40e9938 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -3739,8 +3739,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans, > int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, > struct bio *bio, u32 *dst); > int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode, > - struct btrfs_dio_private *dip, struct bio *bio, > - u64 logical_offset); > + struct bio *bio, u64 logical_offset); > int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, > struct btrfs_root *root, > u64 objectid, u64 pos, > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 23398ad..0fb63c4 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -2617,9 +2617,18 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, > > struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) > { > - return bio_clone_bioset(bio, gfp_mask, btrfs_bioset); > -} > + struct btrfs_io_bio *btrfs_bio; > + struct bio *new; > > + new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset); > + if (new) { > + btrfs_bio = btrfs_io_bio(new); > + btrfs_bio->csum = NULL; > + btrfs_bio->csum_allocated = NULL; > + btrfs_bio->end_io = NULL; > + } > + return bio; > +} > > /* this also allocates from the btrfs_bioset */ > struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c > index f46cfe4..cf1b94f 100644 > --- a/fs/btrfs/file-item.c > +++ b/fs/btrfs/file-item.c > @@ -299,19 +299,9 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, > } > > int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode, > - struct btrfs_dio_private *dip, struct bio *bio, > - u64 offset) > + struct bio *bio, u64 offset) > { > - int len = (bio->bi_iter.bi_sector << 9) - dip->disk_bytenr; > - u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); > - int ret; > - > - len >>= inode->i_sb->s_blocksize_bits; > - len *= csum_size; > - > - ret = __btrfs_lookup_bio_sums(root, inode, bio, offset, > - (u32 *)(dip->csum + len), 1); > - return ret; > + return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1); > } > > int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 548489e..fd88126 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -7081,7 +7081,8 @@ static void btrfs_endio_direct_read(struct bio *bio, int err) > struct inode *inode = dip->inode; > struct btrfs_root *root = BTRFS_I(inode)->root; > struct bio *dio_bio; > - u32 *csums = (u32 *)dip->csum; > + struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); > + u32 *csums = (u32 *)io_bio->csum; > u64 start; > int i; > > @@ -7123,6 +7124,9 @@ static void btrfs_endio_direct_read(struct bio *bio, int err) > if (err) > clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); > dio_end_io(dio_bio, err); > + > + if (io_bio->end_io) > + io_bio->end_io(io_bio, err); > bio_put(bio); > } > > @@ -7261,13 +7265,20 @@ static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, > ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); > if (ret) > goto err; > - } else if (!skip_sum) { > - ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio, > + } else { > + /* > + * We have loaded all the csum data we need when we submit > + * the first bio, so skip it. > + */ > + if (dip->logical_offset != file_offset) > + goto map; > + > + /* Load all csum data at once. */ > + ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, > file_offset); > if (ret) > goto err; > } > - > map: > ret = btrfs_map_bio(root, rw, bio, 0, async_submit); > err: > @@ -7288,7 +7299,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, > u64 submit_len = 0; > u64 map_length; > int nr_pages = 0; > - int ret = 0; > + int ret; > int async_submit = 0; > > map_length = orig_bio->bi_iter.bi_size; > @@ -7392,11 +7403,10 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, > struct btrfs_root *root = BTRFS_I(inode)->root; > struct btrfs_dio_private *dip; > struct bio *io_bio; > + struct btrfs_io_bio *btrfs_bio; > int skip_sum; > - int sum_len; > int write = rw & REQ_WRITE; > int ret = 0; > - u16 csum_size; > > skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; > > @@ -7406,16 +7416,7 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, > goto free_ordered; > } > > - if (!skip_sum && !write) { > - csum_size = btrfs_super_csum_size(root->fs_info->super_copy); > - sum_len = dio_bio->bi_iter.bi_size >> > - inode->i_sb->s_blocksize_bits; > - sum_len *= csum_size; > - } else { > - sum_len = 0; > - } > - > - dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS); > + dip = kmalloc(sizeof(*dip), GFP_NOFS); > if (!dip) { > ret = -ENOMEM; > goto free_io_bio; > @@ -7441,6 +7442,9 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, > if (!ret) > return; > > + btrfs_bio = btrfs_io_bio(io_bio); > + if (btrfs_bio->end_io) > + btrfs_bio->end_io(btrfs_bio, ret); > free_io_bio: > bio_put(io_bio); > > -- > 1.9.