| /* |
| * file.c - NTFS kernel file operations. Part of the Linux-NTFS project. |
| * |
| * Copyright (c) 2001-2006 Anton Altaparmakov |
| * |
| * This program/include file is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as published |
| * by the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program/include file is distributed in the hope that it will be |
| * useful, but WITHOUT ANY WARRANTY; without even the implied warranty |
| * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program (in the main directory of the Linux-NTFS |
| * distribution in the file COPYING); if not, write to the Free Software |
| * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include <linux/buffer_head.h> |
| #include <linux/pagemap.h> |
| #include <linux/pagevec.h> |
| #include <linux/sched.h> |
| #include <linux/swap.h> |
| #include <linux/uio.h> |
| #include <linux/writeback.h> |
| |
| #include <asm/page.h> |
| #include <asm/uaccess.h> |
| |
| #include "attrib.h" |
| #include "bitmap.h" |
| #include "inode.h" |
| #include "debug.h" |
| #include "lcnalloc.h" |
| #include "malloc.h" |
| #include "mft.h" |
| #include "ntfs.h" |
| |
| /** |
| * ntfs_file_open - called when an inode is about to be opened |
| * @vi: inode to be opened |
| * @filp: file structure describing the inode |
| * |
| * Limit file size to the page cache limit on architectures where unsigned long |
| * is 32-bits. This is the most we can do for now without overflowing the page |
| * cache page index. Doing it this way means we don't run into problems because |
| * of existing too large files. It would be better to allow the user to read |
| * the beginning of the file but I doubt very much anyone is going to hit this |
| * check on a 32-bit architecture, so there is no point in adding the extra |
| * complexity required to support this. |
| * |
| * On 64-bit architectures, the check is hopefully optimized away by the |
| * compiler. |
| * |
| * After the check passes, just call generic_file_open() to do its work. |
| */ |
| static int ntfs_file_open(struct inode *vi, struct file *filp) |
| { |
| if (sizeof(unsigned long) < 8) { |
| if (i_size_read(vi) > MAX_LFS_FILESIZE) |
| return -EFBIG; |
| } |
| return generic_file_open(vi, filp); |
| } |
| |
| #ifdef NTFS_RW |
| |
| /** |
| * ntfs_attr_extend_initialized - extend the initialized size of an attribute |
| * @ni: ntfs inode of the attribute to extend |
| * @new_init_size: requested new initialized size in bytes |
| * @cached_page: store any allocated but unused page here |
| * @lru_pvec: lru-buffering pagevec of the caller |
| * |
| * Extend the initialized size of an attribute described by the ntfs inode @ni |
| * to @new_init_size bytes. This involves zeroing any non-sparse space between |
| * the old initialized size and @new_init_size both in the page cache and on |
| * disk (if relevant complete pages are already uptodate in the page cache then |
| * these are simply marked dirty). |
| * |
| * As a side-effect, the file size (vfs inode->i_size) may be incremented as, |
| * in the resident attribute case, it is tied to the initialized size and, in |
| * the non-resident attribute case, it may not fall below the initialized size. |
| * |
| * Note that if the attribute is resident, we do not need to touch the page |
| * cache at all. This is because if the page cache page is not uptodate we |
| * bring it uptodate later, when doing the write to the mft record since we |
| * then already have the page mapped. And if the page is uptodate, the |
| * non-initialized region will already have been zeroed when the page was |
| * brought uptodate and the region may in fact already have been overwritten |
| * with new data via mmap() based writes, so we cannot just zero it. And since |
| * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped |
| * is unspecified, we choose not to do zeroing and thus we do not need to touch |
| * the page at all. For a more detailed explanation see ntfs_truncate() in |
| * fs/ntfs/inode.c. |
| * |
| * @cached_page and @lru_pvec are just optimizations for dealing with multiple |
| * pages. |
| * |
| * Return 0 on success and -errno on error. In the case that an error is |
| * encountered it is possible that the initialized size will already have been |
| * incremented some way towards @new_init_size but it is guaranteed that if |
| * this is the case, the necessary zeroing will also have happened and that all |
| * metadata is self-consistent. |
| * |
| * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be |
| * held by the caller. |
| */ |
| static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size, |
