| Message ID | 80f6c773a80a731c5c1f5e4d8ebb75d6da58a587.1571647179.git.mbobrowski@mbobrowski.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ext4: port direct I/O to iomap infrastructure | expand |
On Mon 21-10-19 20:18:00, Matthew Bobrowski wrote: > In preparation for porting across the ext4 direct I/O path for reads > and writes over to the iomap infrastructure, split up the IOMAP_WRITE > chunk of code into a separate helper ext4_alloc_iomap(). This way, > when we add the necessary bits for direct I/O, we don't end up with > ext4_iomap_begin() becoming a behemoth twisty maze. > > Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/inode.c | 112 ++++++++++++++++++++++++++---------------------- > 1 file changed, 60 insertions(+), 52 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 0dd29ae5cc8c..3dc92bd8a944 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3442,6 +3442,62 @@ static void ext4_set_iomap(struct inode *inode, struct iomap *iomap, > } > } > > +static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map, > + unsigned int flags) > +{ > + handle_t *handle; > + u8 blkbits = inode->i_blkbits; > + int ret, dio_credits, retries = 0; > + > + /* > + * Trim the mapping request to the maximum value that we can map at > + * once for direct I/O. > + */ > + if (map->m_len > DIO_MAX_BLOCKS) > + map->m_len = DIO_MAX_BLOCKS; > + dio_credits = ext4_chunk_trans_blocks(inode, map->m_len); > + > +retry: > + /* > + * Either we allocate blocks and then don't get an unwritten extent, so > + * in that case we have reserved enough credits. Or, the blocks are > + * already allocated and and unwritten. In that case, the extent > + * conversion fits into the credits too. > + */ > + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); > + if (IS_ERR(handle)) > + return PTR_ERR(handle); > + > + ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO); > + if (ret < 0) > + goto journal_stop; > + > + /* > + * If we have allocated blocks beyond EOF, we need to ensure that > + * they're truncated if we crash before updating the inode size > + * metadata within ext4_iomap_end(). For faults, we don't need to do > + * that (and cannot due to the orphan list operations needing an > + * inode_lock()). If we happen to instantiate blocks beyond EOF, it is > + * because we race with a truncate operation, which already has added > + * the inode onto the orphan list. > + */ > + if (!(flags & IOMAP_FAULT) && map->m_lblk + map->m_len > > + (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { > + int err; > + > + err = ext4_orphan_add(handle, inode); > + if (err < 0) > + ret = err; > + } > + > +journal_stop: > + ext4_journal_stop(handle); > + if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) > + goto retry; > + > + return ret; > +} > + > static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > unsigned flags, struct iomap *iomap) > { > @@ -3502,62 +3558,14 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > } > } > } else if (flags & IOMAP_WRITE) { > - int dio_credits; > - handle_t *handle; > - int retries = 0; > - > - /* Trim mapping request to maximum we can map at once for DIO */ > - if (map.m_len > DIO_MAX_BLOCKS) > - map.m_len = DIO_MAX_BLOCKS; > - dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); > -retry: > - /* > - * Either we allocate blocks and then we don't get unwritten > - * extent so we have reserved enough credits, or the blocks > - * are already allocated and unwritten and in that case > - * extent conversion fits in the credits as well. > - */ > - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, > - dio_credits); > - if (IS_ERR(handle)) > - return PTR_ERR(handle); > - > - ret = ext4_map_blocks(handle, inode, &map, > - EXT4_GET_BLOCKS_CREATE_ZERO); > - if (ret < 0) { > - ext4_journal_stop(handle); > - if (ret == -ENOSPC && > - ext4_should_retry_alloc(inode->i_sb, &retries)) > - goto retry; > - return ret; > - } > - > - /* > - * If we added blocks beyond i_size, we need to make sure they > - * will get truncated if we crash before updating i_size in > - * ext4_iomap_end(). For faults we don't need to do that (and > - * even cannot because for orphan list operations inode_lock is > - * required) - if we happen to instantiate block beyond i_size, > - * it is because we race with truncate which has already added > - * the inode to the orphan list. > - */ > - if (!(flags & IOMAP_FAULT) && first_block + map.m_len > > - (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { > - int err; > - > - err = ext4_orphan_add(handle, inode); > - if (err < 0) { > - ext4_journal_stop(handle); > - return err; > - } > - } > - ext4_journal_stop(handle); > + ret = ext4_iomap_alloc(inode, &map, flags); > } else { > ret = ext4_map_blocks(NULL, inode, &map, 0); > - if (ret < 0) > - return ret; > } > > + if (ret < 0) > + return ret; > + > ext4_set_iomap(inode, iomap, &map, offset, length); > if (delalloc && iomap->type == IOMAP_HOLE) > iomap->type = IOMAP_DELALLOC; > -- > 2.20.1 > > --<M>--
