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Merge branch 'rh/dioread-nolock-1k' into dev
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Theodore Ts'o committed Nov 1, 2019
2 parents 7855a57 + c33fbe8 commit 0d0a60c
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Showing 5 changed files with 208 additions and 110 deletions.
13 changes: 11 additions & 2 deletions fs/ext4/ext4.h
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Original file line number Diff line number Diff line change
Expand Up @@ -198,6 +198,12 @@ struct ext4_system_blocks {
*/
#define EXT4_IO_END_UNWRITTEN 0x0001

struct ext4_io_end_vec {
struct list_head list; /* list of io_end_vec */
loff_t offset; /* offset in the file */
ssize_t size; /* size of the extent */
};

/*
* For converting unwritten extents on a work queue. 'handle' is used for
* buffered writeback.
Expand All @@ -211,8 +217,7 @@ typedef struct ext4_io_end {
* bios covering the extent */
unsigned int flag; /* unwritten or not */
atomic_t count; /* reference counter */
loff_t offset; /* offset in the file */
ssize_t size; /* size of the extent */
struct list_head list_vec; /* list of ext4_io_end_vec */
} ext4_io_end_t;

struct ext4_io_submit {
Expand Down Expand Up @@ -3264,6 +3269,8 @@ extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
loff_t len);
extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
loff_t offset, ssize_t len);
extern int ext4_convert_unwritten_io_end_vec(handle_t *handle,
ext4_io_end_t *io_end);
extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map, int flags);
extern int ext4_ext_calc_metadata_amount(struct inode *inode,
Expand Down Expand Up @@ -3322,6 +3329,8 @@ extern int ext4_bio_write_page(struct ext4_io_submit *io,
int len,
struct writeback_control *wbc,
bool keep_towrite);
extern struct ext4_io_end_vec *ext4_alloc_io_end_vec(ext4_io_end_t *io_end);
extern struct ext4_io_end_vec *ext4_last_io_end_vec(ext4_io_end_t *io_end);

/* mmp.c */
extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
Expand Down
49 changes: 34 additions & 15 deletions fs/ext4/extents.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4962,23 +4962,13 @@ int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
int ret = 0;
int ret2 = 0;
struct ext4_map_blocks map;
unsigned int credits, blkbits = inode->i_blkbits;
unsigned int blkbits = inode->i_blkbits;
unsigned int credits = 0;

map.m_lblk = offset >> blkbits;
max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);

/*
* This is somewhat ugly but the idea is clear: When transaction is
* reserved, everything goes into it. Otherwise we rather start several
* smaller transactions for conversion of each extent separately.
*/
if (handle) {
handle = ext4_journal_start_reserved(handle,
EXT4_HT_EXT_CONVERT);
if (IS_ERR(handle))
return PTR_ERR(handle);
credits = 0;
} else {
if (!handle) {
/*
* credits to insert 1 extent into extent tree
*/
Expand Down Expand Up @@ -5009,11 +4999,40 @@ int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
if (ret <= 0 || ret2)
break;
}
if (!credits)
ret2 = ext4_journal_stop(handle);
return ret > 0 ? ret2 : ret;
}

int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
{
int ret, err = 0;
struct ext4_io_end_vec *io_end_vec;

/*
* This is somewhat ugly but the idea is clear: When transaction is
* reserved, everything goes into it. Otherwise we rather start several
* smaller transactions for conversion of each extent separately.
*/
if (handle) {
handle = ext4_journal_start_reserved(handle,
EXT4_HT_EXT_CONVERT);
if (IS_ERR(handle))
return PTR_ERR(handle);
}

list_for_each_entry(io_end_vec, &io_end->list_vec, list) {
ret = ext4_convert_unwritten_extents(handle, io_end->inode,
io_end_vec->offset,
io_end_vec->size);
if (ret)
break;
}

if (handle)
err = ext4_journal_stop(handle);

return ret < 0 ? ret : err;
}

/*
* If newes is not existing extent (newes->ec_pblk equals zero) find
* delayed extent at start of newes and update newes accordingly and
Expand Down
136 changes: 90 additions & 46 deletions fs/ext4/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2340,6 +2340,75 @@ static int mpage_process_page_bufs(struct mpage_da_data *mpd,
return lblk < blocks;
}

/*
* mpage_process_page - update page buffers corresponding to changed extent and
* may submit fully mapped page for IO
*
* @mpd - description of extent to map, on return next extent to map
* @m_lblk - logical block mapping.
* @m_pblk - corresponding physical mapping.
* @map_bh - determines on return whether this page requires any further
* mapping or not.
* Scan given page buffers corresponding to changed extent and update buffer
* state according to new extent state.
* We map delalloc buffers to their physical location, clear unwritten bits.
* If the given page is not fully mapped, we update @map to the next extent in
* the given page that needs mapping & return @map_bh as true.
*/
static int mpage_process_page(struct mpage_da_data *mpd, struct page *page,
ext4_lblk_t *m_lblk, ext4_fsblk_t *m_pblk,
bool *map_bh)
{
struct buffer_head *head, *bh;
ext4_io_end_t *io_end = mpd->io_submit.io_end;
ext4_lblk_t lblk = *m_lblk;
ext4_fsblk_t pblock = *m_pblk;
int err = 0;
int blkbits = mpd->inode->i_blkbits;
ssize_t io_end_size = 0;
struct ext4_io_end_vec *io_end_vec = ext4_last_io_end_vec(io_end);

