From: Zhang Yi Replace the single bool did_zero output of ext4_zero_partial_blocks() with a bitmask that records which edge (start, end, or both in the single-block case) was actually partial-zeroed. This allows callers to distinguish which edges have been zeroed, preparing for unaligned FALLOC_FL_WRITE_ZEROES handling in later patches. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara --- fs/ext4/ext4.h | 5 ++++- fs/ext4/extents.c | 2 +- fs/ext4/inode.c | 36 ++++++++++++++++++++++++++++++------ 3 files changed, 35 insertions(+), 8 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 94283a991e5c..b2e55876d0e3 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -3099,8 +3099,11 @@ extern int ext4_chunk_trans_extent(struct inode *inode, int nrblocks); extern int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents); extern int ext4_block_zero_eof(struct inode *inode, loff_t from, loff_t end); + +#define EXT4_PARTIAL_ZERO_START 0x1 +#define EXT4_PARTIAL_ZERO_END 0x2 extern int ext4_zero_partial_blocks(struct inode *inode, loff_t lstart, - loff_t length, bool *did_zero); + loff_t length, unsigned int *partial_zeroed); extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf); extern qsize_t *ext4_get_reserved_space(struct inode *inode); extern int ext4_get_projid(struct inode *inode, kprojid_t *projid); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 27ca641e701b..7a8f9f188a29 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4715,7 +4715,7 @@ static long ext4_zero_range(struct file *file, loff_t offset, loff_t align_start, align_end, new_size = 0; loff_t end = offset + len; unsigned int blocksize = i_blocksize(inode); - bool partial_zeroed = false; + unsigned int partial_zeroed = 0; int ret, flags; trace_ext4_zero_range(inode, offset, len, mode); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 2cb1b93d3ed1..c0c921400aa4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4266,13 +4266,26 @@ int ext4_block_zero_eof(struct inode *inode, loff_t from, loff_t end) return 0; } +/* + * Zero out the unaligned head and tail of the [lstart, lstart+length) + * range. + * + * On return, @partial_zeroed records which edges actually got + * partial-zeroed. Set EXT4_PARTIAL_ZERO_START/EXT4_PARTIAL_ZERO_END if + * the head/tail block got actually partially zeroed (in written, dirty + * unwritten or delalloc state). Cleared if the head/tail block is a + * hole or a clean unwritten block, in which case there is nothing that + * needs zeroing. When the head and tail land in the same block, both + * bits are set together on a successful zeroing. + */ int ext4_zero_partial_blocks(struct inode *inode, loff_t lstart, loff_t length, - bool *did_zero) + unsigned int *partial_zeroed) { struct super_block *sb = inode->i_sb; unsigned partial_start, partial_end; ext4_fsblk_t start, end; loff_t byte_end = (lstart + length - 1); + bool did_zero = false; int err = 0; partial_start = lstart & (sb->s_blocksize - 1); @@ -4284,21 +4297,32 @@ int ext4_zero_partial_blocks(struct inode *inode, loff_t lstart, loff_t length, /* Handle partial zero within the single block */ if (start == end && (partial_start || (partial_end != sb->s_blocksize - 1))) { - err = ext4_block_zero_range(inode, lstart, length, did_zero, + err = ext4_block_zero_range(inode, lstart, length, &did_zero, NULL); + if (did_zero) + *partial_zeroed |= (EXT4_PARTIAL_ZERO_START | + EXT4_PARTIAL_ZERO_END); return err; } /* Handle partial zero out on the start of the range */ if (partial_start) { err = ext4_block_zero_range(inode, lstart, sb->s_blocksize, - did_zero, NULL); + &did_zero, NULL); if (err) return err; + if (did_zero) + *partial_zeroed |= EXT4_PARTIAL_ZERO_START; } /* Handle partial zero out on the end of the range */ - if (partial_end != sb->s_blocksize - 1) + if (partial_end != sb->s_blocksize - 1) { + did_zero = false; err = ext4_block_zero_range(inode, byte_end - partial_end, - partial_end + 1, did_zero, NULL); + partial_end + 1, &did_zero, NULL); + if (err) + return err; + if (did_zero) + *partial_zeroed |= EXT4_PARTIAL_ZERO_END; + } return err; } @@ -4447,7 +4471,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) loff_t end = offset + length; handle_t *handle; unsigned int credits; - bool partial_zeroed = false; + unsigned int partial_zeroed = 0; int ret; trace_ext4_punch_hole(inode, offset, length, 0); -- 2.52.0