| struct page **cached_page, struct pagevec *lru_pvec) |
| { |
| s64 old_init_size; |
| loff_t old_i_size; |
| pgoff_t index, end_index; |
| unsigned long flags; |
| struct inode *vi = VFS_I(ni); |
| ntfs_inode *base_ni; |
| MFT_RECORD *m = NULL; |
| ATTR_RECORD *a; |
| ntfs_attr_search_ctx *ctx = NULL; |
| struct address_space *mapping; |
| struct page *page = NULL; |
| u8 *kattr; |
| int err; |
| u32 attr_len; |
| |
| read_lock_irqsave(&ni->size_lock, flags); |
| old_init_size = ni->initialized_size; |
| old_i_size = i_size_read(vi); |
| BUG_ON(new_init_size > ni->allocated_size); |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, " |
| "old_initialized_size 0x%llx, " |
| "new_initialized_size 0x%llx, i_size 0x%llx.", |
| vi->i_ino, (unsigned)le32_to_cpu(ni->type), |
| (unsigned long long)old_init_size, |
| (unsigned long long)new_init_size, old_i_size); |
| if (!NInoAttr(ni)) |
| base_ni = ni; |
| else |
| base_ni = ni->ext.base_ntfs_ino; |
| /* Use goto to reduce indentation and we need the label below anyway. */ |
| if (NInoNonResident(ni)) |
| goto do_non_resident_extend; |
| BUG_ON(old_init_size != old_i_size); |
| m = map_mft_record(base_ni); |
| if (IS_ERR(m)) { |
| err = PTR_ERR(m); |
| m = NULL; |
| goto err_out; |
| } |
| ctx = ntfs_attr_get_search_ctx(base_ni, m); |
| if (unlikely(!ctx)) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, 0, NULL, 0, ctx); |
| if (unlikely(err)) { |
| if (err == -ENOENT) |
| err = -EIO; |
| goto err_out; |
| } |
| m = ctx->mrec; |
| a = ctx->attr; |
| BUG_ON(a->non_resident); |
| /* The total length of the attribute value. */ |
| attr_len = le32_to_cpu(a->data.resident.value_length); |
| BUG_ON(old_i_size != (loff_t)attr_len); |
| /* |
| * Do the zeroing in the mft record and update the attribute size in |
| * the mft record. |
| */ |
| kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); |
| memset(kattr + attr_len, 0, new_init_size - attr_len); |
| a->data.resident.value_length = cpu_to_le32((u32)new_init_size); |
| /* Finally, update the sizes in the vfs and ntfs inodes. */ |
| write_lock_irqsave(&ni->size_lock, flags); |
| i_size_write(vi, new_init_size); |
| ni->initialized_size = new_init_size; |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| goto done; |
| do_non_resident_extend: |
| /* |
| * If the new initialized size @new_init_size exceeds the current file |
| * size (vfs inode->i_size), we need to extend the file size to the |
| * new initialized size. |
| */ |
| if (new_init_size > old_i_size) { |
| m = map_mft_record(base_ni); |
| if (IS_ERR(m)) { |
| err = PTR_ERR(m); |
| m = NULL; |
| goto err_out; |
| } |
| ctx = ntfs_attr_get_search_ctx(base_ni, m); |
| if (unlikely(!ctx)) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, 0, NULL, 0, ctx); |
| if (unlikely(err)) { |
| if (err == -ENOENT) |
| err = -EIO; |
| goto err_out; |
| } |
| m = ctx->mrec; |
| a = ctx->attr; |
| BUG_ON(!a->non_resident); |
| BUG_ON(old_i_size != (loff_t) |
| sle64_to_cpu(a->data.non_resident.data_size)); |
| a->data.non_resident.data_size = cpu_to_sle64(new_init_size); |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| /* Update the file size in the vfs inode. */ |
| i_size_write(vi, new_init_size); |
| ntfs_attr_put_search_ctx(ctx); |
| ctx = NULL; |
| unmap_mft_record(base_ni); |
| m = NULL; |
| } |
| mapping = vi->i_mapping; |
| index = old_init_size >> PAGE_CACHE_SHIFT; |
| end_index = (new_init_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| do { |
| /* |
| * Read the page. If the page is not present, this will zero |
| * the uninitialized regions for us. |
| */ |
| page = read_mapping_page(mapping, index, NULL); |
| if (IS_ERR(page)) { |
| err = PTR_ERR(page); |
| goto init_err_out; |
| } |
| wait_on_page_locked(page); |
| if (unlikely(!PageUptodate(page) || PageError(page))) { |
| page_cache_release(page); |
| err = -EIO; |
| goto init_err_out; |
| } |
| /* |
| * Update the initialized size in the ntfs inode. This is |
| * enough to make ntfs_writepage() work. |
| */ |
| write_lock_irqsave(&ni->size_lock, flags); |
| ni->initialized_size = (s64)(index + 1) << PAGE_CACHE_SHIFT; |
| if (ni->initialized_size > new_init_size) |
| ni->initialized_size = new_init_size; |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| /* Set the page dirty so it gets written out. */ |
| set_page_dirty(page); |
| page_cache_release(page); |
| /* |
| * Play nice with the vm and the rest of the system. This is |
| * very much needed as we can potentially be modifying the |
| * initialised size from a very small value to a really huge |
| * value, e.g. |
