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Commit 4a0f5869 authored by Anton Altaparmakov's avatar Anton Altaparmakov Committed by Anton Altaparmakov
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NTFS: 

- Rename, cleanup, and improve end_buffer_read_index_async, is now
end_buffer_read_mst_async.

- Replace ntfs_dir_readpage by ntfs_mst_readpage which is a fusion of
ntfs_dir_readpage and mft.c::ntfs_mft_readpage with support for mapping
unmapped run lists within instead of calling ntfs_file_get_block.

- Throw away ntfs_mft_readpage. This now becomes aops.c::ntfs_mst_readpage
merged together with aops.c::ntfs_dir_readpage.

The effect of the above is that we have one readpage function less and that
this copes properly with the intricacies of initialized_size vs data_size vs
allocated size.

- Various cleanups.
parent 9b1edda1
Hide whitespace changes
Inline Side-by-side
Showing with 124 additions and 244 deletions
fs/ntfs/ChangeLog
View file @ 4a0f5869
......@@ -8,7 +8,7 @@ ToDo:
functions need to clone block_read_full_page and modify it to cope
with the significance of the different attribute sizes.
Still need to go through:
aops.c, dir.c
aops.c
- Find and fix bugs.
- W.r.t. s_maxbytes still need to be careful on reading/truncating as
there are dragons lurking in the details, e.g. read_inode() currently
......@@ -17,8 +17,8 @@ ToDo:
truncate the visible i_size? Will the user just get -E2BIG (or
whatever) on open()? Or will (s)he be able to open() but lseek() and
read() will fail when s_maxbytes is reached? -> Investigate this!
- Implement/allow non-resident index bitmaps in ntfs_readdir() and
consider initialized_size, etc.
- Implement/allow non-resident index bitmaps in dir.c::ntfs_readdir()
and then also consider initialized_size w.r.t. the bitmaps, etc.
- vcn_to_lcn() should somehow return the correct pointer within the
->run_list so we can get at the lcns for the following vcns, this is
strictly a speed optimization. Obviously need to keep the ->run_list
......@@ -46,6 +46,15 @@ tng-0.0.9 - Work in progress
clean up compress.c a little, removing some uncommented/unused debug
code.
- Tidy up dir.c a little bit.
- Merge mft.c::ntfs_mft_readpage() and aops.c::ntfs_index_readpage()
creating aops.c::ntfs_mst_readpage(), improving the handling of
holes and overflow in the process and implementing the correct
equivalent of ntfs_file_get_block() in ntfs_mst_readpage() itself.
I am aiming for correctness at the moment. Modularisation can come
later.
- Rename aops.c::end_buffer_read_index_async() to
end_buffer_read_mst_async() and optimize the overflow checking and
handling.
- Don't bother getting the run list in inode.c::ntfs_read_inode().
......
fs/ntfs/aops.c
View file @ 4a0f5869
......@@ -66,10 +66,6 @@ int ntfs_file_get_block(struct inode *vi, const sector_t blk,
int ofs;
BOOL is_retry = FALSE;
//ntfs_debug("Entering for blk 0x%lx.", blk);
//printk(KERN_DEBUG "NTFS: " __FUNCTION__ "(): Entering for blk "
// "0x%lx.\n", blk);
bh->b_dev = vi->i_dev;
bh->b_blocknr = -1;
bh->b_state &= ~(1UL << BH_Mapped);
......@@ -406,7 +402,7 @@ static int ntfs_mftbmp_readpage(ntfs_volume *vol, struct page *page)
}
/**
* end_buffer_read_index_async - async io completion for reading index records
* end_buffer_read_mst_async - async io completion for reading index records
* @bh: buffer head on which io is completed
* @uptodate: whether @bh is now uptodate or not
*
......@@ -425,7 +421,7 @@ static int ntfs_mftbmp_readpage(ntfs_volume *vol, struct page *page)
* size of the volume (vol->mft_record_size), and index_block_size_bits to
* mft_record_size_bits, respectively.
*/
void end_buffer_read_index_async(struct buffer_head *bh, int uptodate)
static void end_buffer_read_mst_async(struct buffer_head *bh, int uptodate)
{
static spinlock_t page_uptodate_lock = SPIN_LOCK_UNLOCKED;
unsigned long flags;
......@@ -438,36 +434,20 @@ void end_buffer_read_index_async(struct buffer_head *bh, int uptodate)
page = bh->b_page;
ni = NTFS_I(page->mapping->host);
if (likely(uptodate)) {
/*
* The below code is very cpu intensive so we add an extra
* check to ensure it is only run when processing buffer heads
* in pages reaching beyond the initialized data size.