On 10/21/19 2:48 PM, Matthew Bobrowski wrote: > In preparation for porting across the ext4 direct I/O path for reads > and writes over to the iomap infrastructure, split up the IOMAP_WRITE > chunk of code into a separate helper ext4_alloc_iomap(). This way, > when we add the necessary bits for direct I/O, we don't end up with > ext4_iomap_begin() becoming a behemoth twisty maze. > > Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Patch looks good to me. You may add: Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> > --- > fs/ext4/inode.c | 112 ++++++++++++++++++++++++++---------------------- > 1 file changed, 60 insertions(+), 52 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 0dd29ae5cc8c..3dc92bd8a944 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3442,6 +3442,62 @@ static void ext4_set_iomap(struct inode *inode, struct iomap *iomap, > } > } > > +static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map, > + unsigned int flags) > +{ > + handle_t *handle; > + u8 blkbits = inode->i_blkbits; > + int ret, dio_credits, retries = 0; > + > + /* > + * Trim the mapping request to the maximum value that we can map at > + * once for direct I/O. > + */ > + if (map->m_len > DIO_MAX_BLOCKS) > + map->m_len = DIO_MAX_BLOCKS; > + dio_credits = ext4_chunk_trans_blocks(inode, map->m_len); > + > +retry: > + /* > + * Either we allocate blocks and then don't get an unwritten extent, so > + * in that case we have reserved enough credits. Or, the blocks are > + * already allocated and and unwritten. In that case, the extent > + * conversion fits into the credits too. > + */ > + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); > + if (IS_ERR(handle)) > + return PTR_ERR(handle); > + > + ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO); > + if (ret < 0) > + goto journal_stop; > + > + /* > + * If we have allocated blocks beyond EOF, we need to ensure that > + * they're truncated if we crash before updating the inode size > + * metadata within ext4_iomap_end(). For faults, we don't need to do > + * that (and cannot due to the orphan list operations needing an > + * inode_lock()). If we happen to instantiate blocks beyond EOF, it is > + * because we race with a truncate operation, which already has added > + * the inode onto the orphan list. > + */ > + if (!(flags & IOMAP_FAULT) && map->m_lblk + map->m_len > > + (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { > + int err; > + > + err = ext4_orphan_add(handle, inode); > + if (err < 0) > + ret = err; > + } > + > +journal_stop: > + ext4_journal_stop(handle); > + if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) > + goto retry; > + > + return ret; > +} > + > static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > unsigned flags, struct iomap *iomap) > { > @@ -3502,62 +3558,14 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > } > } > } else if (flags & IOMAP_WRITE) { > - int dio_credits; > - handle_t *handle; > - int retries = 0; > - > - /* Trim mapping request to maximum we can map at once for DIO */ > - if (map.m_len > DIO_MAX_BLOCKS) > - map.m_len = DIO_MAX_BLOCKS; > - dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); > -retry: > - /* > - * Either we allocate blocks and then we don't get unwritten > - * extent so we have reserved enough credits, or the blocks > - * are already allocated and unwritten and in that case > - * extent conversion fits in the credits as well. > - */ > - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, > - dio_credits); > - if (IS_ERR(handle)) > - return PTR_ERR(handle); > - > - ret = ext4_map_blocks(handle, inode, &map, > - EXT4_GET_BLOCKS_CREATE_ZERO); > - if (ret < 0) { > - ext4_journal_stop(handle); > - if (ret == -ENOSPC && > - ext4_should_retry_alloc(inode->i_sb, &retries)) > - goto retry; > - return ret; > - } > - > - /* > - * If we added blocks beyond i_size, we need to make sure they > - * will get truncated if we crash before updating i_size in > - * ext4_iomap_end(). For faults we don't need to do that (and > - * even cannot because for orphan list operations inode_lock is > - * required) - if we happen to instantiate block beyond i_size, > - * it is because we race with truncate which has already added > - * the inode to the orphan list. > - */ > - if (!(flags & IOMAP_FAULT) && first_block + map.m_len > > - (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { > - int err; > - > - err = ext4_orphan_add(handle, inode); > - if (err < 0) { > - ext4_journal_stop(handle); > - return err; > - } > - } > - ext4_journal_stop(handle); > + ret = ext4_iomap_alloc(inode, &map, flags); > } else { > ret = ext4_map_blocks(NULL, inode, &map, 0); > - if (ret < 0) > - return ret; > } > > + if (ret < 0) > + return ret; > + > ext4_set_iomap(inode, iomap, &map, offset, length); > if (delalloc && iomap->type == IOMAP_HOLE) > iomap->type = IOMAP_DELALLOC; >