| * f = open(somefile, O_TRUNC); |
| * truncate(f, 10GiB); |
| * seek(f, 10GiB); |
| * write(f, 1); |
| * And this would mean we would be marking dirty hundreds of |
| * thousands of pages or as in the above example more than |
| * two and a half million pages! |
| * |
| * TODO: For sparse pages could optimize this workload by using |
| * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This |
| * would be set in readpage for sparse pages and here we would |
| * not need to mark dirty any pages which have this bit set. |
| * The only caveat is that we have to clear the bit everywhere |
| * where we allocate any clusters that lie in the page or that |
| * contain the page. |
| * |
| * TODO: An even greater optimization would be for us to only |
| * call readpage() on pages which are not in sparse regions as |
| * determined from the runlist. This would greatly reduce the |
| * number of pages we read and make dirty in the case of sparse |
| * files. |
| */ |
| balance_dirty_pages_ratelimited(mapping); |
| cond_resched(); |
| } while (++index < end_index); |
| read_lock_irqsave(&ni->size_lock, flags); |
| BUG_ON(ni->initialized_size != new_init_size); |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| /* Now bring in sync the initialized_size in the mft record. */ |
| m = map_mft_record(base_ni); |
| if (IS_ERR(m)) { |
| err = PTR_ERR(m); |
| m = NULL; |
| goto init_err_out; |
| } |
| ctx = ntfs_attr_get_search_ctx(base_ni, m); |
| if (unlikely(!ctx)) { |
| err = -ENOMEM; |
| goto init_err_out; |
| } |
| err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, 0, NULL, 0, ctx); |
| if (unlikely(err)) { |
| if (err == -ENOENT) |
| err = -EIO; |
| goto init_err_out; |
| } |
| m = ctx->mrec; |
| a = ctx->attr; |
| BUG_ON(!a->non_resident); |
| a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size); |
| done: |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| if (ctx) |
| ntfs_attr_put_search_ctx(ctx); |
| if (m) |
| unmap_mft_record(base_ni); |
| ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.", |
| (unsigned long long)new_init_size, i_size_read(vi)); |
| return 0; |
| init_err_out: |
| write_lock_irqsave(&ni->size_lock, flags); |
| ni->initialized_size = old_init_size; |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| err_out: |
| if (ctx) |
| ntfs_attr_put_search_ctx(ctx); |
| if (m) |
| unmap_mft_record(base_ni); |
| ntfs_debug("Failed. Returning error code %i.", err); |
| return err; |
| } |
| |
| /** |
| * ntfs_fault_in_pages_readable - |
| * |
| * Fault a number of userspace pages into pagetables. |
| * |
| * Unlike include/linux/pagemap.h::fault_in_pages_readable(), this one copes |
| * with more than two userspace pages as well as handling the single page case |
| * elegantly. |
| * |
| * If you find this difficult to understand, then think of the while loop being |
| * the following code, except that we do without the integer variable ret: |
| * |
| * do { |
| * ret = __get_user(c, uaddr); |
| * uaddr += PAGE_SIZE; |
| * } while (!ret && uaddr < end); |
| * |
| * Note, the final __get_user() may well run out-of-bounds of the user buffer, |
| * but _not_ out-of-bounds of the page the user buffer belongs to, and since |
| * this is only a read and not a write, and since it is still in the same page, |
| * it should not matter and this makes the code much simpler. |
| */ |
| static inline void ntfs_fault_in_pages_readable(const char __user *uaddr, |
| int bytes) |
| { |
| const char __user *end; |
| volatile char c; |
| |
| /* Set @end to the first byte outside the last page we care about. */ |
| end = (const char __user*)PAGE_ALIGN((ptrdiff_t __user)uaddr + bytes); |
| |
| while (!__get_user(c, uaddr) && (uaddr += PAGE_SIZE, uaddr < end)) |
| ; |
| } |
| |
| /** |
| * ntfs_fault_in_pages_readable_iovec - |
| * |
| * Same as ntfs_fault_in_pages_readable() but operates on an array of iovecs. |
| */ |
| static inline void ntfs_fault_in_pages_readable_iovec(const struct iovec *iov, |
| size_t iov_ofs, int bytes) |
| { |
| do { |
| const char __user *buf; |
| unsigned len; |
| |
| buf = iov->iov_base + iov_ofs; |
| len = iov->iov_len - iov_ofs; |
| if (len > bytes) |
| len = bytes; |
| ntfs_fault_in_pages_readable(buf, len); |
| bytes -= len; |
| iov++; |
| iov_ofs = 0; |
| } while (bytes); |
| } |
| |
| /** |
| * __ntfs_grab_cache_pages - obtain a number of locked pages |
| * @mapping: address space mapping from which to obtain page cache pages |
| * @index: starting index in @mapping at which to begin obtaining pages |
| * @nr_pages: number of page cache pages to obtain |
| * @pages: array of pages in which to return the obtained page cache pages |
