* aops.c - NTFS kernel address space operations and page cache handling.
* Part of the Linux-NTFS project.
*
- * Copyright (c) 2001-2004 Anton Altaparmakov
+ * Copyright (c) 2001-2006 Anton Altaparmakov
* Copyright (c) 2002 Richard Russon
*
* This program/include file is free software; you can redistribute it and/or
*/
#include <linux/errno.h>
+#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/buffer_head.h>
-
+#include <linux/writeback.h>
+#include <linux/bit_spinlock.h>
+
+#include "aops.h"
+#include "attrib.h"
+#include "debug.h"
+#include "inode.h"
+#include "mft.h"
+#include "runlist.h"
+#include "types.h"
#include "ntfs.h"
/**
* @uptodate: whether @bh is now uptodate or not
*
* Asynchronous I/O completion handler for reading pages belonging to the
- * attribute address space of an inode. The inodes can either be files or
+ * attribute address space of an inode. The inodes can either be files or
* directories or they can be fake inodes describing some attribute.
*
* If NInoMstProtected(), perform the post read mst fixups when all IO on the
* page has been completed and mark the page uptodate or set the error bit on
- * the page. To determine the size of the records that need fixing up, we cheat
- * a little bit by setting the index_block_size in ntfs_inode to the ntfs
+ * the page. To determine the size of the records that need fixing up, we
+ * cheat a little bit by setting the index_block_size in ntfs_inode to the ntfs
* record size, and index_block_size_bits, to the log(base 2) of the ntfs
* record size.
*/
static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
{
- static spinlock_t page_uptodate_lock = SPIN_LOCK_UNLOCKED;
unsigned long flags;
- struct buffer_head *tmp;
+ struct buffer_head *first, *tmp;
struct page *page;
+ struct inode *vi;
ntfs_inode *ni;
int page_uptodate = 1;
page = bh->b_page;
- ni = NTFS_I(page->mapping->host);
+ vi = page->mapping->host;
+ ni = NTFS_I(vi);
if (likely(uptodate)) {
- s64 file_ofs;
+ loff_t i_size;
+ s64 file_ofs, init_size;
set_buffer_uptodate(bh);
- file_ofs = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh);
+ file_ofs = ((s64)page->index << PAGE_CACHE_SHIFT) +
+ bh_offset(bh);
+ read_lock_irqsave(&ni->size_lock, flags);
+ init_size = ni->initialized_size;
+ i_size = i_size_read(vi);
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (unlikely(init_size > i_size)) {
+ /* Race with shrinking truncate. */
+ init_size = i_size;
+ }
/* Check for the current buffer head overflowing. */
- if (file_ofs + bh->b_size > ni->initialized_size) {
- char *addr;
- int ofs = 0;
-
- if (file_ofs < ni->initialized_size)
- ofs = ni->initialized_size - file_ofs;
- addr = kmap_atomic(page, KM_BIO_SRC_IRQ);
- memset(addr + bh_offset(bh) + ofs, 0, bh->b_size - ofs);
+ if (unlikely(file_ofs + bh->b_size > init_size)) {
+ u8 *kaddr;
+ int ofs;
+
+ ofs = 0;
+ if (file_ofs < init_size)
+ ofs = init_size - file_ofs;
+ kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
+ memset(kaddr + bh_offset(bh) + ofs, 0,
+ bh->b_size - ofs);
+ kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
flush_dcache_page(page);
- kunmap_atomic(addr, KM_BIO_SRC_IRQ);
}
} else {
clear_buffer_uptodate(bh);
- ntfs_error(ni->vol->sb, "Buffer I/O error, logical block %llu.",
- (unsigned long long)bh->b_blocknr);
SetPageError(page);
+ ntfs_error(ni->vol->sb, "Buffer I/O error, logical block "
+ "0x%llx.", (unsigned long long)bh->b_blocknr);
}
-
- spin_lock_irqsave(&page_uptodate_lock, flags);
+ first = page_buffers(page);
+ local_irq_save(flags);
+ bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- spin_unlock_irqrestore(&page_uptodate_lock, flags);
+ bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+ local_irq_restore(flags);
/*
* If none of the buffers had errors then we can set the page uptodate,
* but we first have to perform the post read mst fixups, if the
* attribute is mst protected, i.e. if NInoMstProteced(ni) is true.
+ * Note we ignore fixup errors as those are detected when
+ * map_mft_record() is called which gives us per record granularity
+ * rather than per page granularity.
*/
if (!NInoMstProtected(ni)) {
if (likely(page_uptodate && !PageError(page)))
SetPageUptodate(page);
} else {
- char *addr;
- unsigned int i, recs, nr_err;
+ u8 *kaddr;
+ unsigned int i, recs;
u32 rec_size;
rec_size = ni->itype.index.block_size;
recs = PAGE_CACHE_SIZE / rec_size;
- addr = kmap_atomic(page, KM_BIO_SRC_IRQ);
- for (i = nr_err = 0; i < recs; i++) {
- if (likely(!post_read_mst_fixup((NTFS_RECORD*)(addr +
- i * rec_size), rec_size)))
- continue;
- nr_err++;
- ntfs_error(ni->vol->sb, "post_read_mst_fixup() failed, "
- "corrupt %s record 0x%llx. Run chkdsk.",
- ni->mft_no ? "index" : "mft",
- (unsigned long long)(((s64)page->index
- << PAGE_CACHE_SHIFT >>
- ni->itype.index.block_size_bits) + i));
- }
+ /* Should have been verified before we got here... */
+ BUG_ON(!recs);
+ kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
+ for (i = 0; i < recs; i++)
+ post_read_mst_fixup((NTFS_RECORD*)(kaddr +
+ i * rec_size), rec_size);
+ kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
flush_dcache_page(page);
- kunmap_atomic(addr, KM_BIO_SRC_IRQ);
- if (likely(!PageError(page))) {
- if (likely(!nr_err && recs)) {
- if (likely(page_uptodate))
- SetPageUptodate(page);
- } else {
- ntfs_error(ni->vol->sb, "Setting page error, "
- "index 0x%lx.", page->index);
- SetPageError(page);
- }
- }
+ if (likely(page_uptodate && !PageError(page)))
+ SetPageUptodate(page);
}
unlock_page(page);
return;
still_busy:
- spin_unlock_irqrestore(&page_uptodate_lock, flags);
+ bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+ local_irq_restore(flags);
return;
}
*/
static int ntfs_read_block(struct page *page)
{
+ loff_t i_size;
VCN vcn;
LCN lcn;
+ s64 init_size;
+ struct inode *vi;
ntfs_inode *ni;
ntfs_volume *vol;
- run_list_element *rl;
+ runlist_element *rl;
struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
sector_t iblock, lblock, zblock;
+ unsigned long flags;
unsigned int blocksize, vcn_ofs;
int i, nr;
unsigned char blocksize_bits;
- ni = NTFS_I(page->mapping->host);
+ vi = page->mapping->host;
+ ni = NTFS_I(vi);
vol = ni->vol;
- blocksize_bits = VFS_I(ni)->i_blkbits;
- blocksize = 1 << blocksize_bits;
+ /* $MFT/$DATA must have its complete runlist in memory at all times. */
+ BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni));
+
+ blocksize = vol->sb->s_blocksize;
+ blocksize_bits = vol->sb->s_blocksize_bits;
- if (!page_has_buffers(page))
+ if (!page_has_buffers(page)) {
create_empty_buffers(page, blocksize, 0);
- bh = head = page_buffers(page);
- if (unlikely(!bh)) {
- unlock_page(page);
- return -ENOMEM;
+ if (unlikely(!page_has_buffers(page))) {
+ unlock_page(page);
+ return -ENOMEM;
+ }
}
+ bh = head = page_buffers(page);
+ BUG_ON(!bh);
- iblock = page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
+ /*
+ * We may be racing with truncate. To avoid some of the problems we
+ * now take a snapshot of the various sizes and use those for the whole
+ * of the function. In case of an extending truncate it just means we
+ * may leave some buffers unmapped which are now allocated. This is
+ * not a problem since these buffers will just get mapped when a write
+ * occurs. In case of a shrinking truncate, we will detect this later
+ * on due to the runlist being incomplete and if the page is being
+ * fully truncated, truncate will throw it away as soon as we unlock
+ * it so no need to worry what we do with it.
+ */
+ iblock = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
+ read_lock_irqsave(&ni->size_lock, flags);
lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits;
- zblock = (ni->initialized_size + blocksize - 1) >> blocksize_bits;
-
-#ifdef DEBUG
- if (unlikely(!ni->run_list.rl && !ni->mft_no && !NInoAttr(ni)))
- panic("NTFS: $MFT/$DATA run list has been unmapped! This is a "
- "very serious bug! Cannot continue...");
-#endif
+ init_size = ni->initialized_size;
+ i_size = i_size_read(vi);
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (unlikely(init_size > i_size)) {
+ /* Race with shrinking truncate. */
+ init_size = i_size;
+ }
+ zblock = (init_size + blocksize - 1) >> blocksize_bits;
/* Loop through all the buffers in the page. */
rl = NULL;
nr = i = 0;
do {
+ u8 *kaddr;
+ int err;
+
if (unlikely(buffer_uptodate(bh)))
continue;
if (unlikely(buffer_mapped(bh))) {
arr[nr++] = bh;
continue;
}
+ err = 0;
bh->b_bdev = vol->sb->s_bdev;
/* Is the block within the allowed limits? */
if (iblock < lblock) {
vol->cluster_size_mask;
if (!rl) {
lock_retry_remap:
- down_read(&ni->run_list.lock);
- rl = ni->run_list.rl;
+ down_read(&ni->runlist.lock);
+ rl = ni->runlist.rl;
}
if (likely(rl != NULL)) {
/* Seek to element containing target vcn. */
while (rl->length && rl[1].vcn <= vcn)
rl++;
- lcn = vcn_to_lcn(rl, vcn);
+ lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
} else
- lcn = (LCN)LCN_RL_NOT_MAPPED;
+ lcn = LCN_RL_NOT_MAPPED;
/* Successful remap. */
if (lcn >= 0) {
/* Setup buffer head to correct block. */
/* 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 first try and runlist unmapped, map and retry. */
if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
is_retry = TRUE;
/*
- * Attempt to map run list, dropping lock for
+ * Attempt to map runlist, dropping lock for
* the duration.