*/
if ((page->index + 1) << PAGE_CACHE_SHIFT >
ni->initialized_size) {
s64 file_ofs;
s64 file_ofs;
file_ofs = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh);
/* Check for the current buffer head overflowing. */
if (file_ofs + bh->b_size > ni->initialized_size) {
char *addr;
int page_ofs;
int ofs = 0;
if (file_ofs < ni->initialized_size)
ofs = ni->initialized_size - file_ofs;
addr = kmap_atomic(page, KM_BIO_IRQ);
BUG_ON(bh->b_data < addr);
BUG_ON(bh->b_data + bh->b_size > addr +
PAGE_CACHE_SIZE);
page_ofs = bh->b_data - addr;
file_ofs = (page->index << PAGE_CACHE_SHIFT) + page_ofs;
/* Check for the current buffer head overflowing. */
if (file_ofs + bh->b_size > ni->initialized_size) {
int bh_ofs = 0;
if (file_ofs < ni->initialized_size) {
bh_ofs = ni->initialized_size -
file_ofs;
BUG_ON(bh_ofs < 0);
BUG_ON(bh_ofs >= bh->b_size);
}
memset(bh->b_data + bh_ofs, 0,
bh->b_size - bh_ofs);
flush_dcache_page(page);
}
memset(addr + bh_offset(bh) + ofs, 0,
bh->b_size - ofs);
flush_dcache_page(page);
kunmap_atomic(addr, KM_BIO_IRQ);
}
} else
......@@ -505,9 +485,9 @@ void end_buffer_read_index_async(struct buffer_head *bh, int uptodate)
unsigned int i, recs, nr_err = 0;
u32 rec_size;
addr = kmap_atomic(page, KM_BIO_IRQ);
rec_size = ni->_IDM(index_block_size);
recs = PAGE_CACHE_SIZE / rec_size;
addr = kmap_atomic(page, KM_BIO_IRQ);
for (i = 0; i < recs; i++) {
if (!post_read_mst_fixup((NTFS_RECORD*)(addr +
i * rec_size), rec_size))
......@@ -522,7 +502,7 @@ void end_buffer_read_index_async(struct buffer_head *bh, int uptodate)
}
flush_dcache_page(page);
kunmap_atomic(addr, KM_BIO_IRQ);
if (!nr_err && recs)
if (likely(!nr_err && recs))
SetPageUptodate(page);
else {
ntfs_error(ni->vol->sb, "Setting page error, index "
......@@ -538,90 +518,126 @@ void end_buffer_read_index_async(struct buffer_head *bh, int uptodate)
}
/**
* ntfs_dir_readpage - fill a @page of a directory with data from the device
* @dir: open directory to which the page @page belongs
* ntfs_mst_readpage - fill a @page of the mft or a directory with data
* @file: open file/directory to which the page @page belongs or NULL
* @page: page cache page to fill with data
*
* Fill the page @page of the open directory @dir. We read each buffer
* asynchronously and when all buffers are read in our io completion
* handler end_buffer_read_index_block_async() automatically applies the mst
* fixups to the page before finally marking it uptodate and unlocking it.
* Readpage method for the VFS address space operations.
*
* Fill the page @page of the $MFT or the open directory @dir. We read each
* buffer asynchronously and when all buffers are read in our io completion
* handler end_buffer_read_mst_async() automatically applies the mst fixups to
* the page before finally marking it uptodate and unlocking it.
*
* Contains an adapted version of fs/buffer.c::block_read_full_page(), a
* generic "read page" function for block devices that have the normal
* get_block functionality. This is most of the block device filesystems.
* Reads the page asynchronously --- the unlock_buffer() and
* mark_buffer_uptodate() functions propagate buffer state into the
* page struct once IO has completed.
* Contains an adapted version of fs/buffer.c::block_read_full_page().
*
* TODO:/FIXME: The current implementation is simple but wasteful as we perform
* actual i/o from disk for all data up to allocated size completely ignoring
* the fact that initialized size, and data size for that matter, may well be
* lower and hence there is no point in reading them in. We can just zero the
* page range, which is what is currently done in our async i/o completion
* handler anyway, once the read from disk completes. However, I am not sure how
* to setup the buffer heads in that case, so for now we do the pointless i/o.
* Any help with this would be appreciated...