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 8 Aug 2014 01:32:00 +0100, Filipe David Manana wrote: > On Tue, Jul 29, 2014 at 10:24 AM, Miao Xie <miaox@cn.fujitsu.com> wrote: >> The current code would load checksum data for several times when we split >> a whole direct read io because of the limit of the raid stripe, it would >> make us search the csum tree for several times. In fact, it just wasted time, >> and made the contention of the csum tree root be more serious. This patch >> improves this problem by loading the data at once. >> >> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> >> --- >> Changelog v1 -> v2: >> - Remove the __GFP_ZERO flag in btrfs_submit_direct because it would trigger >> a WARNing. It is reported by Filipe David Manana, Thanks. > > Hi Miao, > > Without this flag (to zero the struct), I get a general protection fault at: > > (gdb) list *(btrfs_endio_direct_read+0xb8) > 0x38378 is in btrfs_endio_direct_read (fs/btrfs/inode.c:7242). > 7237 if (err) > 7238 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); > 7239 dio_end_io(dio_bio, err); > 7240 > 7241 if (io_bio->end_io) > 7242 io_bio->end_io(io_bio, err); > 7243 bio_put(bio); > 7244 } > > Happens when running xfstests/generic/091 Sorry, I sent out wrong version of this patchset, which has a bug in btrfs_bio_clone. I will send new version of this patch. The other patches are not changed, and can be applied successfully after the new version of this patch, so don't send them again. Surely, we also can pull the whole patchset from https://github.com/miaoxie/linux-btrfs.git for-Chris Thanks Miao > > >> --- >> fs/btrfs/btrfs_inode.h | 1 - >> fs/btrfs/ctree.h | 3 +-- >> fs/btrfs/extent_io.c | 13 +++++++++++-- >> fs/btrfs/file-item.c | 14 ++------------ >> fs/btrfs/inode.c | 38 +++++++++++++++++++++----------------- >> 5 files changed, 35 insertions(+), 34 deletions(-) >> >> diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h >> index a0cf3e5..b69bf7e 100644 >> --- a/fs/btrfs/btrfs_inode.h >> +++ b/fs/btrfs/btrfs_inode.h >> @@ -263,7 +263,6 @@ struct btrfs_dio_private { >> >> /* dio_bio came from fs/direct-io.c */ >> struct bio *dio_bio; >> - u8 csum[0]; >> }; >> >> /* >> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h >> index be91397..40e9938 100644 >> --- a/fs/btrfs/ctree.h >> +++ b/fs/btrfs/ctree.h >> @@ -3739,8 +3739,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans, >> int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, >> struct bio *bio, u32 *dst); >> int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode, >> - struct btrfs_dio_private *dip, struct bio *bio, >> - u64 logical_offset); >> + struct bio *bio, u64 logical_offset); >> int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, >> struct btrfs_root *root, >> u64 objectid, u64 pos, >> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c >> index 23398ad..0fb63c4 100644 >> --- a/fs/btrfs/extent_io.c >> +++ b/fs/btrfs/extent_io.c >> @@ -2617,9 +2617,18 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, >> >> struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) >> { >> - return bio_clone_bioset(bio, gfp_mask, btrfs_bioset); >> -} >> + struct btrfs_io_bio *btrfs_bio; >> + struct bio *new; >> >> + new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset); >> + if (new) { >> + btrfs_bio = btrfs_io_bio(new); >> + btrfs_bio->csum = NULL; >> + btrfs_bio->csum_allocated = NULL; >> + btrfs_bio->end_io = NULL; >> + } >> + return bio; >> +} >> >> /* this also allocates from the btrfs_bioset */ >> struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) >> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c >> index f46cfe4..cf1b94f 100644 >> --- a/fs/btrfs/file-item.c >> +++ b/fs/btrfs/file-item.c >> @@ -299,19 +299,9 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, >> } >> >> int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode, >> - struct btrfs_dio_private *dip, struct bio *bio, >> - u64 offset) >> + struct