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 0dd29ae5cc8c..3dc92bd8a944 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3442,6 +3442,62 @@ static void ext4_set_iomap(struct inode *inode, struct iomap *iomap, } } +static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map, + unsigned int flags) +{ + handle_t *handle; + u8 blkbits = inode->i_blkbits; + int ret, dio_credits, retries = 0; + + /* + * Trim the mapping request to the maximum value that we can map at + * once for direct I/O. + */ + if (map->m_len > DIO_MAX_BLOCKS) + map->m_len = DIO_MAX_BLOCKS; + dio_credits = ext4_chunk_trans_blocks(inode, map->m_len); + +retry: + /* + * Either we allocate blocks and then don't get an unwritten extent, so + * in that case we have reserved enough credits. Or, the blocks are + * already allocated and and unwritten. In that case, the extent + * conversion fits into the credits too. + */ + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO); + if (ret < 0) + goto journal_stop; + + /* + * If we have allocated blocks beyond EOF, we need to ensure that + * they're truncated if we crash before updating the inode size + * metadata within ext4_iomap_end(). For faults, we don't need to do + * that (and cannot due to the orphan list operations needing an + * inode_lock()). If we happen to instantiate blocks beyond EOF, it is + * because we race with a truncate operation, which already has added + * the inode onto the orphan list. + */ + if (!(flags & IOMAP_FAULT) && map->m_lblk + map->m_len > + (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { + int err; + + err = ext4_orphan_add(handle, inode); + if (err < 0) + ret = err; + } + +journal_stop: + ext4_journal_stop(handle); + if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry; + + return ret; +} + static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, unsigned flags, struct iomap *iomap) { @@ -3502,62 +3558,14 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, } } } else if (flags & IOMAP_WRITE) { - int dio_credits; - handle_t *handle; - int retries = 0; - - /* Trim mapping request to maximum we can map at once for DIO */ - if (map.m_len > DIO_MAX_BLOCKS) - map.m_len = DIO_MAX_BLOCKS; - dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); -retry: - /* - * Either we allocate blocks and then we don't get unwritten - * extent so we have reserved enough credits, or the blocks - * are already allocated and unwritten and in that case - * extent conversion fits in the credits as well. - */ - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, - dio_credits); - if (IS_ERR(handle)) - return PTR_ERR(handle); - - ret = ext4_map_blocks(handle, inode, &map, - EXT4_GET_BLOCKS_CREATE_ZERO); - if (ret < 0) { - ext4_journal_stop(handle); - if (ret == -ENOSPC && - ext4_should_retry_alloc(inode->i_sb, &retries)) - goto retry; - return ret; - } - - /* - * If we added blocks beyond i_size, we need to make sure they - * will get truncated if we crash before updating i_size in - * ext4_iomap_end(). For faults we don't need to do that (and - * even cannot because for orphan list operations inode_lock is - * required) - if we happen to instantiate block beyond i_size, - * it is because we race with truncate which has already added - * the inode to the orphan list. - */ - if (!(flags & IOMAP_FAULT) && first_block + map.m_len > - (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { - int err; - - err = ext4_orphan_add(handle, inode); - if (err < 0) { - ext4_journal_stop(handle); - return err; - } - } - ext4_journal_stop(handle); + ret = ext4_iomap_alloc(inode, &map, flags); } else { ret = ext4_map_blocks(NULL, inode, &map, 0); - if (ret < 0) - return ret; } + if (ret < 0) + return ret; + ext4_set_iomap(inode, iomap, &map, offset, length); if (delalloc && iomap->type == IOMAP_HOLE) iomap->type = IOMAP_DELALLOC;
In preparation for porting across the ext4 direct I/O path for reads and writes over to the iomap infrastructure, split up the IOMAP_WRITE chunk of code into a separate helper ext4_alloc_iomap(). This way, when we add the necessary bits for direct I/O, we don't end up with ext4_iomap_begin() becoming a behemoth twisty maze. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> --- fs/ext4/inode.c | 112 ++++++++++++++++++++++++++---------------------- 1 file changed, 60 insertions(+), 52 deletions(-)