*/
- up_read(&ni->run_list.lock);
- if (!map_run_list(ni, vcn))
+ up_read(&ni->runlist.lock);
+ err = ntfs_map_runlist(ni, vcn);
+ if (likely(!err))
goto lock_retry_remap;
rl = NULL;
+ } else if (!rl)
+ up_read(&ni->runlist.lock);
+ /*
+ * If buffer is outside the runlist, treat it as a
+ * hole. This can happen due to concurrent truncate
+ * for example.
+ */
+ if (err == -ENOENT || lcn == LCN_ENOENT) {
+ err = 0;
+ goto handle_hole;
}
/* Hard error, zero out region. */
+ if (!err)
+ err = -EIO;
+ bh->b_blocknr = -1;
SetPageError(page);
- ntfs_error(vol->sb, "vcn_to_lcn(vcn = 0x%llx) failed "
- "with error code 0x%llx%s.",
- (unsigned long long)vcn,
- (unsigned long long)-lcn,
- is_retry ? " even after retrying" : "");
- // FIXME: Depending on vol->on_errors, do something.
+ ntfs_error(vol->sb, "Failed to read from inode 0x%lx, "
+ "attribute type 0x%x, vcn 0x%llx, "
+ "offset 0x%x because its location on "
+ "disk could not be determined%s "
+ "(error code %i).", ni->mft_no,
+ ni->type, (unsigned long long)vcn,
+ vcn_ofs, is_retry ? " even after "
+ "retrying" : "", err);
}
/*
- * Either iblock was outside lblock limits or vcn_to_lcn()
- * returned error. Just zero that portion of the page and set
- * the buffer uptodate.
+ * Either iblock was outside lblock limits or
+ * ntfs_rl_vcn_to_lcn() returned error. Just zero that portion
+ * of the page and set the buffer uptodate.
*/
handle_hole:
bh->b_blocknr = -1UL;
clear_buffer_mapped(bh);
handle_zblock:
- memset(kmap(page) + i * blocksize, 0, blocksize);
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + i * blocksize, 0, blocksize);
+ kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(page);
- kunmap(page);
- set_buffer_uptodate(bh);
+ if (likely(!err))
+ set_buffer_uptodate(bh);
} while (i++, iblock++, (bh = bh->b_this_page) != head);
/* Release the lock if we took it. */
if (rl)
- up_read(&ni->run_list.lock);
+ up_read(&ni->runlist.lock);
/* Check we have at least one buffer ready for i/o. */
if (nr) {
* for it to be read in before we can do the copy.
*
* Return 0 on success and -errno on error.
- *
- * WARNING: Do not make this function static! It is used by mft.c!
*/
-int ntfs_readpage(struct file *file, struct page *page)
+static int ntfs_readpage(struct file *file, struct page *page)
{
- s64 attr_pos;
+ loff_t i_size;
+ struct inode *vi;
ntfs_inode *ni, *base_ni;
- char *addr;
- attr_search_context *ctx;
+ u8 *kaddr;
+ ntfs_attr_search_ctx *ctx;
MFT_RECORD *mrec;
+ unsigned long flags;
u32 attr_len;
int err = 0;
+retry_readpage:
BUG_ON(!PageLocked(page));
-
/*
* This can potentially happen because we clear PageUptodate() during
* ntfs_writepage() of MstProtected() attributes.
unlock_page(page);
return 0;
}
-
- ni = NTFS_I(page->mapping->host);
-
- if (NInoNonResident(ni)) {
- /*
- * Only unnamed $DATA attributes can be compressed or
- * encrypted.
- */
- if (ni->type == AT_DATA && !ni->name_len) {
- /* If file is encrypted, deny access, just like NT4. */
- if (NInoEncrypted(ni)) {
- err = -EACCES;
- goto err_out;
- }
- /* Compressed data streams are handled in compress.c. */
- if (NInoCompressed(ni))
- return ntfs_read_compressed_block(page);
+ vi = page->mapping->host;
+ ni = NTFS_I(vi);
+ /*
+ * Only $DATA attributes can be encrypted and only unnamed $DATA
+ * attributes can be compressed. Index root can have the flags set but
+ * this means to create compressed/encrypted files, not that the
+ * attribute is compressed/encrypted. Note we need to check for
+ * AT_INDEX_ALLOCATION since this is the type of both directory and
+ * index inodes.
+ */
+ if (ni->type != AT_INDEX_ALLOCATION) {
+ /* If attribute is encrypted, deny access, just like NT4. */
+ if (NInoEncrypted(ni)) {
+ BUG_ON(ni->type != AT_DATA);
+ err = -EACCES;
+ goto err_out;
}
- /* Normal data stream. */
+ /* Compressed data streams are handled in compress.c. */
+ if (NInoNonResident(ni) && NInoCompressed(ni)) {
+ BUG_ON(ni->type != AT_DATA);
+ BUG_ON(ni->name_len);
+ return ntfs_read_compressed_block(page);
+ }
+ }
+ /* NInoNonResident() == NInoIndexAllocPresent() */
+ if (NInoNonResident(ni)) {
+ /* Normal, non-resident data stream. */
return ntfs_read_block(page);
}
- /* Attribute is resident, implying it is not compressed or encrypted. */
+ /*
+ * Attribute is resident, implying it is not compressed or encrypted.
+ * This also means the attribute is smaller than an mft record and
+ * hence smaller than a page, so can simply zero out any pages with
+ * index above 0. Note the attribute can actually be marked compressed
+ * but if it is resident the actual data is not compressed so we are
+ * ok to ignore the compressed flag here.
+ */
+ if (unlikely(page->index > 0)) {
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr, 0, PAGE_CACHE_SIZE);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ goto done;
+ }
if (!NInoAttr(ni))
base_ni = ni;
else
base_ni = ni->ext.base_ntfs_ino;
-
/* Map, pin, and lock the mft record. */
mrec = map_mft_record(base_ni);
- if (unlikely(IS_ERR(mrec))) {
+ if (IS_ERR(mrec)) {
err = PTR_ERR(mrec);
goto err_out;
}
- ctx = get_attr_search_ctx(base_ni, mrec);
+ /*
+ * If a parallel write made the attribute non-resident, drop the mft
+ * record and retry the readpage.
+ */
+ if (unlikely(NInoNonResident(ni))) {
+ unmap_mft_record(base_ni);
+ goto retry_readpage;
+ }
+ ctx = ntfs_attr_get_search_ctx(base_ni, mrec);
if (unlikely(!ctx)) {
err = -ENOMEM;
goto unm_err_out;
}
- if (unlikely(!lookup_attr(ni->type, ni->name, ni->name_len,
- IGNORE_CASE, 0, NULL, 0, ctx))) {
- err = -ENOENT;
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, 0, NULL, 0, ctx);
+ if (unlikely(err))
goto put_unm_err_out;
- }
-
- /* Starting position of the page within the attribute value. */
- attr_pos = page->index << PAGE_CACHE_SHIFT;
-
- /* The total length of the attribute value. */
attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
-
- addr = kmap(page);
- /* Copy over in bounds data, zeroing the remainder of the page. */
- if (attr_pos < attr_len) {
- u32 bytes = attr_len - attr_pos;
- if (bytes > PAGE_CACHE_SIZE)
- bytes = PAGE_CACHE_SIZE;
- else if (bytes < PAGE_CACHE_SIZE)
- memset(addr + bytes, 0, PAGE_CACHE_SIZE - bytes);
- /* Copy the data to the page. */
- memcpy(addr, attr_pos + (char*)ctx->attr +
- le16_to_cpu(
- ctx->attr->data.resident.value_offset), bytes);
- } else
- memset(addr, 0, PAGE_CACHE_SIZE);
+ read_lock_irqsave(&ni->size_lock, flags);
+ if (unlikely(attr_len > ni->initialized_size))
+ attr_len = ni->initialized_size;
+ i_size = i_size_read(vi);
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (unlikely(attr_len > i_size)) {
+ /* Race with shrinking truncate. */
+ attr_len = i_size;
+ }
+ kaddr = kmap_atomic(page, KM_USER0);
+ /* Copy the data to the page. */
+ memcpy(kaddr, (u8*)ctx->attr +
+ le16_to_cpu(ctx->attr->data.resident.value_offset),
+ attr_len);
+ /* Zero the remainder of the page. */
+ memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
flush_dcache_page(page);
- kunmap(page);
-
- SetPageUptodate(page);
+ kunmap_atomic(kaddr, KM_USER0);
put_unm_err_out:
- put_attr_search_ctx(ctx);
+ ntfs_attr_put_search_ctx(ctx);
unm_err_out:
unmap_mft_record(base_ni);
+done:
+ SetPageUptodate(page);
err_out:
unlock_page(page);
return err;
/**
* ntfs_write_block - write a @page to the backing store
* @page: page cache page to write out
+ * @wbc: writeback control structure
*
* This function is for writing pages belonging to non-resident, non-mst
* protected attributes to their backing store.
*
* Based on ntfs_read_block() and __block_write_full_page().
*/
-static int ntfs_write_block(struct writeback_control *wbc, struct page *page)
+static int ntfs_write_block(struct page *page, struct writeback_control *wbc)
{
VCN vcn;
LCN lcn;
+ s64 initialized_size;
+ loff_t i_size;
sector_t block, dblock, iblock;
struct inode *vi;
ntfs_inode *ni;
ntfs_volume *vol;
- run_list_element *rl;
+ runlist_element *rl;
struct buffer_head *bh, *head;
+ unsigned long flags;
unsigned int blocksize, vcn_ofs;
int err;
BOOL need_end_writeback;
vol = ni->vol;
ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
- "0x%lx.", vi->i_ino, ni->type, page->index);
+ "0x%lx.", ni->mft_no, ni->type, page->index);
BUG_ON(!NInoNonResident(ni));
BUG_ON(NInoMstProtected(ni));
-
- blocksize_bits = vi->i_blkbits;
- blocksize = 1 << blocksize_bits;
-
+ blocksize = vol->sb->s_blocksize;
+ blocksize_bits = vol->sb->s_blocksize_bits;
if (!page_has_buffers(page)) {
BUG_ON(!PageUptodate(page));
create_empty_buffers(page, blocksize,
(1 << BH_Uptodate) | (1 << BH_Dirty));
+ if (unlikely(!page_has_buffers(page))) {
+ ntfs_warning(vol->sb, "Error allocating page "
+ "buffers. Redirtying page so we try "
+ "again later.");
+ /*
+ * Put the page back on mapping->dirty_pages, but leave
+ * its buffers' dirty state as-is.
+ */
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+ }
}
bh = head = page_buffers(page);
- if (unlikely(!bh)) {
- ntfs_warning(vol->sb, "Error allocating page buffers. "
- "Redirtying page so we try again later.");
- /*
- * Put the page back on mapping->dirty_pages, but leave its
- * buffer's dirty state as-is.