bio *bio, u64 offset) >> { >> - int len = (bio->bi_iter.bi_sector << 9) - dip->disk_bytenr; >> - u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); >> - int ret; >> - >> - len >>= inode->i_sb->s_blocksize_bits; >> - len *= csum_size; >> - >> - ret = __btrfs_lookup_bio_sums(root, inode, bio, offset, >> - (u32 *)(dip->csum + len), 1); >> - return ret; >> + return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1); >> } >> >> int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, >> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c >> index 548489e..fd88126 100644 >> --- a/fs/btrfs/inode.c >> +++ b/fs/btrfs/inode.c >> @@ -7081,7 +7081,8 @@ static void btrfs_endio_direct_read(struct bio *bio, int err) >> struct inode *inode = dip->inode; >> struct btrfs_root *root = BTRFS_I(inode)->root; >> struct bio *dio_bio; >> - u32 *csums = (u32 *)dip->csum; >> + struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); >> + u32 *csums = (u32 *)io_bio->csum; >> u64 start; >> int i; >> >> @@ -7123,6 +7124,9 @@ static void btrfs_endio_direct_read(struct bio *bio, int err) >> if (err) >> clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); >> dio_end_io(dio_bio, err); >> + >> + if (io_bio->end_io) >> + io_bio->end_io(io_bio, err); >> bio_put(bio); >> } >> >> @@ -7261,13 +7265,20 @@ static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, >> ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); >> if (ret) >> goto err; >> - } else if (!skip_sum) { >> - ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio, >> + } else { >> + /* >> + * We have loaded all the csum data we need when we submit >> + * the first bio, so skip it. >> + */ >> + if (dip->logical_offset != file_offset) >> + goto map; >> + >> + /* Load all csum data at once. */ >> + ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, >> file_offset); >> if (ret) >> goto err; >> } >> - >> map: >> ret = btrfs_map_bio(root, rw, bio, 0, async_submit); >> err: >> @@ -7288,7 +7299,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, >> u64 submit_len = 0; >> u64 map_length; >> int nr_pages = 0; >> - int ret = 0; >> + int ret; >> int async_submit = 0; >> >> map_length = orig_bio->bi_iter.bi_size; >> @@ -7392,11 +7403,10 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, >> struct btrfs_root *root = BTRFS_I(inode)->root; >> struct btrfs_dio_private *dip; >> struct bio *io_bio; >> + struct btrfs_io_bio *btrfs_bio; >> int skip_sum; >> - int sum_len; >> int write = rw & REQ_WRITE; >> int ret = 0; >> - u16 csum_size; >> >> skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; >> >> @@ -7406,16 +7416,7 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, >> goto free_ordered; >> } >> >> - if (!skip_sum && !write) { >> - csum_size = btrfs_super_csum_size(root->fs_info->super_copy); >> - sum_len = dio_bio->bi_iter.bi_size >> >> - inode->i_sb->s_blocksize_bits; >> - sum_len *= csum_size; >> - } else { >> - sum_len = 0; >> - } >> - >> - dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS); >> + dip = kmalloc(sizeof(*dip), GFP_NOFS); >> if (!dip) { >> ret = -ENOMEM; >> goto free_io_bio; >> @@ -7441,6 +7442,9 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, >> if (!ret) >> return; >> >> + btrfs_bio = btrfs_io_bio(io_bio); >> + if (btrfs_bio->end_io) >> + btrfs_bio->end_io(btrfs_bio, ret); >> free_io_bio: >> bio_put(io_bio); >> >> -- >> 1.9.3 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index a0cf3e5..b69bf7e 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -263,7 +263,6 @@ struct btrfs_dio_private { /* dio_bio came from fs/direct-io.c */ struct bio *dio_bio; - u8 csum[0]; }; /* diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index be91397..40e9938 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3739,8 +3739,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans, int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, struct bio *bio, u32 *dst); int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode, - struct btrfs_dio_private *dip, struct bio *bio, - u64 logical_offset); + struct bio *bio, u64 logical_offset); int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 pos, diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 23398ad..0fb63c4 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2617,9 +2617,18 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) { - return