bh = head = page_buffers(page);
do {
if (lblk < mpd->map.m_lblk)
continue;
if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
/*
* Buffer after end of mapped extent.
* Find next buffer in the page to map.
*/
mpd->map.m_len = 0;
mpd->map.m_flags = 0;
io_end_vec->size += io_end_size;
io_end_size = 0;

err = mpage_process_page_bufs(mpd, head, bh, lblk);
if (err > 0)
err = 0;
if (!err && mpd->map.m_len && mpd->map.m_lblk > lblk) {
io_end_vec = ext4_alloc_io_end_vec(io_end);
io_end_vec->offset = mpd->map.m_lblk << blkbits;
}
*map_bh = true;
goto out;
}
if (buffer_delay(bh)) {
clear_buffer_delay(bh);
bh->b_blocknr = pblock++;
}
clear_buffer_unwritten(bh);
io_end_size += (1 << blkbits);
} while (lblk++, (bh = bh->b_this_page) != head);

io_end_vec->size += io_end_size;
io_end_size = 0;
*map_bh = false;
out:
*m_lblk = lblk;
*m_pblk = pblock;
return err;
}

/*
* mpage_map_buffers - update buffers corresponding to changed extent and
* submit fully mapped pages for IO
Expand All @@ -2359,12 +2428,12 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
struct pagevec pvec;
int nr_pages, i;
struct inode *inode = mpd->inode;
struct buffer_head *head, *bh;
int bpp_bits = PAGE_SHIFT - inode->i_blkbits;
pgoff_t start, end;
ext4_lblk_t lblk;
sector_t pblock;
ext4_fsblk_t pblock;
int err;
bool map_bh = false;

start = mpd->map.m_lblk >> bpp_bits;
end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
Expand All @@ -2380,57 +2449,29 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
for (i = 0; i < nr_pages; i++) {
struct page *page = pvec.pages[i];

bh = head = page_buffers(page);
do {
if (lblk < mpd->map.m_lblk)
continue;
if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
/*
* Buffer after end of mapped extent.
* Find next buffer in the page to map.
*/
mpd->map.m_len = 0;
mpd->map.m_flags = 0;
/*
* FIXME: If dioread_nolock supports
* blocksize < pagesize, we need to make
* sure we add size mapped so far to
* io_end->size as the following call
* can submit the page for IO.
*/
err = mpage_process_page_bufs(mpd, head,
bh, lblk);
pagevec_release(&pvec);
if (err > 0)
err = 0;
return err;
}
if (buffer_delay(bh)) {
clear_buffer_delay(bh);
bh->b_blocknr = pblock++;
}
clear_buffer_unwritten(bh);
} while (lblk++, (bh = bh->b_this_page) != head);

err = mpage_process_page(mpd, page, &lblk, &pblock,
&map_bh);
/*
* FIXME: This is going to break if dioread_nolock
* supports blocksize < pagesize as we will try to
* convert potentially unmapped parts of inode.
* If map_bh is true, means page may require further bh
* mapping, or maybe the page was submitted for IO.
* So we return to call further extent mapping.
*/
mpd->io_submit.io_end->size += PAGE_SIZE;
if (err < 0 || map_bh == true)
goto out;
/* Page fully mapped - let IO run! */
err = mpage_submit_page(mpd, page);
if (err < 0) {
pagevec_release(&pvec);
return err;
}
if (err < 0)
goto out;
}
pagevec_release(&pvec);
}
/* Extent fully mapped and matches with page boundary. We are done. */
mpd->map.m_len = 0;
mpd->map.m_flags = 0;
return 0;
out:
pagevec_release(&pvec);
return err;
}

static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
Expand Down Expand Up @@ -2510,9 +2551,10 @@ static int mpage_map_and_submit_extent(handle_t *handle,
int err;
loff_t disksize;
int progress = 0;
ext4_io_end_t *io_end = mpd->io_submit.io_end;
struct ext4_io_end_vec *io_end_vec = ext4_alloc_io_end_vec(io_end);

mpd->io_submit.io_end->offset =
((loff_t)map->m_lblk) << inode->i_blkbits;
io_end_vec->offset = ((loff_t)map->m_lblk) << inode->i_blkbits;
do {
err = mpage_map_one_extent(handle, mpd);
if (err < 0) {
Expand Down Expand Up @@ -3613,6 +3655,7 @@ static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
ssize_t size, void *private)
{
ext4_io_end_t *io_end = private;
struct ext4_io_end_vec *io_end_vec;

/* if not async direct IO just return */
if (!io_end)
Expand All @@ -3630,8 +3673,9 @@ static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
ext4_clear_io_unwritten_flag(io_end);
size = 0;
}
io_end->offset = offset;
io_end->size = size;
io_end_vec = ext4_alloc_io_end_vec(io_end);
io_end_vec->offset = offset;
io_end_vec->size = size;
ext4_put_io_end(io_end);

return 0;
Expand Down
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