| * @cached_page: allocated but as yet unused page |
| * @lru_pvec: lru-buffering pagevec of caller |
| * |
| * Obtain @nr_pages locked page cache pages from the mapping @maping and |
| * starting at index @index. |
| * |
| * If a page is newly created, increment its refcount and add it to the |
| * caller's lru-buffering pagevec @lru_pvec. |
| * |
| * This is the same as mm/filemap.c::__grab_cache_page(), except that @nr_pages |
| * are obtained at once instead of just one page and that 0 is returned on |
| * success and -errno on error. |
| * |
| * Note, the page locks are obtained in ascending page index order. |
| */ |
| static inline int __ntfs_grab_cache_pages(struct address_space *mapping, |
| pgoff_t index, const unsigned nr_pages, struct page **pages, |
| struct page **cached_page, struct pagevec *lru_pvec) |
| { |
| int err, nr; |
| |
| BUG_ON(!nr_pages); |
| err = nr = 0; |
| do { |
| pages[nr] = find_lock_page(mapping, index); |
| if (!pages[nr]) { |
| if (!*cached_page) { |
| *cached_page = page_cache_alloc(mapping); |
| if (unlikely(!*cached_page)) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| } |
| err = add_to_page_cache(*cached_page, mapping, index, |
| GFP_KERNEL); |
| if (unlikely(err)) { |
| if (err == -EEXIST) |
| continue; |
| goto err_out; |
| } |
| pages[nr] = *cached_page; |
| page_cache_get(*cached_page); |
| if (unlikely(!pagevec_add(lru_pvec, *cached_page))) |
| __pagevec_lru_add(lru_pvec); |
| *cached_page = NULL; |
| } |
| index++; |
| nr++; |
| } while (nr < nr_pages); |
| out: |
| return err; |
| err_out: |
| while (nr > 0) { |
| unlock_page(pages[--nr]); |
| page_cache_release(pages[nr]); |
| } |
| goto out; |
| } |
| |
| static inline int ntfs_submit_bh_for_read(struct buffer_head *bh) |
| { |
| lock_buffer(bh); |
| get_bh(bh); |
| bh->b_end_io = end_buffer_read_sync; |
| return submit_bh(READ, bh); |
| } |
| |
| /** |
| * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data |
| * @pages: array of destination pages |
| * @nr_pages: number of pages in @pages |
| * @pos: byte position in file at which the write begins |
| * @bytes: number of bytes to be written |
| * |
| * This is called for non-resident attributes from ntfs_file_buffered_write() |
| * with i_mutex held on the inode (@pages[0]->mapping->host). There are |
| * @nr_pages pages in @pages which are locked but not kmap()ped. The source |
| * data has not yet been copied into the @pages. |
| * |
| * Need to fill any holes with actual clusters, allocate buffers if necessary, |
| * ensure all the buffers are mapped, and bring uptodate any buffers that are |
| * only partially being written to. |
| * |
| * If @nr_pages is greater than one, we are guaranteed that the cluster size is |
| * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside |
| * the same cluster and that they are the entirety of that cluster, and that |
| * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole. |
| * |
| * i_size is not to be modified yet. |
| * |
| * Return 0 on success or -errno on error. |
| */ |
| static int ntfs_prepare_pages_for_non_resident_write(struct page **pages, |
| unsigned nr_pages, s64 pos, size_t bytes) |
| { |
| VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend; |
| LCN lcn; |
| s64 bh_pos, vcn_len, end, initialized_size; |
| sector_t lcn_block; |
| struct page *page; |
| struct inode *vi; |
| ntfs_inode *ni, *base_ni = NULL; |
| ntfs_volume *vol; |
| runlist_element *rl, *rl2; |
| struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; |
| ntfs_attr_search_ctx *ctx = NULL; |
| MFT_RECORD *m = NULL; |
| ATTR_RECORD *a = NULL; |
| unsigned long flags; |
| u32 attr_rec_len = 0; |
| unsigned blocksize, u; |
| int err, mp_size; |
| bool rl_write_locked, was_hole, is_retry; |
| unsigned char blocksize_bits; |
| struct { |
| u8 runlist_merged:1; |
| u8 mft_attr_mapped:1; |
| u8 mp_rebuilt:1; |
| u8 attr_switched:1; |
| } status = { 0, 0, 0, 0 }; |
| |
| BUG_ON(!nr_pages); |
| BUG_ON(!pages); |
| BUG_ON(!*pages); |
| vi = pages[0]->mapping->host; |
| ni = NTFS_I(vi); |
| vol = ni->vol; |
| ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page " |
| "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.", |
| vi->i_ino, ni->type, pages[0]->index, nr_pages, |
| (long long)pos, bytes); |
| blocksize = vol->sb->s_blocksize; |
| blocksize_bits = vol->sb->s_blocksize_bits; |
| u = 0; |
| do { |
| struct page *page = pages[u]; |
| /* |
| * 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); |
| if (unlikely(!page_has_buffers(page))) |
| return -ENOMEM; |
| } |
| } while (++u < nr_pages); |
| rl_write_locked = false; |