- */
- redirty_page_for_writepage(wbc, page);
- unlock_page(page);
- return 0;
- }
+ BUG_ON(!bh);
/* NOTE: Different naming scheme to ntfs_read_block()! */
/* The first block in the page. */
- block = page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
+ block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
+
+ read_lock_irqsave(&ni->size_lock, flags);
+ i_size = i_size_read(vi);
+ initialized_size = ni->initialized_size;
+ read_unlock_irqrestore(&ni->size_lock, flags);
/* The first out of bounds block for the data size. */
- dblock = (vi->i_size + blocksize - 1) >> blocksize_bits;
+ dblock = (i_size + blocksize - 1) >> blocksize_bits;
/* The last (fully or partially) initialized block. */
- iblock = ni->initialized_size >> blocksize_bits;
+ iblock = initialized_size >> blocksize_bits;
/*
* Be very careful. We have no exclusion from __set_page_dirty_buffers
/* Make sure we have enough initialized size. */
if (unlikely((block >= iblock) &&
- (ni->initialized_size < vi->i_size))) {
+ (initialized_size < i_size))) {
/*
* If this page is fully outside initialized size, zero
* out all pages between the current initialized size
bh->b_bdev = vol->sb->s_bdev;
/* Convert block into corresponding vcn and offset. */
- vcn = (VCN)block << blocksize_bits >> vol->cluster_size_bits;
- vcn_ofs = ((VCN)block << blocksize_bits) &
- vol->cluster_size_mask;
+ vcn = (VCN)block << blocksize_bits;
+ vcn_ofs = vcn & vol->cluster_size_mask;
+ vcn >>= vol->cluster_size_bits;
if (!rl) {
lock_retry_remap:
- down_read(&ni->run_list.lock);
- rl = ni->run_list.rl;
+ down_read(&ni->runlist.lock);
+ rl = ni->runlist.rl;
}
if (likely(rl != NULL)) {
/* Seek to element containing target vcn. */
while (rl->length && rl[1].vcn <= vcn)
rl++;
- lcn = vcn_to_lcn(rl, vcn);
+ lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
} else
- lcn = (LCN)LCN_RL_NOT_MAPPED;
+ lcn = LCN_RL_NOT_MAPPED;
/* Successful remap. */
if (lcn >= 0) {
/* Setup buffer head to point to correct block. */
}
/* It is a hole, need to instantiate it. */
if (lcn == LCN_HOLE) {
+ u8 *kaddr;
+ unsigned long *bpos, *bend;
+
+ /* Check if the buffer is zero. */
+ kaddr = kmap_atomic(page, KM_USER0);
+ bpos = (unsigned long *)(kaddr + bh_offset(bh));
+ bend = (unsigned long *)((u8*)bpos + blocksize);
+ do {
+ if (unlikely(*bpos))
+ break;
+ } while (likely(++bpos < bend));
+ kunmap_atomic(kaddr, KM_USER0);
+ if (bpos == bend) {
+ /*
+ * Buffer is zero and sparse, no need to write
+ * it.
+ */
+ bh->b_blocknr = -1;
+ clear_buffer_dirty(bh);
+ continue;
+ }
// TODO: Instantiate the hole.
// clear_buffer_new(bh);
// unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
err = -EOPNOTSUPP;
break;
}
- /* If first try and run list unmapped, map and retry. */
+ /* If first try and runlist unmapped, map and retry. */
if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
is_retry = TRUE;
/*
- * Attempt to map run list, dropping lock for
+ * Attempt to map runlist, dropping lock for
* the duration.
*/
- up_read(&ni->run_list.lock);
- err = map_run_list(ni, vcn);
+ up_read(&ni->runlist.lock);
+ err = ntfs_map_runlist(ni, vcn);
if (likely(!err))
goto lock_retry_remap;
rl = NULL;
+ } else if (!rl)
+ up_read(&ni->runlist.lock);
+ /*
+ * If buffer is outside the runlist, truncate has cut it out
+ * of the runlist. Just clean and clear the buffer and set it
+ * uptodate so it can get discarded by the VM.
+ */
+ if (err == -ENOENT || lcn == LCN_ENOENT) {
+ u8 *kaddr;
+
+ bh->b_blocknr = -1;
+ clear_buffer_dirty(bh);
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + bh_offset(bh), 0, blocksize);
+ kunmap_atomic(kaddr, KM_USER0);
+ flush_dcache_page(page);
+ set_buffer_uptodate(bh);
+ err = 0;
+ continue;
}
/* Failed to map the buffer, even after retrying. */
- bh->b_blocknr = -1UL;
- ntfs_error(vol->sb, "vcn_to_lcn(vcn = 0x%llx) failed "
- "with error code 0x%llx%s.",
- (unsigned long long)vcn,
- (unsigned long long)-lcn,
- is_retry ? " even after retrying" : "");
- // FIXME: Depending on vol->on_errors, do something.
if (!err)
err = -EIO;
+ bh->b_blocknr = -1;
+ ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
+ "attribute type 0x%x, vcn 0x%llx, offset 0x%x "
+ "because its location on disk could not be "
+ "determined%s (error code %i).", ni->mft_no,
+ ni->type, (unsigned long long)vcn,
+ vcn_ofs, is_retry ? " even after "
+ "retrying" : "", err);
break;
} while (block++, (bh = bh->b_this_page) != head);
/* Release the lock if we took it. */
if (rl)
- up_read(&ni->run_list.lock);
+ up_read(&ni->runlist.lock);
/* For the error case, need to reset bh to the beginning. */
bh = head;
- /* Just an optimization, so ->readpage() isn't called later. */
+ /* Just an optimization, so ->readpage() is not called later. */
if (unlikely(!PageUptodate(page))) {
int uptodate = 1;
do {
/* Setup all mapped, dirty buffers for async write i/o. */
do {
- get_bh(bh);
if (buffer_mapped(bh) && buffer_dirty(bh)) {
lock_buffer(bh);
if (test_clear_buffer_dirty(bh)) {
BUG_ON(PageWriteback(page));
set_page_writeback(page); /* Keeps try_to_free_buffers() away. */
- unlock_page(page);
- /*
- * Submit the prepared buffers for i/o. Note the page is unlocked,
- * and the async write i/o completion handler can end_page_writeback()
- * at any time after the *first* submit_bh(). So the buffers can then
- * disappear...
- */
+ /* Submit the prepared buffers for i/o. */
need_end_writeback = TRUE;
do {
struct buffer_head *next = bh->b_this_page;
submit_bh(WRITE, bh);
need_end_writeback = FALSE;
}
- put_bh(bh);
bh = next;
} while (bh != head);
+ unlock_page(page);
/* If no i/o was started, need to end_page_writeback(). */
if (unlikely(need_end_writeback))
return err;
}
+/**
+ * ntfs_write_mst_block - write a @page to the backing store
+ * @page: page cache page to write out
+ * @wbc: writeback control structure
+ *
+ * This function is for writing pages belonging to non-resident, mst protected
+ * attributes to their backing store. The only supported attributes are index
+ * allocation and $MFT/$DATA. Both directory inodes and index inodes are
+ * supported for the index allocation case.
+ *
+ * The page must remain locked for the duration of the write because we apply
+ * the mst fixups, write, and then undo the fixups, so if we were to unlock the
+ * page before undoing the fixups, any other user of the page will see the
+ * page contents as corrupt.
+ *
+ * We clear the page uptodate flag for the duration of the function to ensure
+ * exclusion for the $MFT/$DATA case against someone mapping an mft record we
+ * are about to apply the mst fixups to.
+ *
+ * Return 0 on success and -errno on error.
+ *
+ * Based on ntfs_write_block(), ntfs_mft_writepage(), and
+ * write_mft_record_nolock().
+ */
+static int ntfs_write_mst_block(struct page *page,
+ struct writeback_control *wbc)
+{
+ sector_t block, dblock, rec_block;
+ struct inode *vi = page->mapping->host;
+ ntfs_inode *ni = NTFS_I(vi);
+ ntfs_volume *vol = ni->vol;
+ u8 *kaddr;
+ unsigned int rec_size = ni->itype.index.block_size;
+ ntfs_inode *locked_nis[PAGE_CACHE_SIZE / rec_size];
+ struct buffer_head *bh, *head, *tbh, *rec_start_bh;
+ struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+ runlist_element *rl;
+ int i, nr_locked_nis, nr_recs, nr_bhs, max_bhs, bhs_per_rec, err, err2;
+ unsigned bh_size, rec_size_bits;
+ BOOL sync, is_mft, page_is_dirty, rec_is_dirty;
+ unsigned char bh_size_bits;
+
+ ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
+ "0x%lx.", vi->i_ino, ni->type, page->index);
+ BUG_ON(!NInoNonResident(ni));
+ BUG_ON(!NInoMstProtected(ni));
+ is_mft = (S_ISREG(vi->i_mode) && !vi->i_ino);
+ /*
+ * NOTE: ntfs_write_mst_block() would be called for $MFTMirr if a page
+ * in its page cache were to be marked dirty. However this should
+ * never happen with the current driver and considering we do not
+ * handle this case here we do want to BUG(), at least for now.
+ */
+ BUG_ON(!(is_mft || S_ISDIR(vi->i_mode) ||
+ (NInoAttr(ni) && ni->type == AT_INDEX_ALLOCATION)));
+ bh_size = vol->sb->s_blocksize;
+ bh_size_bits = vol->sb->s_blocksize_bits;
+ max_bhs = PAGE_CACHE_SIZE / bh_size;
+ BUG_ON(!max_bhs);
+ BUG_ON(max_bhs > MAX_BUF_PER_PAGE);
+
+ /* Were we called for sync purposes? */
+ sync = (wbc->sync_mode == WB_SYNC_ALL);
+
+ /* Make sure we have mapped buffers. */
+ bh = head = page_buffers(page);
+ BUG_ON(!bh);
+
+ rec_size_bits = ni->itype.index.block_size_bits;
+ BUG_ON(!(PAGE_CACHE_SIZE >> rec_size_bits));
+ bhs_per_rec = rec_size >> bh_size_bits;
+ BUG_ON(!bhs_per_rec);
+
+ /* The first block in the page. */
+ rec_block = block = (sector_t)page->index <<
+ (PAGE_CACHE_SHIFT - bh_size_bits);
+
+ /* The first out of bounds block for the data size. */
+ dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits;
+
+ rl = NULL;
+ err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0;
+ page_is_dirty = rec_is_dirty = FALSE;
+ rec_start_bh = NULL;
+ do {
+ BOOL is_retry = FALSE;
+
+ if (likely(block < rec_block)) {
+ if (unlikely(block >= dblock)) {
+ clear_buffer_dirty(bh);
+ set_buffer_uptodate(bh);
+ continue;
+ }
+ /*
+ * This block is not the first one in the record. We
+ * ignore the buffer's dirty state because we could
+ * have raced with a parallel mark_ntfs_record_dirty().