*/
static int ntfs_dir_readpage(struct file *dir, struct page *page)
int ntfs_mst_readpage(struct file *dir, struct page *page)
{
VCN vcn;
LCN lcn;
struct inode *vi;
ntfs_inode *ni;
struct super_block *sb;
ntfs_volume *vol;
struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
sector_t iblock, lblock;
unsigned int blocksize, blocks, nr_bu;
int nr, i;
unsigned int blocksize, blocks, vcn_ofs;
int i, nr;
unsigned char blocksize_bits;
/* The page must be locked. */
if (!PageLocked(page))
PAGE_BUG(page);
/*
* Get the VFS/ntfs inodes, the super block and ntfs volume associated
* with the page.
*/
/* Get the VFS and ntfs nodes as well as the super blocks for page. */
vi = page->mapping->host;
ni = NTFS_I(vi);
sb = vi->i_sb;
vol = NTFS_SB(sb);
/* We need to create buffers for the page so we can do low level io. */
blocksize = sb->s_blocksize;
blocksize_bits = sb->s_blocksize_bits;
if (!page->buffers)
create_empty_buffers(page, blocksize);
else
ntfs_error(sb, "Page (index 0x%lx) already has buffers.",
page->index);
/* We need to create buffers for the page so we can do low level io. */
create_empty_buffers(page, blocksize);
nr_bu = blocks = PAGE_CACHE_SIZE >> blocksize_bits;
blocks = PAGE_CACHE_SIZE >> blocksize_bits;
iblock = page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
lblock = (vi->i_size + blocksize - 1) >> blocksize_bits;
lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits;
bh = head = page->buffers;
BUG_ON(!bh);
#ifdef DEBUG
if (unlikely(!ni->run_list.rl && !ni->mft_no))
panic("NTFS: $MFT/$DATA run list has been unmapped! This is a "
"very serious bug! Cannot continue...");
#endif
/* Loop through all the buffers in the page. */
i = nr = 0;
do {
if (buffer_uptodate(bh)) {
nr_bu--;
continue;
}
if (!buffer_mapped(bh)) {
/* Is the block within the allowed limits? */
if (iblock < lblock) {
/* Remap the inode offset to its disk block. */
if (ntfs_file_get_block(vi, iblock, bh, 0))
continue;
}
if (!buffer_mapped(bh)) {
/*
* Error. Zero this portion of the page and set
* the buffer uptodate.
*/
memset(kmap(page) + i * blocksize, 0,
blocksize);
flush_dcache_page(page);
kunmap(page);
set_bit(BH_Uptodate, &bh->b_state);
BUG_ON(buffer_mapped(bh) || buffer_uptodate(bh));
bh->b_dev = vi->i_dev;
/* Is the block within the allowed limits? */
if (iblock < lblock) {
BOOL is_retry = FALSE;
/* Convert iblock into corresponding vcn and offset. */
vcn = (VCN)iblock << blocksize_bits >>
vol->cluster_size_bits;
vcn_ofs = ((VCN)iblock << blocksize_bits) &
vol->cluster_size_mask;
retry_remap:
/* Convert the vcn to the corresponding lcn. */
down_read(&ni->run_list.lock);
lcn = vcn_to_lcn(ni->run_list.rl, vcn);
up_read(&ni->run_list.lock);
/* Successful remap. */
if (lcn >= 0) {
/* Setup buffer head to correct block. */
bh->b_blocknr = ((lcn << vol->cluster_size_bits)
+ vcn_ofs) >> blocksize_bits;
bh->b_state |= (1UL << BH_Mapped);
arr[nr++] = bh;
continue;
}
/* The buffer might have been updated synchronousle. */
if (buffer_uptodate(bh))
continue;
/* It is a hole, need to zero it. */
if (lcn == LCN_HOLE)
goto handle_hole;
/* If first try and run list unmapped, map and retry. */
if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
is_retry = TRUE;
if (!map_run_list(ni, vcn))
goto retry_remap;
}
/* Hard error, zero out region. */
ntfs_error(sb, "vcn_to_lcn(vcn = 0x%Lx) failed with "
"error code 0x%Lx%s.", (long long)vcn,
(long long)-lcn, is_retry ? " even "
"after retrying" : "");
// FIXME: Depending on vol->on_errors, do something.
}
arr[nr++] = bh;
/*
* Either iblock was outside lblock limits or vcn_to_lcn()
* returned error. Just zero that portion of the page and set
* the buffer uptodate.