| rl = NULL; |
| err = 0; |
| vcn = lcn = -1; |
| vcn_len = 0; |
| lcn_block = -1; |
| was_hole = false; |
| cpos = pos >> vol->cluster_size_bits; |
| end = pos + bytes; |
| cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits; |
| /* |
| * Loop over each page and for each page over each buffer. Use goto to |
| * reduce indentation. |
| */ |
| u = 0; |
| do_next_page: |
| page = pages[u]; |
| bh_pos = (s64)page->index << PAGE_CACHE_SHIFT; |
| bh = head = page_buffers(page); |
| do { |
| VCN cdelta; |
| s64 bh_end; |
| unsigned bh_cofs; |
| |
| /* Clear buffer_new on all buffers to reinitialise state. */ |
| if (buffer_new(bh)) |
| clear_buffer_new(bh); |
| bh_end = bh_pos + blocksize; |
| bh_cpos = bh_pos >> vol->cluster_size_bits; |
| bh_cofs = bh_pos & vol->cluster_size_mask; |
| if (buffer_mapped(bh)) { |
| /* |
| * The buffer is already mapped. If it is uptodate, |
| * ignore it. |
| */ |
| if (buffer_uptodate(bh)) |
| continue; |
| /* |
| * The buffer is not uptodate. If the page is uptodate |
| * set the buffer uptodate and otherwise ignore it. |
| */ |
| if (PageUptodate(page)) { |
| set_buffer_uptodate(bh); |
| continue; |
| } |
| /* |
| * Neither the page nor the buffer are uptodate. If |
| * the buffer is only partially being written to, we |
| * need to read it in before the write, i.e. now. |
| */ |
| if ((bh_pos < pos && bh_end > pos) || |
| (bh_pos < end && bh_end > end)) { |
| /* |
| * If the buffer is fully or partially within |
| * the initialized size, do an actual read. |
| * Otherwise, simply zero the buffer. |
| */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| initialized_size = ni->initialized_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| if (bh_pos < initialized_size) { |
| ntfs_submit_bh_for_read(bh); |
| *wait_bh++ = bh; |
| } else { |
| u8 *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); |
| } |
| } |
| continue; |
| } |
| /* Unmapped buffer. Need to map it. */ |
| bh->b_bdev = vol->sb->s_bdev; |
| /* |
| * If the current buffer is in the same clusters as the map |
| * cache, there is no need to check the runlist again. The |
| * map cache is made up of @vcn, which is the first cached file |
| * cluster, @vcn_len which is the number of cached file |
| * clusters, @lcn is the device cluster corresponding to @vcn, |
| * and @lcn_block is the block number corresponding to @lcn. |
| */ |
| cdelta = bh_cpos - vcn; |
| if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) { |
| map_buffer_cached: |
| BUG_ON(lcn < 0); |
| bh->b_blocknr = lcn_block + |
| (cdelta << (vol->cluster_size_bits - |
| blocksize_bits)) + |
| (bh_cofs >> blocksize_bits); |
| set_buffer_mapped(bh); |
| /* |
| * If the page is uptodate so is the buffer. If the |
| * buffer is fully outside the write, we ignore it if |
| * it was already allocated and we mark it dirty so it |
| * gets written out if we allocated it. On the other |
| * hand, if we allocated the buffer but we are not |
| * marking it dirty we set buffer_new so we can do |
| * error recovery. |
| */ |
| if (PageUptodate(page)) { |
| if (!buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| if (unlikely(was_hole)) { |
| /* We allocated the buffer. */ |
| unmap_underlying_metadata(bh->b_bdev, |
| bh->b_blocknr); |
| if (bh_end <= pos || bh_pos >= end) |
| mark_buffer_dirty(bh); |
| else |
| set_buffer_new(bh); |
| } |
| continue; |
| } |
| /* Page is _not_ uptodate. */ |
| if (likely(!was_hole)) { |
| /* |
| * Buffer was already allocated. If it is not |
| * uptodate and is only partially being written |
| * to, we need to read it in before the write, |
| * i.e. now. |
| */ |
| if (!buffer_uptodate(bh) && bh_pos < end && |
| bh_end > pos && |
| (bh_pos < pos || |
| bh_end > end)) { |
| /* |
| * If the buffer is fully or partially |
| * within the initialized size, do an |
| * actual read. Otherwise, simply zero |
| * the buffer. |
| */ |
| read_lock_irqsave(&ni->size_lock, |
| flags); |
| initialized_size = ni->initialized_size; |
| read_unlock_irqrestore(&ni->size_lock, |
| flags); |
| if (bh_pos < initialized_size) { |
| ntfs_submit_bh_for_read(bh); |
| *wait_bh++ = bh; |
| } else { |
| u8 *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); |
| } |
| } |
| continue; |
| } |
| /* We allocated the buffer. */ |
| unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); |
| /* |
| * If the buffer is fully outside the write, zero it, |
| * set it uptodate, and mark it dirty so it gets |
| * written out. If it is partially being written to, |
| * zero region surrounding the write but leave it to |
| * commit write to do anything else. Finally, if the |