+ */
+ if (!rec_is_dirty)
+ continue;
+ if (unlikely(err2)) {
+ if (err2 != -ENOMEM)
+ clear_buffer_dirty(bh);
+ continue;
+ }
+ } else /* if (block == rec_block) */ {
+ BUG_ON(block > rec_block);
+ /* This block is the first one in the record. */
+ rec_block += bhs_per_rec;
+ err2 = 0;
+ if (unlikely(block >= dblock)) {
+ clear_buffer_dirty(bh);
+ continue;
+ }
+ if (!buffer_dirty(bh)) {
+ /* Clean records are not written out. */
+ rec_is_dirty = FALSE;
+ continue;
+ }
+ rec_is_dirty = TRUE;
+ rec_start_bh = bh;
+ }
+ /* Need to map the buffer if it is not mapped already. */
+ if (unlikely(!buffer_mapped(bh))) {
+ VCN vcn;
+ LCN lcn;
+ unsigned int vcn_ofs;
+
+ bh->b_bdev = vol->sb->s_bdev;
+ /* Obtain the vcn and offset of the current block. */
+ vcn = (VCN)block << bh_size_bits;
+ vcn_ofs = vcn & vol->cluster_size_mask;
+ vcn >>= vol->cluster_size_bits;
+ if (!rl) {
+lock_retry_remap:
+ down_read(&ni->runlist.lock);
+ rl = ni->runlist.rl;
+ }
+ if (likely(rl != NULL)) {
+ /* Seek to element containing target vcn. */
+ while (rl->length && rl[1].vcn <= vcn)
+ rl++;
+ lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
+ } else
+ lcn = LCN_RL_NOT_MAPPED;
+ /* Successful remap. */
+ if (likely(lcn >= 0)) {
+ /* Setup buffer head to correct block. */
+ bh->b_blocknr = ((lcn <<
+ vol->cluster_size_bits) +
+ vcn_ofs) >> bh_size_bits;
+ set_buffer_mapped(bh);
+ } else {
+ /*
+ * Remap failed. Retry to map the runlist once
+ * unless we are working on $MFT which always
+ * has the whole of its runlist in memory.
+ */
+ if (!is_mft && !is_retry &&
+ lcn == LCN_RL_NOT_MAPPED) {
+ is_retry = TRUE;
+ /*
+ * Attempt to map runlist, dropping
+ * lock for the duration.
+ */
+ up_read(&ni->runlist.lock);
+ err2 = ntfs_map_runlist(ni, vcn);
+ if (likely(!err2))
+ goto lock_retry_remap;
+ if (err2 == -ENOMEM)
+ page_is_dirty = TRUE;
+ lcn = err2;
+ } else {
+ err2 = -EIO;
+ if (!rl)
+ up_read(&ni->runlist.lock);
+ }
+ /* Hard error. Abort writing this record. */
+ if (!err || err == -ENOMEM)
+ err = err2;
+ bh->b_blocknr = -1;
+ ntfs_error(vol->sb, "Cannot write ntfs record "
+ "0x%llx (inode 0x%lx, "
+ "attribute type 0x%x) because "
+ "its location on disk could "
+ "not be determined (error "
+ "code %lli).",
+ (long long)block <<
+ bh_size_bits >>
+ vol->mft_record_size_bits,
+ ni->mft_no, ni->type,
+ (long long)lcn);
+ /*
+ * If this is not the first buffer, remove the
+ * buffers in this record from the list of
+ * buffers to write and clear their dirty bit
+ * if not error -ENOMEM.
+ */
+ if (rec_start_bh != bh) {
+ while (bhs[--nr_bhs] != rec_start_bh)
+ ;
+ if (err2 != -ENOMEM) {
+ do {
+ clear_buffer_dirty(
+ rec_start_bh);
+ } while ((rec_start_bh =
+ rec_start_bh->
+ b_this_page) !=
+ bh);
+ }
+ }
+ continue;
+ }
+ }
+ BUG_ON(!buffer_uptodate(bh));
+ BUG_ON(nr_bhs >= max_bhs);
+ bhs[nr_bhs++] = bh;
+ } while (block++, (bh = bh->b_this_page) != head);
+ if (unlikely(rl))
+ up_read(&ni->runlist.lock);
+ /* If there were no dirty buffers, we are done. */
+ if (!nr_bhs)
+ goto done;
+ /* Map the page so we can access its contents. */
+ kaddr = kmap(page);
+ /* Clear the page uptodate flag whilst the mst fixups are applied. */
+ BUG_ON(!PageUptodate(page));
+ ClearPageUptodate(page);
+ for (i = 0; i < nr_bhs; i++) {
+ unsigned int ofs;
+
+ /* Skip buffers which are not at the beginning of records. */
+ if (i % bhs_per_rec)
+ continue;
+ tbh = bhs[i];
+ ofs = bh_offset(tbh);
+ if (is_mft) {
+ ntfs_inode *tni;
+ unsigned long mft_no;
+
+ /* Get the mft record number. */
+ mft_no = (((s64)page->index << PAGE_CACHE_SHIFT) + ofs)
+ >> rec_size_bits;
+ /* Check whether to write this mft record. */
+ tni = NULL;
+ if (!ntfs_may_write_mft_record(vol, mft_no,
+ (MFT_RECORD*)(kaddr + ofs), &tni)) {
+ /*
+ * The record should not be written. This
+ * means we need to redirty the page before
+ * returning.
+ */
+ page_is_dirty = TRUE;
+ /*
+ * Remove the buffers in this mft record from
+ * the list of buffers to write.
+ */
+ do {
+ bhs[i] = NULL;
+ } while (++i % bhs_per_rec);
+ continue;
+ }
+ /*
+ * The record should be written. If a locked ntfs
+ * inode was returned, add it to the array of locked
+ * ntfs inodes.
+ */
+ if (tni)
+ locked_nis[nr_locked_nis++] = tni;
+ }
+ /* Apply the mst protection fixups. */
+ err2 = pre_write_mst_fixup((NTFS_RECORD*)(kaddr + ofs),
+ rec_size);
+ if (unlikely(err2)) {
+ if (!err || err == -ENOMEM)
+ err = -EIO;
+ ntfs_error(vol->sb, "Failed to apply mst fixups "
+ "(inode 0x%lx, attribute type 0x%x, "
+ "page index 0x%lx, page offset 0x%x)!"
+ " Unmount and run chkdsk.", vi->i_ino,
+ ni->type, page->index, ofs);
+ /*
+ * Mark all the buffers in this record clean as we do
+ * not want to write corrupt data to disk.
+ */
+ do {
+ clear_buffer_dirty(bhs[i]);
+ bhs[i] = NULL;
+ } while (++i % bhs_per_rec);
+ continue;
+ }
+ nr_recs++;
+ }
+ /* If no records are to be written out, we are done. */
+ if (!nr_recs)
+ goto unm_done;
+ flush_dcache_page(page);
+ /* Lock buffers and start synchronous write i/o on them. */
+ for (i = 0; i < nr_bhs; i++) {
+ tbh = bhs[i];
+ if (!tbh)
+ continue;
+ if (unlikely(test_set_buffer_locked(tbh)))
+ BUG();
+ /* The buffer dirty state is now irrelevant, just clean it. */
+ clear_buffer_dirty(tbh);
+ BUG_ON(!buffer_uptodate(tbh));
+ BUG_ON(!buffer_mapped(tbh));
+ get_bh(tbh);
+ tbh->b_end_io = end_buffer_write_sync;
+ submit_bh(WRITE, tbh);
+ }
+ /* Synchronize the mft mirror now if not @sync. */
+ if (is_mft && !sync)
+ goto do_mirror;
+do_wait:
+ /* Wait on i/o completion of buffers. */
+ for (i = 0; i < nr_bhs; i++) {
+ tbh = bhs[i];
+ if (!tbh)
+ continue;
+ wait_on_buffer(tbh);
+ if (unlikely(!buffer_uptodate(tbh))) {
+ ntfs_error(vol->sb, "I/O error while writing ntfs "
+ "record buffer (inode 0x%lx, "
+ "attribute type 0x%x, page index "
+ "0x%lx, page offset 0x%lx)! Unmount "
+ "and run chkdsk.", vi->i_ino, ni->type,
+ page->index, bh_offset(tbh));
+ if (!err || err == -ENOMEM)
+ err = -EIO;
+ /*
+ * Set the buffer uptodate so the page and buffer
+ * states do not become out of sync.
+ */
+ set_buffer_uptodate(tbh);
+ }
+ }
+ /* If @sync, now synchronize the mft mirror. */
+ if (is_mft && sync) {
+do_mirror:
+ for (i = 0; i < nr_bhs; i++) {
+ unsigned long mft_no;
+ unsigned int ofs;
+
+ /*
+ * Skip buffers which are not at the beginning of
+ * records.
+ */
+ if (i % bhs_per_rec)
+ continue;
+ tbh = bhs[i];
+ /* Skip removed buffers (and hence records). */
+ if (!tbh)
+ continue;
+ ofs = bh_offset(tbh);
+ /* Get the mft record number. */
+ mft_no = (((s64)page->index << PAGE_CACHE_SHIFT) + ofs)
+ >> rec_size_bits;
+ if (mft_no < vol->mftmirr_size)
+ ntfs_sync_mft_mirror(vol, mft_no,
+ (MFT_RECORD*)(kaddr + ofs),
+ sync);
+ }
+ if (!sync)
+ goto do_wait;
+ }
+ /* Remove the mst protection fixups again. */
+ for (i = 0; i < nr_bhs; i++) {
+ if (!(i % bhs_per_rec)) {
+ tbh = bhs[i];
+ if (!tbh)
+ continue;
+ post_write_mst_fixup((NTFS_RECORD*)(kaddr +
+ bh_offset(tbh)));
+ }
+ }
+ flush_dcache_page(page);
+unm_done:
+ /* Unlock any locked inodes. */
+ while (nr_locked_nis-- > 0) {
+ ntfs_inode *tni, *base_tni;
+
+ tni = locked_nis[nr_locked_nis];
+ /* Get the base inode. */
+ mutex_lock(&tni->extent_lock);
+ if (tni->nr_extents >= 0)
+ base_tni = tni;
+ else {
+ base_tni = tni->ext.base_ntfs_ino;
+ BUG_ON(!base_tni);
+ }
+ mutex_unlock(&tni->extent_lock);
+ ntfs_debug("Unlocking %s inode 0x%lx.",
+ tni == base_tni ? "base" : "extent",
+ tni->mft_no);
+ mutex_unlock(&tni->mrec_lock);
+ atomic_dec(&tni->count);
+ iput(VFS_I(base_tni));
+ }
+ SetPageUptodate(page);
+ kunmap(page);
+done:
+ if (unlikely(err && err != -ENOMEM)) {
+ /*
+ * Set page error if there is only one ntfs record in the page.