bio_clone_bioset(bio, gfp_mask, btrfs_bioset); -} + struct btrfs_io_bio *btrfs_bio; + struct bio *new; + new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset); + if (new) { + btrfs_bio = btrfs_io_bio(new); + btrfs_bio->csum = NULL; + btrfs_bio->csum_allocated = NULL; + btrfs_bio->end_io = NULL; + } + return bio; +} /* this also allocates from the btrfs_bioset */ struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index f46cfe4..cf1b94f 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -299,19 +299,9 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, } int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode, - struct btrfs_dio_private *dip, struct bio *bio, - u64 offset) + struct bio *bio, u64 offset) { - int len = (bio->bi_iter.bi_sector << 9) - dip->disk_bytenr; - u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); - int ret; - - len >>= inode->i_sb->s_blocksize_bits; - len *= csum_size; - - ret = __btrfs_lookup_bio_sums(root, inode, bio, offset, - (u32 *)(dip->csum + len), 1); - return ret; + return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1); } int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 548489e..fd88126 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7081,7 +7081,8 @@ static void btrfs_endio_direct_read(struct bio *bio, int err) struct inode *inode = dip->inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct bio *dio_bio; - u32 *csums = (u32 *)dip->csum; + struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); + u32 *csums = (u32 *)io_bio->csum; u64 start; int i; @@ -7123,6 +7124,9 @@ static void btrfs_endio_direct_read(struct bio *bio, int err) if (err) clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); dio_end_io(dio_bio, err); + + if (io_bio->end_io) + io_bio->end_io(io_bio, err); bio_put(bio); } @@ -7261,13 +7265,20 @@ static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); if (ret) goto err; - } else if (!skip_sum) { - ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio, + } else { + /* + * We have loaded all the csum data we need when we submit + * the first bio, so skip it. + */ + if (dip->logical_offset != file_offset) + goto map; + + /* Load all csum data at once. */ + ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, file_offset); if (ret) goto err; } - map: ret = btrfs_map_bio(root, rw, bio, 0, async_submit); err: @@ -7288,7 +7299,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, u64 submit_len = 0; u64 map_length; int nr_pages = 0; - int ret = 0; + int ret; int async_submit = 0; map_length = orig_bio->bi_iter.bi_size; @@ -7392,11 +7403,10 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_dio_private *dip; struct bio *io_bio; + struct btrfs_io_bio *btrfs_bio; int skip_sum; - int sum_len; int write = rw & REQ_WRITE; int ret = 0; - u16 csum_size; skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; @@ -7406,16 +7416,7 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, goto free_ordered; } - if (!skip_sum && !write) { - csum_size = btrfs_super_csum_size(root->fs_info->super_copy); - sum_len = dio_bio->bi_iter.bi_size >> - inode->i_sb->s_blocksize_bits; - sum_len *= csum_size; - } else { - sum_len = 0; - } - - dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS); + dip = kmalloc(sizeof(*dip), GFP_NOFS); if (!dip) { ret = -ENOMEM; goto free_io_bio; @@ -7441,6 +7442,9 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio, if (!ret) return; + btrfs_bio = btrfs_io_bio(io_bio); + if (btrfs_bio->end_io) + btrfs_bio->end_io(btrfs_bio, ret); free_io_bio: bio_put(io_bio);
The current code would load checksum data for several times when we split a whole direct read io because of the limit of the raid stripe, it would make us search the csum tree for several times. In fact, it just wasted time, and made the contention of the csum tree root be more serious. This patch improves this problem by loading the data at once. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> --- Changelog v1 -> v2: - Remove the __GFP_ZERO flag in btrfs_submit_direct because it would trigger a WARNing. It is reported by Filipe David Manana, Thanks. --- fs/btrfs/btrfs_inode.h | 1 - fs/btrfs/ctree.h | 3 +-- fs/btrfs/extent_io.c | 13 +++++++++++-- fs/btrfs/file-item.c | 14 ++------------ fs/btrfs/inode.c | 38 +++++++++++++++++++++----------------- 5 files changed, 35 insertions(+), 34 deletions(-)