| * buffer is fully being overwritten, do nothing. |
| */ |
| if (bh_end <= pos || bh_pos >= end) { |
| if (!buffer_uptodate(bh)) { |
| u8 *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); |
| } |
| mark_buffer_dirty(bh); |
| continue; |
| } |
| set_buffer_new(bh); |
| if (!buffer_uptodate(bh) && |
| (bh_pos < pos || bh_end > end)) { |
| u8 *kaddr; |
| unsigned pofs; |
| |
| kaddr = kmap_atomic(page, KM_USER0); |
| if (bh_pos < pos) { |
| pofs = bh_pos & ~PAGE_CACHE_MASK; |
| memset(kaddr + pofs, 0, pos - bh_pos); |
| } |
| if (bh_end > end) { |
| pofs = end & ~PAGE_CACHE_MASK; |
| memset(kaddr + pofs, 0, bh_end - end); |
| } |
| kunmap_atomic(kaddr, KM_USER0); |
| flush_dcache_page(page); |
| } |
| continue; |
| } |
| /* |
| * Slow path: this is the first buffer in the cluster. If it |
| * is outside allocated size and is not uptodate, zero it and |
| * set it uptodate. |
| */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| initialized_size = ni->allocated_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| if (bh_pos > initialized_size) { |
| if (PageUptodate(page)) { |
| if (!buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| } else if (!buffer_uptodate(bh)) { |
| u8 *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); |
| } |
| continue; |
| } |
| is_retry = false; |
| if (!rl) { |
| down_read(&ni->runlist.lock); |
| retry_remap: |
| rl = ni->runlist.rl; |
| } |
| if (likely(rl != NULL)) { |
| /* Seek to element containing target cluster. */ |
| while (rl->length && rl[1].vcn <= bh_cpos) |
| rl++; |
| lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos); |
| if (likely(lcn >= 0)) { |
| /* |
| * Successful remap, setup the map cache and |
| * use that to deal with the buffer. |
| */ |
| was_hole = false; |
| vcn = bh_cpos; |
| vcn_len = rl[1].vcn - vcn; |
| lcn_block = lcn << (vol->cluster_size_bits - |
| blocksize_bits); |
| cdelta = 0; |
| /* |
| * If the number of remaining clusters touched |
| * by the write is smaller or equal to the |
| * number of cached clusters, unlock the |
| * runlist as the map cache will be used from |
| * now on. |
| */ |
| if (likely(vcn + vcn_len >= cend)) { |
| if (rl_write_locked) { |
| up_write(&ni->runlist.lock); |
| rl_write_locked = false; |
| } else |
| up_read(&ni->runlist.lock); |
| rl = NULL; |
| } |
| goto map_buffer_cached; |
| } |
| } else |
| lcn = LCN_RL_NOT_MAPPED; |
| /* |
| * If it is not a hole and not out of bounds, the runlist is |
| * probably unmapped so try to map it now. |
| */ |
| if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) { |
| if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) { |
| /* Attempt to map runlist. */ |
| if (!rl_write_locked) { |
| /* |
| * We need the runlist locked for |
| * writing, so if it is locked for |
| * reading relock it now and retry in |
| * case it changed whilst we dropped |
| * the lock. |
| */ |
| up_read(&ni->runlist.lock); |
| down_write(&ni->runlist.lock); |
| rl_write_locked = true; |
| goto retry_remap; |
| } |
| err = ntfs_map_runlist_nolock(ni, bh_cpos, |
| NULL); |
| if (likely(!err)) { |
| is_retry = true; |
| goto retry_remap; |
| } |
| /* |
| * If @vcn is out of bounds, pretend @lcn is |
| * LCN_ENOENT. As long as the buffer is out |
| * of bounds this will work fine. |
| */ |
| if (err == -ENOENT) { |
| lcn = LCN_ENOENT; |
| err = 0; |
| goto rl_not_mapped_enoent; |
| } |
| } else |
| err = -EIO; |
| /* Failed to map the buffer, even after retrying. */ |
| bh->b_blocknr = -1; |
| ntfs_error(vol->sb, "Failed to write to inode 0x%lx, " |
| "attribute type 0x%x, vcn 0x%llx, " |
| "vcn offset 0x%x, because its " |
| "location on disk could not be " |
| "determined%s (error code %i).", |
| ni->mft_no, ni->type, |
| (unsigned long long)bh_cpos, |
| (unsigned)bh_pos & |
| vol->cluster_size_mask, |
| is_retry ? " even after retrying" : "", |
| err); |
| break; |
| } |
| rl_not_mapped_enoent: |
| /* |
| * The buffer is in a hole or out of bounds. We need to fill |
| * the hole, unless the buffer is in a cluster which is not |
| * touched by the write, in which case we just leave the buffer |
| * unmapped. This can only happen when the cluster size is |
| * less than the page cache size. |
| */ |
| if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) { |
| bh_cend = (bh_end + vol->cluster_size - 1) >> |
| vol->cluster_size_bits; |
| if ((bh_cend <= cpos || bh_cpos >= cend)) { |
| bh->b_blocknr = -1; |
| /* |
| * If the buffer is uptodate we skip it. If it |
| * is not but the page is uptodate, we can set |
| * the buffer uptodate. If the page is not |
| * uptodate, we can clear the buffer and set it |