+ * Otherwise we would loose per-record granularity.
+ */
+ if (ni->itype.index.block_size == PAGE_CACHE_SIZE)
+ SetPageError(page);
+ NVolSetErrors(vol);
+ }
+ if (page_is_dirty) {
+ ntfs_debug("Page still contains one or more dirty ntfs "
+ "records. Redirtying the page starting at "
+ "record 0x%lx.", page->index <<
+ (PAGE_CACHE_SHIFT - rec_size_bits));
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ } else {
+ /*
+ * Keep the VM happy. This must be done otherwise the
+ * radix-tree tag PAGECACHE_TAG_DIRTY remains set even though
+ * the page is clean.
+ */
+ BUG_ON(PageWriteback(page));
+ set_page_writeback(page);
+ unlock_page(page);
+ end_page_writeback(page);
+ }
+ if (likely(!err))
+ ntfs_debug("Done.");
+ return err;
+}
+
/**
* ntfs_writepage - write a @page to the backing store
* @page: page cache page to write out
+ * @wbc: writeback control structure
+ *
+ * This is called from the VM when it wants to have a dirty ntfs page cache
+ * page cleaned. The VM has already locked the page and marked it clean.
*
* For non-resident attributes, ntfs_writepage() writes the @page by calling
* the ntfs version of the generic block_write_full_page() function,
* For resident attributes, OTOH, ntfs_writepage() writes the @page by copying
* the data to the mft record (which at this stage is most likely in memory).
* The mft record is then marked dirty and written out asynchronously via the
- * vfs inode dirty code path.
- *
- * Note the caller clears the page dirty flag before calling ntfs_writepage().
+ * vfs inode dirty code path for the inode the mft record belongs to or via the
+ * vm page dirty code path for the page the mft record is in.
*
* Based on ntfs_readpage() and fs/buffer.c::block_write_full_page().
*
*/
static int ntfs_writepage(struct page *page, struct writeback_control *wbc)
{
- s64 attr_pos;
- struct inode *vi;
- ntfs_inode *ni, *base_ni;
+ loff_t i_size;
+ struct inode *vi = page->mapping->host;
+ ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
char *kaddr;
- attr_search_context *ctx;
- MFT_RECORD *m;
- u32 attr_len, bytes;
+ ntfs_attr_search_ctx *ctx = NULL;
+ MFT_RECORD *m = NULL;
+ u32 attr_len;
int err;
+retry_writepage:
BUG_ON(!PageLocked(page));
-
- vi = page->mapping->host;
-
+ i_size = i_size_read(vi);
/* Is the page fully outside i_size? (truncate in progress) */
- if (unlikely(page->index >= (vi->i_size + PAGE_CACHE_SIZE - 1) >>
+ if (unlikely(page->index >= (i_size + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT)) {
+ /*
+ * The page may have dirty, unmapped buffers. Make them
+ * freeable here, so the page does not leak.
+ */
+ block_invalidatepage(page, 0);
unlock_page(page);
ntfs_debug("Write outside i_size - truncated?");
return 0;
}
-
- ni = NTFS_I(vi);
-
- if (NInoNonResident(ni)) {
- /*
- * Only unnamed $DATA attributes can be compressed, encrypted,
- * and/or sparse.
- */
- if (ni->type == AT_DATA && !ni->name_len) {
- /* If file is encrypted, deny access, just like NT4. */
- if (NInoEncrypted(ni)) {
- unlock_page(page);
- ntfs_debug("Denying write access to encrypted "
- "file.");
- return -EACCES;
- }
- /* Compressed data streams are handled in compress.c. */
- if (NInoCompressed(ni)) {
- // TODO: Implement and replace this check with
- // return ntfs_write_compressed_block(page);
- unlock_page(page);
- ntfs_error(vi->i_sb, "Writing to compressed "
- "files is not supported yet. "
- "Sorry.");
- return -EOPNOTSUPP;
- }
- // TODO: Implement and remove this check.
- if (NInoSparse(ni)) {
- unlock_page(page);
- ntfs_error(vi->i_sb, "Writing to sparse files "
- "is not supported yet. Sorry.");
- return -EOPNOTSUPP;
- }
+ /*
+ * Only $DATA attributes can be encrypted and only unnamed $DATA
+ * attributes can be compressed. Index root can have the flags set but
+ * this means to create compressed/encrypted files, not that the
+ * attribute is compressed/encrypted. Note we need to check for
+ * AT_INDEX_ALLOCATION since this is the type of both directory and
+ * index inodes.
+ */
+ if (ni->type != AT_INDEX_ALLOCATION) {
+ /* If file is encrypted, deny access, just like NT4. */
+ if (NInoEncrypted(ni)) {
+ unlock_page(page);
+ BUG_ON(ni->type != AT_DATA);
+ ntfs_debug("Denying write access to encrypted file.");
+ return -EACCES;
}
-
+ /* Compressed data streams are handled in compress.c. */
+ if (NInoNonResident(ni) && NInoCompressed(ni)) {
+ BUG_ON(ni->type != AT_DATA);
+ BUG_ON(ni->name_len);
+ // TODO: Implement and replace this with
+ // return ntfs_write_compressed_block(page);
+ unlock_page(page);
+ ntfs_error(vi->i_sb, "Writing to compressed files is "
+ "not supported yet. Sorry.");
+ return -EOPNOTSUPP;
+ }
+ // TODO: Implement and remove this check.
+ if (NInoNonResident(ni) && NInoSparse(ni)) {
+ unlock_page(page);
+ ntfs_error(vi->i_sb, "Writing to sparse files is not "
+ "supported yet. Sorry.");
+ return -EOPNOTSUPP;
+ }
+ }
+ /* NInoNonResident() == NInoIndexAllocPresent() */
+ if (NInoNonResident(ni)) {
/* We have to zero every time due to mmap-at-end-of-file. */
- if (page->index >= (vi->i_size >> PAGE_CACHE_SHIFT)) {
+ if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) {
/* The page straddles i_size. */
- unsigned int ofs = vi->i_size & ~PAGE_CACHE_MASK;
+ unsigned int ofs = i_size & ~PAGE_CACHE_MASK;
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + ofs, 0, PAGE_CACHE_SIZE - ofs);
- flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
+ flush_dcache_page(page);
}
-
- // TODO: Implement and remove this check.
- if (NInoMstProtected(ni)) {
- unlock_page(page);
- ntfs_error(vi->i_sb, "Writing to MST protected "
- "attributes is not supported yet. "
- "Sorry.");
- return -EOPNOTSUPP;
- }
-
- /* Normal data stream. */
- return ntfs_write_block(wbc, page);
+ /* Handle mst protected attributes. */
+ if (NInoMstProtected(ni))
+ return ntfs_write_mst_block(page, wbc);
+ /* Normal, non-resident data stream. */
+ return ntfs_write_block(page, wbc);
}
-
/*
* Attribute is resident, implying it is not compressed, encrypted, or
- * mst protected.
+ * mst protected. This also means the attribute is smaller than an mft
+ * record and hence smaller than a page, so can simply return error on
+ * any pages with index above 0. Note the attribute can actually be
+ * marked compressed but if it is resident the actual data is not
+ * compressed so we are ok to ignore the compressed flag here.
*/
BUG_ON(page_has_buffers(page));
BUG_ON(!PageUptodate(page));
-
+ if (unlikely(page->index > 0)) {
+ ntfs_error(vi->i_sb, "BUG()! page->index (0x%lx) > 0. "
+ "Aborting write.", page->index);
+ BUG_ON(PageWriteback(page));
+ set_page_writeback(page);
+ unlock_page(page);
+ end_page_writeback(page);
+ return -EIO;
+ }
if (!NInoAttr(ni))
base_ni = ni;
else
base_ni = ni->ext.base_ntfs_ino;
-
/* Map, pin, and lock the mft record. */
m = map_mft_record(base_ni);
- if (unlikely(IS_ERR(m))) {
+ if (IS_ERR(m)) {
err = PTR_ERR(m);
m = NULL;
ctx = NULL;
goto err_out;
}
- ctx = get_attr_search_ctx(base_ni, m);
+ /*
+ * If a parallel write made the attribute non-resident, drop the mft
+ * record and retry the writepage.
+ */
+ if (unlikely(NInoNonResident(ni))) {
+ unmap_mft_record(base_ni);
+ goto retry_writepage;
+ }
+ ctx = ntfs_attr_get_search_ctx(base_ni, m);
if (unlikely(!ctx)) {
err = -ENOMEM;
goto err_out;
}
- if (unlikely(!lookup_attr(ni->type, ni->name, ni->name_len,
- IGNORE_CASE, 0, NULL, 0, ctx))) {
- err = -ENOENT;
- goto err_out;
- }
-
- /* Starting position of the page within the attribute value. */
- attr_pos = page->index << PAGE_CACHE_SHIFT;
-
- /* The total length of the attribute value. */
- attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
-
- if (unlikely(vi->i_size != attr_len)) {
- ntfs_error(vi->i_sb, "BUG()! i_size (0x%llx) doesn't match "
- "attr_len (0x%x). Aborting write.", vi->i_size,
- attr_len);
- err = -EIO;
- goto err_out;
- }
- if (unlikely(attr_pos >= attr_len)) {
- ntfs_error(vi->i_sb, "BUG()! attr_pos (0x%llx) > attr_len "
- "(0x%x). Aborting write.",
- (unsigned long long)attr_pos, attr_len);
- err = -EIO;
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, 0, NULL, 0, ctx);
+ if (unlikely(err))
goto err_out;
- }
-
- bytes = attr_len - attr_pos;
- if (unlikely(bytes > PAGE_CACHE_SIZE))
- bytes = PAGE_CACHE_SIZE;
-
/*
* Keep the VM happy. This must be done otherwise the radix-tree tag
* PAGECACHE_TAG_DIRTY remains set even though the page is clean.
