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author | Jan Kara <jack@suse.cz> | 2016-11-20 17:36:06 -0500 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2016-11-20 17:36:06 -0500 |
commit | 364443cbcfe70f927b6a0dc0d410b4d4318bc1ca (patch) | |
tree | f482d79f1f1d84467a76d8a8cc0197b4e5a02f56 /fs/ext4/inode.c | |
parent | a3caa24b703794507bf2e0a68bdc800b90f5e70b (diff) | |
download | op-kernel-dev-364443cbcfe70f927b6a0dc0d410b4d4318bc1ca.zip op-kernel-dev-364443cbcfe70f927b6a0dc0d410b4d4318bc1ca.tar.gz |
ext4: convert DAX reads to iomap infrastructure
Implement basic iomap_begin function that handles reading and use it for
DAX reads.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r-- | fs/ext4/inode.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 733fda1..5e0526f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -37,6 +37,7 @@ #include <linux/printk.h> #include <linux/slab.h> #include <linux/bitops.h> +#include <linux/iomap.h> #include "ext4_jbd2.h" #include "xattr.h" @@ -3318,6 +3319,59 @@ int ext4_dax_get_block(struct inode *inode, sector_t iblock, clear_buffer_new(bh_result); return 0; } + +static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned flags, struct iomap *iomap) +{ + unsigned int blkbits = inode->i_blkbits; + unsigned long first_block = offset >> blkbits; + unsigned long last_block = (offset + length - 1) >> blkbits; + struct ext4_map_blocks map; + int ret; + + if (flags & IOMAP_WRITE) + return -EIO; + + if (WARN_ON_ONCE(ext4_has_inline_data(inode))) + return -ERANGE; + + map.m_lblk = first_block; + map.m_len = last_block - first_block + 1; + + ret = ext4_map_blocks(NULL, inode, &map, 0); + if (ret < 0) + return ret; + + iomap->flags = 0; + iomap->bdev = inode->i_sb->s_bdev; + iomap->offset = first_block << blkbits; + + if (ret == 0) { + iomap->type = IOMAP_HOLE; + iomap->blkno = IOMAP_NULL_BLOCK; + iomap->length = (u64)map.m_len << blkbits; + } else { + if (map.m_flags & EXT4_MAP_MAPPED) { + iomap->type = IOMAP_MAPPED; + } else if (map.m_flags & EXT4_MAP_UNWRITTEN) { + iomap->type = IOMAP_UNWRITTEN; + } else { + WARN_ON_ONCE(1); + return -EIO; + } + iomap->blkno = (sector_t)map.m_pblk << (blkbits - 9); + iomap->length = (u64)map.m_len << blkbits; + } + + if (map.m_flags & EXT4_MAP_NEW) + iomap->flags |= IOMAP_F_NEW; + return 0; +} + +struct iomap_ops ext4_iomap_ops = { + .iomap_begin = ext4_iomap_begin, +}; + #else /* Just define empty function, it will never get called. */ int ext4_dax_get_block(struct inode *inode, sector_t iblock, |