*/
handle_hole:
bh->b_blocknr = -1UL;
bh->b_state &= ~(1UL << BH_Mapped);
memset(kmap(page) + i * blocksize, 0, blocksize);
flush_dcache_page(page);
kunmap(page);
set_bit(BH_Uptodate, &bh->b_state);
} while (i++, iblock++, (bh = bh->b_this_page) != head);
/* Check we have at least one buffer ready for io. */
......@@ -630,25 +646,16 @@ static int ntfs_dir_readpage(struct file *dir, struct page *page)
for (i = 0; i < nr; i++) {
struct buffer_head *tbh = arr[i];
lock_buffer(tbh);
tbh->b_end_io = end_buffer_read_index_async;
tbh->b_end_io = end_buffer_read_mst_async;
mark_buffer_async(tbh, 1);
}
/* Finally, start io on the buffers. */
for (i = 0; i < nr; i++)
submit_bh(READ, arr[i]);
/* We are done. */
return 0;
}
if (!nr_bu) {
ntfs_debug("All buffers in the page were already uptodate, "
"assuming mst fixups were already applied.");
SetPageUptodate(page);
UnlockPage(page);
return 0;
}
ntfs_error(sb, "No io was scheduled on any of the buffers in the page, "
"but buffers were not all uptodate to start with. "
"Setting page error flag and returning io error.");
/* We didn't schedule any io on any of the buffers. */
ntfs_error(sb, "No I/O was scheduled on any buffers. Page I/O error.");
SetPageError(page);
UnlockPage(page);
return -EIO;
......@@ -662,12 +669,11 @@ struct address_space_operations ntfs_file_aops = {
disk request queue. */
prepare_write: NULL, /* . */
commit_write: NULL, /* . */
//truncatepage: NULL, /* . */
};
typedef int readpage_t(struct file *, struct page *);
/* FIXME: Kludge: Address space operations for accessing mftbmp. */
/* Address space operations for accessing mftbmp. */
struct address_space_operations ntfs_mftbmp_aops = {
writepage: NULL, /* Write dirty page to disk. */
readpage: (readpage_t*)ntfs_mftbmp_readpage, /* Fill page with
......@@ -676,7 +682,6 @@ struct address_space_operations ntfs_mftbmp_aops = {
disk request queue. */
prepare_write: NULL, /* . */
commit_write: NULL, /* . */
//truncatepage: NULL, /* . */
};
/*
......@@ -687,11 +692,10 @@ struct address_space_operations ntfs_mftbmp_aops = {
*/
struct address_space_operations ntfs_dir_aops = {
writepage: NULL, /* Write dirty page to disk. */
readpage: ntfs_dir_readpage, /* Fill page with data. */
readpage: ntfs_mst_readpage, /* Fill page with data. */
sync_page: block_sync_page, /* Currently, just unplugs the
disk request queue. */
prepare_write: NULL, /* . */
commit_write: NULL, /* . */
//truncatepage: NULL, /* . */
};
fs/ntfs/mft.c
View file @ 4a0f5869
......@@ -136,136 +136,8 @@ int format_mft_record(ntfs_inode *ni, MFT_RECORD *mft_rec)
return 0;
}
/**
* ntfs_mft_readpage - read a page of the data attribute of $MFT
* @file: open file to which the page @page belongs or NULL
* @page: page cache page to fill with data
*
* Readpage method for the VFS address space operations.
*
* ntfs_mft_readpage() reads the page specified by @page and returns 0 on
* success or -EIO on error.
*
* Note, we only setup asynchronous I/O on the page and return. I/O completion
* is signalled via our asynchronous I/O completion handler
* end_buffer_read_index_async(). We also take care of the nitty gritty
* details towards the end of the file and zero out non-initialized regions.
*
* TODO:/FIXME: The current implementation is simple but wasteful as we perform
* actual i/o from disk for all data up to allocated size completely ignoring
* the fact that initialized size, and data size for that matter, may well be
* lower and hence there is no point in reading them in. We can just zero the
* page range, which is what is currently done in our async i/o completion
* handler anyway once the read from disk completes. However, I am not sure how
* to setup the buffer heads in that case, so for now we do the pointless i/o.
* Any help with this would be appreciated...