BUG_ON(PageWriteback(page));
set_page_writeback(page);
unlock_page(page);
-
- /*
- * Here, we don't need to zero the out of bounds area everytime because
- * the below memcpy() already takes care of the mmap-at-end-of-file
- * requirements. If the file is converted to a non-resident one, then
- * the code path use is switched to the non-resident one where the
- * zeroing happens on each ntfs_writepage() invocation.
- *
- * The above also applies nicely when i_size is decreased.
- *
- * When i_size is increased, the memory between the old and new i_size
- * _must_ be zeroed (or overwritten with new data). Otherwise we will
- * expose data to userspace/disk which should never have been exposed.
- *
- * FIXME: Ensure that i_size increases do the zeroing/overwriting and
- * if we cannot guarantee that, then enable the zeroing below. If the
- * zeroing below is enabled, we MUST move the unlock_page() from above
- * to after the kunmap_atomic(), i.e. just before the
- * end_page_writeback().
- */
-
+ attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
+ i_size = i_size_read(vi);
+ if (unlikely(attr_len > i_size)) {
+ /* Race with shrinking truncate or a failed truncate. */
+ attr_len = i_size;
+ /*
+ * If the truncate failed, fix it up now. If a concurrent
+ * truncate, we do its job, so it does not have to do anything.
+ */
+ err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr,
+ attr_len);
+ /* Shrinking cannot fail. */
+ BUG_ON(err);
+ }
kaddr = kmap_atomic(page, KM_USER0);
/* Copy the data from the page to the mft record. */
- memcpy((u8*)ctx->attr + le16_to_cpu(
- ctx->attr->data.resident.value_offset) + attr_pos,
- kaddr, bytes);
- flush_dcache_mft_record_page(ctx->ntfs_ino);
-#if 0
- /* Zero out of bounds area. */
- if (likely(bytes < PAGE_CACHE_SIZE)) {
- memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
- flush_dcache_page(page);
- }
-#endif
+ memcpy((u8*)ctx->attr +
+ le16_to_cpu(ctx->attr->data.resident.value_offset),
+ kaddr, attr_len);
+ /* Zero out of bounds area in the page cache page. */
+ memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
kunmap_atomic(kaddr, KM_USER0);
-
+ flush_dcache_page(page);
+ flush_dcache_mft_record_page(ctx->ntfs_ino);
+ /* We are done with the page. */
end_page_writeback(page);
-
- /* Mark the mft record dirty, so it gets written back. */
+ /* Finally, mark the mft record dirty, so it gets written back. */
mark_mft_record_dirty(ctx->ntfs_ino);
-
- put_attr_search_ctx(ctx);
+ ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(base_ni);
return 0;
err_out:
"page so we try again later.");
/*
* Put the page back on mapping->dirty_pages, but leave its
- * buffer's dirty state as-is.
+ * buffers' dirty state as-is.
*/
redirty_page_for_writepage(wbc, page);
err = 0;
} else {
ntfs_error(vi->i_sb, "Resident attribute write failed with "
- "error %i. Setting page error flag.", -err);
+ "error %i.", err);
SetPageError(page);
+ NVolSetErrors(ni->vol);
}
unlock_page(page);
if (ctx)
- put_attr_search_ctx(ctx);
- if (m)
- unmap_mft_record(base_ni);
- return err;
-}
-
-/**
- * ntfs_prepare_nonresident_write -
- *
- */
-static int ntfs_prepare_nonresident_write(struct page *page,
- unsigned from, unsigned to)
-{
- VCN vcn;
- LCN lcn;
- sector_t block, ablock, iblock;
- struct inode *vi;
- ntfs_inode *ni;
- ntfs_volume *vol;
- run_list_element *rl;
- struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
- unsigned int vcn_ofs, block_start, block_end, blocksize;
- int err;
- BOOL is_retry;
- unsigned char blocksize_bits;
-
- vi = page->mapping->host;
- ni = NTFS_I(vi);
- vol = ni->vol;
-
- ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
- "0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
- page->index, from, to);
-
- BUG_ON(!NInoNonResident(ni));
- BUG_ON(NInoMstProtected(ni));
-
- blocksize_bits = vi->i_blkbits;
- blocksize = 1 << blocksize_bits;
-
- /*
- * create_empty_buffers() will create uptodate/dirty buffers if the
- * page is uptodate/dirty.
- */
- if (!page_has_buffers(page))
- create_empty_buffers(page, blocksize, 0);
- bh = head = page_buffers(page);
- if (unlikely(!bh))
- return -ENOMEM;
-
- /* The first block in the page. */
- block = page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
-
- /*
- * The first out of bounds block for the allocated size. No need to
- * round up as allocated_size is in multiples of cluster size and the
- * minimum cluster size is 512 bytes, which is equal to the smallest
- * blocksize.
- */
- ablock = ni->allocated_size >> blocksize_bits;
-
- /* The last (fully or partially) initialized block. */
- iblock = ni->initialized_size >> blocksize_bits;
-
- /* Loop through all the buffers in the page. */
- block_start = 0;
- rl = NULL;
- err = 0;
- do {
- block_end = block_start + blocksize;
- /*
- * If buffer @bh is outside the write, just mark it uptodate
- * if the page is uptodate and continue with the next buffer.
- */
- if (block_end <= from || block_start >= to) {
- if (PageUptodate(page)) {
- if (!buffer_uptodate(bh))
- set_buffer_uptodate(bh);
- }
- continue;
- }
- /*
- * @bh is at least partially being written to.
- * Make sure it is not marked as new.
- */
- //if (buffer_new(bh))
- // clear_buffer_new(bh);
-
- if (block >= ablock) {
- // TODO: block is above allocated_size, need to
- // allocate it. Best done in one go to accommodate not
- // only block but all above blocks up to and including:
- // ((page->index << PAGE_CACHE_SHIFT) + to + blocksize
- // - 1) >> blobksize_bits. Obviously will need to round
- // up to next cluster boundary, too. This should be
- // done with a helper function, so it can be reused.
- ntfs_error(vol->sb, "Writing beyond allocated size "
- "is not supported yet. Sorry.");
- err = -EOPNOTSUPP;
- goto err_out;
- // Need to update ablock.
- // Need to set_buffer_new() on all block bhs that are
- // newly allocated.
- }
- /*
- * Now we have enough allocated size to fulfill the whole
- * request, i.e. block < ablock is true.
- */
- if (unlikely((block >= iblock) &&
- (ni->initialized_size < vi->i_size))) {
- /*
- * If this page is fully outside initialized size, zero
- * out all pages between the current initialized size
- * and the current page. Just use ntfs_readpage() to do
- * the zeroing transparently.
- */
- if (block > iblock) {
- // TODO:
- // For each page do:
- // - read_cache_page()
- // Again for each page do:
- // - wait_on_page_locked()
- // - Check (PageUptodate(page) &&
- // !PageError(page))
- // Update initialized size in the attribute and
- // in the inode.
- // Again, for each page do:
- // __set_page_dirty_buffers();
- // page_cache_release()
- // We don't need to wait on the writes.
- // Update iblock.
- }
- /*
- * The current page straddles initialized size. Zero
- * all non-uptodate buffers and set them uptodate (and
- * dirty?). Note, there aren't any non-uptodate buffers
- * if the page is uptodate.
- * FIXME: For an uptodate page, the buffers may need to
- * be written out because they were not initialized on
- * disk before.
- */
- if (!PageUptodate(page)) {
- // TODO:
- // Zero any non-uptodate buffers up to i_size.
- // Set them uptodate and dirty.
- }
- // TODO:
- // Update initialized size in the attribute and in the
- // inode (up to i_size).
- // Update iblock.
- // FIXME: This is inefficient. Try to batch the two
- // size changes to happen in one go.
- ntfs_error(vol->sb, "Writing beyond initialized size "
- "is not supported yet. Sorry.");
- err = -EOPNOTSUPP;
- goto err_out;
- // Do NOT set_buffer_new() BUT DO clear buffer range
- // outside write request range.
- // set_buffer_uptodate() on complete buffers as well as
- // set_buffer_dirty().
- }
-
- /* Need to map unmapped buffers. */
- if (!buffer_mapped(bh)) {
- /* Unmapped buffer. Need to map it. */
- bh->b_bdev = vol->sb->s_bdev;
-
- /* Convert block into corresponding vcn and offset. */
- vcn = (VCN)block << blocksize_bits >>
- vol->cluster_size_bits;
- vcn_ofs = ((VCN)block << blocksize_bits) &
- vol->cluster_size_mask;
-
- is_retry = FALSE;
- if (!rl) {
-lock_retry_remap:
- down_read(&ni->run_list.lock);
- rl = ni->run_list.rl;
- }
- if (likely(rl != NULL)) {
- /* Seek to element containing target vcn. */
- while (rl->length && rl[1].vcn <= vcn)
- rl++;
- lcn = vcn_to_lcn(rl, vcn);
- } else
- lcn = (LCN)LCN_RL_NOT_MAPPED;
- if (unlikely(lcn < 0)) {
- /*
- * We extended the attribute allocation above.
- * If we hit an ENOENT here it means that the
- * allocation was insufficient which is a bug.
- */
- BUG_ON(lcn == LCN_ENOENT);
-
- /* It is a hole, need to instantiate it. */
- if (lcn == LCN_HOLE) {
- // TODO: Instantiate the hole.
- // clear_buffer_new(bh);
- // unmap_underlying_metadata(bh->b_bdev,
- // bh->b_blocknr);
- // For non-uptodate buffers, need to
- // zero out the region outside the
- // request in this bh or all bhs,
- // depending on what we implemented
- // above.
- // Need to flush_dcache_page().
- // Or could use set_buffer_new()
- // instead?
- ntfs_error(vol->sb, "Writing into "
- "sparse regions is "
- "not supported yet. "
- "Sorry.");
- err = -EOPNOTSUPP;
- goto err_out;
- } else if (!is_retry &&
- lcn == LCN_RL_NOT_MAPPED) {
- is_retry = TRUE;
- /*
- * Attempt to map run list, dropping
- * lock for the duration.
- */
- up_read(&ni->run_list.lock);
- err = map_run_list(ni, vcn);
- if (likely(!err))
- goto lock_retry_remap;
- rl = NULL;
- }
- /*
- * Failed to map the buffer, even after
- * retrying.
- */
- bh->b_blocknr = -1UL;
- ntfs_error(vol->sb, "vcn_to_lcn(vcn = 0x%llx) "
- "failed with error code "
- "0x%llx%s.",
- (unsigned long long)vcn,
- (unsigned long long)-lcn,
- is_retry ? " even after "
- "retrying" : "");
- // FIXME: Depending on vol->on_errors, do
- // something.