| * uptodate. Whether this is worthwhile is |
| * debatable and this could be removed. |
| */ |
| if (PageUptodate(page)) { |
| if (!buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| } else if (!buffer_uptodate(bh)) { |
| u8 *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); |
| } |
| continue; |
| } |
| } |
| /* |
| * Out of bounds buffer is invalid if it was not really out of |
| * bounds. |
| */ |
| BUG_ON(lcn != LCN_HOLE); |
| /* |
| * We need the runlist locked for writing, so if it is locked |
| * for reading relock it now and retry in case it changed |
| * whilst we dropped the lock. |
| */ |
| BUG_ON(!rl); |
| if (!rl_write_locked) { |
| up_read(&ni->runlist.lock); |
| down_write(&ni->runlist.lock); |
| rl_write_locked = true; |
| goto retry_remap; |
| } |
| /* Find the previous last allocated cluster. */ |
| BUG_ON(rl->lcn != LCN_HOLE); |
| lcn = -1; |
| rl2 = rl; |
| while (--rl2 >= ni->runlist.rl) { |
| if (rl2->lcn >= 0) { |
| lcn = rl2->lcn + rl2->length; |
| break; |
| } |
| } |
| rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE, |
| false); |
| if (IS_ERR(rl2)) { |
| err = PTR_ERR(rl2); |
| ntfs_debug("Failed to allocate cluster, error code %i.", |
| err); |
| break; |
| } |
| lcn = rl2->lcn; |
| rl = ntfs_runlists_merge(ni->runlist.rl, rl2); |
| if (IS_ERR(rl)) { |
| err = PTR_ERR(rl); |
| if (err != -ENOMEM) |
| err = -EIO; |
| if (ntfs_cluster_free_from_rl(vol, rl2)) { |
| ntfs_error(vol->sb, "Failed to release " |
| "allocated cluster in error " |
| "code path. Run chkdsk to " |
| "recover the lost cluster."); |
| NVolSetErrors(vol); |
| } |
| ntfs_free(rl2); |
| break; |
| } |
| ni->runlist.rl = rl; |
| status.runlist_merged = 1; |
| ntfs_debug("Allocated cluster, lcn 0x%llx.", |
| (unsigned long long)lcn); |
| /* Map and lock the mft record and get the attribute record. */ |
| if (!NInoAttr(ni)) |
| base_ni = ni; |
| else |
| base_ni = ni->ext.base_ntfs_ino; |
| m = map_mft_record(base_ni); |
| if (IS_ERR(m)) { |
| err = PTR_ERR(m); |
| break; |
| } |
| ctx = ntfs_attr_get_search_ctx(base_ni, m); |
| if (unlikely(!ctx)) { |
| err = -ENOMEM; |
| unmap_mft_record(base_ni); |
| break; |
| } |
| status.mft_attr_mapped = 1; |
| err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, bh_cpos, NULL, 0, ctx); |
| if (unlikely(err)) { |
| if (err == -ENOENT) |
| err = -EIO; |
| break; |
| } |
| m = ctx->mrec; |
| a = ctx->attr; |
| /* |
| * Find the runlist element with which the attribute extent |
| * starts. Note, we cannot use the _attr_ version because we |
| * have mapped the mft record. That is ok because we know the |
| * runlist fragment must be mapped already to have ever gotten |
| * here, so we can just use the _rl_ version. |
| */ |
| vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn); |
| rl2 = ntfs_rl_find_vcn_nolock(rl, vcn); |
| BUG_ON(!rl2); |
| BUG_ON(!rl2->length); |
| BUG_ON(rl2->lcn < LCN_HOLE); |
| highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn); |
| /* |
| * If @highest_vcn is zero, calculate the real highest_vcn |
| * (which can really be zero). |
| */ |
| if (!highest_vcn) |
| highest_vcn = (sle64_to_cpu( |
| a->data.non_resident.allocated_size) >> |
| vol->cluster_size_bits) - 1; |
| /* |
| * Determine the size of the mapping pairs array for the new |
| * extent, i.e. the old extent with the hole filled. |
| */ |
| mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn, |
| highest_vcn); |
| if (unlikely(mp_size <= 0)) { |
| if (!(err = mp_size)) |
| err = -EIO; |
| ntfs_debug("Failed to get size for mapping pairs " |
| "array, error code %i.", err); |
| break; |
| } |
| /* |
| * Resize the attribute record to fit the new mapping pairs |
| * array. |
| */ |
| attr_rec_len = le32_to_cpu(a->length); |
| err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu( |
| a->data.non_resident.mapping_pairs_offset)); |
| if (unlikely(err)) { |
| BUG_ON(err != -ENOSPC); |
| // TODO: Deal with this by using the current attribute |
| // and fill it with as much of the mapping pairs |
| // array as possible. Then loop over each attribute |
| // extent rewriting the mapping pairs arrays as we go |
| // along and if when we reach the end we have not |
| // enough space, try to resize the last attribute |
| // extent and if even that fails, add a new attribute |
| // extent. |
| // We could also try to resize at each step in the hope |
| // that we will not need to rewrite every single extent. |
| // Note, we may need to decompress some extents to fill |
| // the runlist as we are walking the extents... |
| ntfs_error(vol->sb, "Not enough space in the mft " |