*/
static int ntfs_mft_readpage(struct file *file, struct page *page)
{
VCN vcn;
LCN lcn;
struct inode *vi;
ntfs_inode *ni;
struct super_block *sb;
ntfs_volume *vol;
struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
sector_t iblock, lblock;
unsigned int blocksize, blocks, vcn_ofs;
int i, nr;
unsigned char blocksize_bits;
/* The page must be locked. */
if (!PageLocked(page))
PAGE_BUG(page);
/* Get the VFS and ntfs inodes as well as the super blocks for page. */
vi = page->mapping->host;
ni = NTFS_I(vi);
sb = vi->i_sb;
vol = NTFS_SB(sb);
blocksize = sb->s_blocksize;
blocksize_bits = sb->s_blocksize_bits;
if (!page->buffers)
create_empty_buffers(page, blocksize);
blocks = PAGE_CACHE_SIZE >> blocksize_bits;
iblock = page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits;
bh = head = page->buffers;
BUG_ON(!bh);
#ifdef DEBUG
if (!ni->run_list.rl)
panic("NTFS: $MFT/$DATA run list has been unmapped! This is a "
"very serious bug! Cannot continue...");
#endif
nr = i = 0;
/* Loop through all the buffers in the page. */
do {
if (buffer_mapped(bh))
BUG();
/* Is the block within the allowed limits? */
if (iblock < lblock) {
/* Convert iblock into corresponding vcn and offset. */
vcn = (VCN)iblock << blocksize_bits >>
vol->cluster_size_bits;
vcn_ofs = ((VCN)iblock << blocksize_bits) &
vol->cluster_size_mask;
/* Convert the vcn to the corresponding lcn. */
down_read(&ni->run_list.lock);
lcn = vcn_to_lcn(ni->run_list.rl, vcn);
up_read(&ni->run_list.lock);
if (lcn >= 0) {
/* Setup buffer head to correct block. */
bh->b_dev = vi->i_dev;
bh->b_blocknr = ((lcn << vol->cluster_size_bits)
+ vcn_ofs) >> blocksize_bits;
bh->b_state |= (1UL << BH_Mapped);
arr[nr++] = bh;
continue;
}
ntfs_error(sb, "vcn_to_lcn(vcn = 0x%Lx) failed with "
"error code 0x%Lx.", (long long)vcn,
(long long)-lcn);
// FIXME: Depending on vol->on_errors, do something.
}
/*
* Either iblock was outside lblock limits or vcn_to_lcn()
* returned error. Just zero that portion of the page and set
* the buffer uptodate.
*/
bh->b_dev = vi->i_dev;
bh->b_blocknr = -1UL;
bh->b_state &= ~(1UL << BH_Mapped);
memset(kmap(page) + i * blocksize, 0, blocksize);
flush_dcache_page(page);
kunmap(page);
set_bit(BH_Uptodate, &bh->b_state);
} while (i++, iblock++, (bh = bh->b_this_page) != head);
/* Check we have at least one buffer ready for io. */
if (nr) {
/* Lock the buffers. */
for (i = 0; i < nr; i++) {
struct buffer_head *tbh = arr[i];
lock_buffer(tbh);
tbh->b_end_io = end_buffer_read_index_async;
mark_buffer_async(tbh, 1);
}
/* And start io on the buffers. */
for (i = 0; i < nr; i++)
submit_bh(READ, arr[i]);
return 0;
}
/* We didn't schedule any io on any of the buffers. */
ntfs_error(sb, "No I/O was scheduled on any buffers. Page I/O error.");
SetPageError(page);
UnlockPage(page);
return -EIO;
}
/* From fs/ntfs/aops.c */
extern int ntfs_mst_readpage(struct file *, struct page *);
/**
* ntfs_mft_aops - address space operations for access to $MFT
......@@ -275,7 +147,7 @@ static int ntfs_mft_readpage(struct file *file, struct page *page)
*/
struct address_space_operations ntfs_mft_aops = {
writepage: NULL, /* Write dirty page to disk. */
readpage: ntfs_mft_readpage, /* Fill page with data. */
readpage: ntfs_mst_readpage, /* Fill page with data. */
sync_page: block_sync_page, /* Currently, just unplugs the
disk request queue. */
prepare_write: NULL, /* . */
......@@ -390,7 +262,7 @@ static inline void unmap_mft_record_page(ntfs_inode *ni)
* necessary, increments the use count on the page so that it cannot disappear
* under us and returns a reference to the page cache page).
*
* If read_cache_page() invokes ntfs_mft_readpage() to load the page from disk,
* If read_cache_page() invokes ntfs_mst_readpage() to load the page from disk,
* it sets PG_locked and clears PG_uptodate on the page. Once I/O has
* completed and the post-read mst fixups on each mft record in the page have
* been performed, the page gets PG_uptodate set and PG_locked cleared (this is
......
fs/ntfs/ntfs.h
View file @ 4a0f5869
......@@ -200,11 +200,6 @@ static inline struct page *ntfs_map_page(struct address_space *mapping,
/* Declarations of functions and global variables. */
/* From fs/ntfs/aops.c */
extern int ntfs_file_get_block(struct inode *vi, const sector_t blk,
struct buffer_head *bh, const int create);
extern void end_buffer_read_index_async(struct buffer_head *bh, int uptodate);
/* From fs/ntfs/compress.c */
extern int ntfs_file_read_compressed_block(struct page *page);
......
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