- if (!err)
- err = -EIO;
- goto err_out;
- }
- /* We now have a successful remap, i.e. lcn >= 0. */
-
- /* Setup buffer head to correct block. */
- bh->b_blocknr = ((lcn << vol->cluster_size_bits)
- + vcn_ofs) >> blocksize_bits;
- set_buffer_mapped(bh);
-
- // FIXME: Something analogous to this is needed for
- // each newly allocated block, i.e. BH_New.
- // FIXME: Might need to take this out of the
- // if (!buffer_mapped(bh)) {}, depending on how we
- // implement things during the allocated_size and
- // initialized_size extension code above.
- if (buffer_new(bh)) {
- clear_buffer_new(bh);
- unmap_underlying_metadata(bh->b_bdev,
- bh->b_blocknr);
- if (PageUptodate(page)) {
- set_buffer_uptodate(bh);
- continue;
- }
- /*
- * Page is _not_ uptodate, zero surrounding
- * region. NOTE: This is how we decide if to
- * zero or not!
- */
- if (block_end > to || block_start < from) {
- void *kaddr;
-
- kaddr = kmap_atomic(page, KM_USER0);
- if (block_end > to)
- memset(kaddr + to, 0,
- block_end - to);
- if (block_start < from)
- memset(kaddr + block_start, 0,
- from -
- block_start);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
- }
- continue;
- }
- }
- /* @bh is mapped, set it uptodate if the page is uptodate. */
- if (PageUptodate(page)) {
- if (!buffer_uptodate(bh))
- set_buffer_uptodate(bh);
- continue;
- }
- /*
- * The page is not uptodate. The buffer is mapped. If it is not
- * uptodate, and it is only partially being written to, we need
- * to read the buffer in before the write, i.e. right now.
- */
- if (!buffer_uptodate(bh) &&
- (block_start < from || block_end > to)) {
- ll_rw_block(READ, 1, &bh);
- *wait_bh++ = bh;
- }
- } while (block++, block_start = block_end,
- (bh = bh->b_this_page) != head);
-
- /* Release the lock if we took it. */
- if (rl) {
- up_read(&ni->run_list.lock);
- rl = NULL;
- }
-
- /* If we issued read requests, let them complete. */
- while (wait_bh > wait) {
- wait_on_buffer(*--wait_bh);
- if (!buffer_uptodate(*wait_bh))
- return -EIO;
- }
-
- ntfs_debug("Done.");
- return 0;
-err_out:
- /*
- * Zero out any newly allocated blocks to avoid exposing stale data.
- * If BH_New is set, we know that the block was newly allocated in the
- * above loop.
- * FIXME: What about initialized_size increments? Have we done all the
- * required zeroing above? If not this error handling is broken, and
- * in particular the if (block_end <= from) check is completely bogus.
- */
- bh = head;
- block_start = 0;
- is_retry = FALSE;
- do {
- block_end = block_start + blocksize;
- if (block_end <= from)
- continue;
- if (block_start >= to)
- break;
- if (buffer_new(bh)) {
- void *kaddr;
-
- clear_buffer_new(bh);
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + block_start, 0, bh->b_size);
- kunmap_atomic(kaddr, KM_USER0);
- set_buffer_uptodate(bh);
- mark_buffer_dirty(bh);
- is_retry = TRUE;
- }
- } while (block_start = block_end, (bh = bh->b_this_page) != head);
- if (is_retry)
- flush_dcache_page(page);
- if (rl)
- up_read(&ni->run_list.lock);
- return err;
-}
-
-/**
- * ntfs_prepare_write - prepare a page for receiving data
- *
- * This is called from generic_file_write() with i_sem held on the inode
- * (@page->mapping->host). The @page is locked and kmap()ped so page_address()
- * can simply be used. The source data has not yet been copied into the @page.
- *
- * Need to extend the attribute/fill in holes if necessary, create blocks and
- * make partially overwritten blocks uptodate,
- *
- * i_size is not to be modified yet.
- *
- * Return 0 on success or -errno on error.
- *
- * Should be using block_prepare_write() [support for sparse files] or
- * cont_prepare_write() [no support for sparse files]. Can't do that due to
- * ntfs specifics but can look at them for implementation guidancea.
- *
- * Note: In the range, @from is inclusive and @to is exclusive, i.e. @from is
- * the first byte in the page that will be written to and @to is the first byte
- * after the last byte that will be written to.
- */
-static int ntfs_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
-{
- struct inode *vi = page->mapping->host;
- ntfs_inode *ni = NTFS_I(vi);
-
- ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
- "0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
- page->index, from, to);
-
- BUG_ON(!PageLocked(page));
- BUG_ON(from > PAGE_CACHE_SIZE);
- BUG_ON(to > PAGE_CACHE_SIZE);
- BUG_ON(from > to);
-
- if (NInoNonResident(ni)) {
- /*
- * Only unnamed $DATA attributes can be compressed, encrypted,
- * and/or sparse.
- */
- if (ni->type == AT_DATA && !ni->name_len) {
- /* If file is encrypted, deny access, just like NT4. */
- if (NInoEncrypted(ni)) {
- ntfs_debug("Denying write access to encrypted "
- "file.");
- return -EACCES;
- }
- /* Compressed data streams are handled in compress.c. */
- if (NInoCompressed(ni)) {
- // TODO: Implement and replace this check with
- // return ntfs_write_compressed_block(page);
- ntfs_error(vi->i_sb, "Writing to compressed "
- "files is not supported yet. "
- "Sorry.");
- return -EOPNOTSUPP;
- }
- // TODO: Implement and remove this check.
- if (NInoSparse(ni)) {
- ntfs_error(vi->i_sb, "Writing to sparse files "
- "is not supported yet. Sorry.");
- return -EOPNOTSUPP;
- }
- }
-
- // TODO: Implement and remove this check.
- if (NInoMstProtected(ni)) {
- ntfs_error(vi->i_sb, "Writing to MST protected "
- "attributes is not supported yet. "
- "Sorry.");
- return -EOPNOTSUPP;
- }
-
- /* Normal data stream. */
- return ntfs_prepare_nonresident_write(page, from, to);
- }
-
- /*
- * Attribute is resident, implying it is not compressed, encrypted, or
- * mst protected.
- */
- BUG_ON(page_has_buffers(page));
-
- /* Do we need to resize the attribute? */
- if (((s64)page->index << PAGE_CACHE_SHIFT) + to > vi->i_size) {
- // TODO: Implement resize...
- ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
- "not supported yet. Sorry.");
- return -EOPNOTSUPP;
- }
-
- /*
- * Because resident attributes are handled by memcpy() to/from the
- * corresponding MFT record, and because this form of i/o is byte
- * aligned rather than block aligned, there is no need to bring the
- * page uptodate here as in the non-resident case where we need to
- * bring the buffers straddled by the write uptodate before
- * generic_file_write() does the copying from userspace.
- *
- * We thus defer the uptodate bringing of the page region outside the
- * region written to to ntfs_commit_write(). The reason for doing this
- * is that we save one round of:
- * map_mft_record(), get_attr_search_ctx(), lookup_attr(),
- * kmap_atomic(), kunmap_atomic(), put_attr_search_ctx(),
- * unmap_mft_record().
- * Which is obviously a very worthwhile save.
- *
- * Thus we just return success now...
- */
- ntfs_debug("Done.");
- return 0;
-}
-
-/*
- * NOTES: There is a disparity between the apparent need to extend the
- * attribute in prepare write but to update i_size only in commit write.
- * Need to make sure i_sem protection is sufficient. And if not will need to
- * handle this in some way or another.
- */
-
-/**
- * ntfs_commit_nonresident_write -
- *
- */
-static int ntfs_commit_nonresident_write(struct page *page,
- unsigned from, unsigned to)
-{
- s64 pos = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
- struct inode *vi;
- struct buffer_head *bh, *head;
- unsigned int block_start, block_end, blocksize;
- BOOL partial;
-
- vi = page->mapping->host;
-
- ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
- "0x%lx, from = %u, to = %u.", vi->i_ino,
- NTFS_I(vi)->type, page->index, from, to);
-
- blocksize = 1 << vi->i_blkbits;
-
- // FIXME: We need a whole slew of special cases in here for MST
- // protected attributes for example. For compressed files, too...
- // For now, we know ntfs_prepare_write() would have failed so we can't
- // get here in any of the cases which we have to special case, so we
- // are just a ripped off unrolled generic_commit_write() at present.
-
- bh = head = page_buffers(page);
- block_start = 0;
- partial = FALSE;
- do {
- block_end = block_start + blocksize;
- if (block_end <= from || block_start >= to) {
- if (!buffer_uptodate(bh))
- partial = TRUE;
- } else {
- set_buffer_uptodate(bh);
- mark_buffer_dirty(bh);
- }
- } while (block_start = block_end, (bh = bh->b_this_page) != head);
-
- /*
- * If this is a partial write which happened to make all buffers
- * uptodate then we can optimize away a bogus ->readpage() for the next
- * read(). Here we 'discover' whether the page went uptodate as a
- * result of this (potentially partial) write.
- */
- if (!partial)
- SetPageUptodate(page);
-
- /*
- * Not convinced about this at all. See disparity comment above. For
- * now we know ntfs_prepare_write() would have failed in the write
- * exceeds i_size case, so this will never trigger which is fine.
- */
- if (pos > vi->i_size) {
- ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
- "not supported yet. Sorry.");
- return -EOPNOTSUPP;
- // vi->i_size = pos;
- // mark_inode_dirty(vi);
- }
- ntfs_debug("Done.");
- return 0;
-}
-
-/**
- * ntfs_commit_write - commit the received data
- *
- * This is called from generic_file_write() with i_sem held on the inode
- * (@page->mapping->host). The @page is locked and kmap()ped so page_address()
- * can simply be used. The source data has already been copied into the @page.
- *
- * Need to mark modified blocks dirty so they get written out later when
- * ntfs_writepage() is invoked by the VM.
- *
- * Return 0 on success or -errno on error.
- *
- * Should be using generic_commit_write(). This marks buffers uptodate and
- * dirty, sets the page uptodate if all buffers in the page are uptodate, and
- * updates i_size if the end of io is beyond i_size. In that case, it also
- * marks the inode dirty. - We could still use this (obviously except for
- * NInoMstProtected() attributes, where we will need to duplicate the core code
- * because we need our own async_io completion handler) but we could just do
- * the i_size update in prepare write, when we resize the attribute. Then
- * we would avoid the i_size update and mark_inode_dirty() happening here.
- *
- * Can't use generic_commit_write() due to ntfs specialities but can look at
- * it for implementation guidance.
- *
- * If things have gone as outlined in ntfs_prepare_write(), then we do not
- * need to do any page content modifications here at all, except in the write
- * to resident attribute case, where we need to do the uptodate bringing here
- * which we combine with the copying into the mft record which means we only
- * need to map the mft record and find the attribute record in it only once.
- */
-static int ntfs_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
-{
- s64 attr_pos;
- struct inode *vi;
- ntfs_inode *ni, *base_ni;
- char *kaddr, *kattr;
- attr_search_context *ctx;
- MFT_RECORD *m;
- u32 attr_len, bytes;
- int err;
-
- vi = page->mapping->host;
- ni = NTFS_I(vi);
-
- ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
- "0x%lx, from = %u, to = %u.", vi->i_ino, ni->type,
- page->index, from, to);
-
- if (NInoNonResident(ni)) {
- /*
- * Only unnamed $DATA attributes can be compressed, encrypted,
- * and/or sparse.
- */
- if (ni->type == AT_DATA && !ni->name_len) {
- /* If file is encrypted, deny access, just like NT4. */
- if (NInoEncrypted(ni)) {
- // Should never get here!
- ntfs_debug("Denying write access to encrypted "
- "file.");
- return -EACCES;
- }
- /* Compressed data streams are handled in compress.c. */
- if (NInoCompressed(ni)) {
- // TODO: Implement and replace this check with
- // return ntfs_write_compressed_block(page);
- // Should never get here!
- ntfs_error(vi->i_sb, "Writing to compressed "
- "files is not supported yet. "
- "Sorry.");
- return -EOPNOTSUPP;
- }
- // TODO: Implement and remove this check.
- if (NInoSparse(ni)) {
- // Should never get here!
- ntfs_error(vi->i_sb, "Writing to sparse files "
- "is not supported yet. Sorry.");
- return -EOPNOTSUPP;
- }
- }
-
- // TODO: Implement and remove this check.
- if (NInoMstProtected(ni)) {
- // Should never get here!
- ntfs_error(vi->i_sb, "Writing to MST protected "
- "attributes is not supported yet. "
- "Sorry.");
- return -EOPNOTSUPP;
- }
-
- /* Normal data stream. */
- return ntfs_commit_nonresident_write(page, from, to);
- }
-
- /*
- * Attribute is resident, implying it is not compressed, encrypted, or
- * mst protected.
- */
-
- /* Do we need to resize the attribute? */
- if (((s64)page->index << PAGE_CACHE_SHIFT) + to > vi->i_size) {
- // TODO: Implement resize...
- // pos = ((s64)page->index << PAGE_CACHE_SHIFT) + to;
- // vi->i_size = pos;
- // mark_inode_dirty(vi);
- // Should never get here!
- ntfs_error(vi->i_sb, "Writing beyond the existing file size is "
- "not supported yet. Sorry.");
- return -EOPNOTSUPP;
- }
-
- if (!NInoAttr(ni))
- base_ni = ni;
- else
- base_ni = ni->ext.base_ntfs_ino;
-
- /* Map, pin, and lock the mft record. */
- m = map_mft_record(base_ni);
- if (unlikely(IS_ERR(m))) {
- err = PTR_ERR(m);
- m = NULL;
- ctx = NULL;
- goto err_out;
- }
- ctx = get_attr_search_ctx(base_ni, m);
- if (unlikely(!ctx)) {
- err = -ENOMEM;
- goto err_out;
- }
- if (unlikely(!lookup_attr(ni->type, ni->name, ni->name_len,
- IGNORE_CASE, 0, NULL, 0, ctx))) {
- err = -ENOENT;
- goto err_out;
- }
-
- /* Starting position of the page within the attribute value. */
- attr_pos = page->index << PAGE_CACHE_SHIFT;
-
- /* The total length of the attribute value. */
- attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
-
- if (unlikely(vi->i_size != attr_len)) {
- ntfs_error(vi->i_sb, "BUG()! i_size (0x%llx) doesn't match "
- "attr_len (0x%x). Aborting write.", vi->i_size,
- attr_len);
- err = -EIO;
- goto err_out;
- }
- if (unlikely(attr_pos >= attr_len)) {
- ntfs_error(vi->i_sb, "BUG()! attr_pos (0x%llx) > attr_len "
- "(0x%x). Aborting write.",
- (unsigned long long)attr_pos, attr_len);
- err = -EIO;
- goto err_out;
- }
-
- bytes = attr_len - attr_pos;
- if (unlikely(bytes > PAGE_CACHE_SIZE))
- bytes = PAGE_CACHE_SIZE;
-
- /*
- * Calculate the address of the attribute value corresponding to the
- * beginning of the current data @page.
- */
- kattr = (u8*)ctx->attr + le16_to_cpu(
- ctx->attr->data.resident.value_offset) + attr_pos;
-
- kaddr = kmap_atomic(page, KM_USER0);
-
- /* Copy the received data from the page to the mft record. */
- memcpy(kattr + from, kaddr + from, to - from);
- flush_dcache_mft_record_page(ctx->ntfs_ino);
-
- if (!PageUptodate(page)) {
- /*
- * Bring the out of bounds area(s) uptodate by copying data
- * from the mft record to the page.
- */
- if (from > 0)
- memcpy(kaddr, kattr, from);
- if (to < bytes)
- memcpy(kaddr + to, kattr + to, bytes - to);
-
- /* Zero the region outside the end of the attribute value. */
- if (likely(bytes < PAGE_CACHE_SIZE))
- memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
-
- /*
- * The probability of not having done any of the above is
- * extremely small, so we just flush unconditionally.
- */
- flush_dcache_page(page);
- SetPageUptodate(page);
- }
- kunmap_atomic(kaddr, KM_USER0);
-
- /* Mark the mft record dirty, so it gets written back. */
- mark_mft_record_dirty(ctx->ntfs_ino);
-
- put_attr_search_ctx(ctx);
- unmap_mft_record(base_ni);
- ntfs_debug("Done.");
- return 0;
-err_out:
- if (err == -ENOMEM) {
- ntfs_warning(vi->i_sb, "Error allocating memory required to "
- "commit the write.");
- if (PageUptodate(page)) {
- ntfs_warning(vi->i_sb, "Page is uptodate, setting "
- "dirty so the write will be retried "
- "later on by the VM.");
- /*
- * Put the page on mapping->dirty_pages, but leave its
- * buffer's dirty state as-is.
- */
- __set_page_dirty_nobuffers(page);
- err = 0;
- } else
- ntfs_error(vi->i_sb, "Page is not uptodate. Written "
- "data has been lost. )-:");
- } else {
- ntfs_error(vi->i_sb, "Resident attribute write failed with "
- "error %i. Setting page error flag.", -err);
- SetPageError(page);
- }
- if (ctx)
- put_attr_search_ctx(ctx);
+ ntfs_attr_put_search_ctx(ctx);
if (m)
unmap_mft_record(base_ni);
return err;
disk request queue. */
#ifdef NTFS_RW
.writepage = ntfs_writepage, /* Write dirty page to disk. */
- .prepare_write = ntfs_prepare_write, /* Prepare page and buffers
- ready to receive data. */
- .commit_write = ntfs_commit_write, /* Commit received data. */
-#endif
+#endif /* NTFS_RW */
+ .migratepage = buffer_migrate_page, /* Move a page cache page from
+ one physical page to an
+ other. */
};
/**
.readpage = ntfs_readpage, /* Fill page with data. */
.sync_page = block_sync_page, /* Currently, just unplugs the
disk request queue. */
+#ifdef NTFS_RW
+ .writepage = ntfs_writepage, /* Write dirty page to disk. */
+ .set_page_dirty = __set_page_dirty_nobuffers, /* Set the page dirty
+ without touching the buffers
+ belonging to the page. */
+#endif /* NTFS_RW */
+ .migratepage = buffer_migrate_page, /* Move a page cache page from
+ one physical page to an
+ other. */
};
+
+#ifdef NTFS_RW
+
+/**
+ * mark_ntfs_record_dirty - mark an ntfs record dirty
+ * @page: page containing the ntfs record to mark dirty
+ * @ofs: byte offset within @page at which the ntfs record begins
+ *
+ * Set the buffers and the page in which the ntfs record is located dirty.
+ *
+ * The latter also marks the vfs inode the ntfs record belongs to dirty
+ * (I_DIRTY_PAGES only).
+ *
+ * If the page does not have buffers, we create them and set them uptodate.
+ * The page may not be locked which is why we need to handle the buffers under
+ * the mapping->private_lock. Once the buffers are marked dirty we no longer
+ * need the lock since try_to_free_buffers() does not free dirty buffers.
+ */
+void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) {
+ struct address_space *mapping = page->mapping;
+ ntfs_inode *ni = NTFS_I(mapping->host);
+ struct buffer_head *bh, *head, *buffers_to_free = NULL;
+ unsigned int end, bh_size, bh_ofs;
+
+ BUG_ON(!PageUptodate(page));
+ end = ofs + ni->itype.index.block_size;
+ bh_size = VFS_I(ni)->i_sb->s_blocksize;
+ spin_lock(&mapping->private_lock);
+ if (unlikely(!page_has_buffers(page))) {
+ spin_unlock(&mapping->private_lock);
+ bh = head = alloc_page_buffers(page, bh_size, 1);
+ spin_lock(&mapping->private_lock);
+ if (likely(!page_has_buffers(page))) {
+ struct buffer_head *tail;
+
+ do {
+ set_buffer_uptodate(bh);
+ tail = bh;
+ bh = bh->b_this_page;
+ } while (bh);
+ tail->b_this_page = head;
+ attach_page_buffers(page, head);
+ } else
+ buffers_to_free = bh;
+ }
+ bh = head = page_buffers(page);
+ BUG_ON(!bh);
+ do {
+ bh_ofs = bh_offset(bh);
+ if (bh_ofs + bh_size <= ofs)
+ continue;
+ if (unlikely(bh_ofs >= end))
+ break;
+ set_buffer_dirty(bh);
+ } while ((bh = bh->b_this_page) != head);
+ spin_unlock(&mapping->private_lock);
+ __set_page_dirty_nobuffers(page);
+ if (unlikely(buffers_to_free)) {
+ do {
+ bh = buffers_to_free->b_this_page;
+ free_buffer_head(buffers_to_free);
+ buffers_to_free = bh;
+ } while (buffers_to_free);
+ }
+}
+
+#endif /* NTFS_RW */
git://git.onelab.eu / linux-2.6.git / blobdiff