| "record for the extended attribute " |
| "record. This case is not " |
| "implemented yet."); |
| err = -EOPNOTSUPP; |
| break ; |
| } |
| status.mp_rebuilt = 1; |
| /* |
| * Generate the mapping pairs array directly into the attribute |
| * record. |
| */ |
| err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( |
| a->data.non_resident.mapping_pairs_offset), |
| mp_size, rl2, vcn, highest_vcn, NULL); |
| if (unlikely(err)) { |
| ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, " |
| "attribute type 0x%x, because building " |
| "the mapping pairs failed with error " |
| "code %i.", vi->i_ino, |
| (unsigned)le32_to_cpu(ni->type), err); |
| err = -EIO; |
| break; |
| } |
| /* Update the highest_vcn but only if it was not set. */ |
| if (unlikely(!a->data.non_resident.highest_vcn)) |
| a->data.non_resident.highest_vcn = |
| cpu_to_sle64(highest_vcn); |
| /* |
| * If the attribute is sparse/compressed, update the compressed |
| * size in the ntfs_inode structure and the attribute record. |
| */ |
| if (likely(NInoSparse(ni) || NInoCompressed(ni))) { |
| /* |
| * If we are not in the first attribute extent, switch |
| * to it, but first ensure the changes will make it to |
| * disk later. |
| */ |
| if (a->data.non_resident.lowest_vcn) { |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| ntfs_attr_reinit_search_ctx(ctx); |
| err = ntfs_attr_lookup(ni->type, ni->name, |
| ni->name_len, CASE_SENSITIVE, |
| 0, NULL, 0, ctx); |
| if (unlikely(err)) { |
| status.attr_switched = 1; |
| break; |
| } |
| /* @m is not used any more so do not set it. */ |
| a = ctx->attr; |
| } |
| write_lock_irqsave(&ni->size_lock, flags); |
| ni->itype.compressed.size += vol->cluster_size; |
| a->data.non_resident.compressed_size = |
| cpu_to_sle64(ni->itype.compressed.size); |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| } |
| /* Ensure the changes make it to disk. */ |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| ntfs_attr_put_search_ctx(ctx); |
| unmap_mft_record(base_ni); |
| /* Successfully filled the hole. */ |
| status.runlist_merged = 0; |
| status.mft_attr_mapped = 0; |
| status.mp_rebuilt = 0; |
| /* Setup the map cache and use that to deal with the buffer. */ |
| was_hole = true; |
| vcn = bh_cpos; |
| vcn_len = 1; |
| lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits); |
| cdelta = 0; |
| /* |
| * If the number of remaining clusters in the @pages is smaller |
| * or equal to the number of cached clusters, unlock the |
| * runlist as the map cache will be used from now on. |
| */ |
| if (likely(vcn + vcn_len >= cend)) { |
| up_write(&ni->runlist.lock); |
| rl_write_locked = false; |
| rl = NULL; |
| } |
| goto map_buffer_cached; |
| } while (bh_pos += blocksize, (bh = bh->b_this_page) != head); |
| /* If there are no errors, do the next page. */ |
| if (likely(!err && ++u < nr_pages)) |
| goto do_next_page; |
| /* If there are no errors, release the runlist lock if we took it. */ |
| if (likely(!err)) { |
| if (unlikely(rl_write_locked)) { |
| up_write(&ni->runlist.lock); |
| rl_write_locked = false; |
| } else if (unlikely(rl)) |
| up_read(&ni->runlist.lock); |
| rl = NULL; |
| } |
| /* If we issued read requests, let them complete. */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| initialized_size = ni->initialized_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| while (wait_bh > wait) { |
| bh = *--wait_bh; |
| wait_on_buffer(bh); |
| if (likely(buffer_uptodate(bh))) { |
| page = bh->b_page; |
| bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) + |
| bh_offset(bh); |
| /* |
| * If the buffer overflows the initialized size, need |
| * to zero the overflowing region. |
| */ |
| if (unlikely(bh_pos + blocksize > initialized_size)) { |
| u8 *kaddr; |
| int ofs = 0; |
| |
| if (likely(bh_pos < initialized_size)) |
| ofs = initialized_size - bh_pos; |
| kaddr = kmap_atomic(page, KM_USER0); |
| memset(kaddr + bh_offset(bh) + ofs, 0, |
| blocksize - ofs); |
| kunmap_atomic(kaddr, KM_USER0); |
| flush_dcache_page(page); |
| } |
| } else /* if (unlikely(!buffer_uptodate(bh))) */ |
| err = -EIO; |
| } |
| if (likely(!err)) { |
| /* Clear buffer_new on all buffers. */ |
| u = 0; |
| do { |
| bh = head = page_buffers(pages[u]); |
| do { |
| if (buffer_new(bh)) |
| clear_buffer_new(bh); |
| } while ((bh = bh->b_this_page) != head); |
| } while (++u < nr_pages); |
| ntfs_debug("Done."); |
| return err; |
| } |
| if (status.attr_switched) { |
| /* Get back to the attribute extent we modified. */ |
| ntfs_attr_reinit_search_ctx(ctx); |
| if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) { |
| ntfs_error(vol->sb, "Failed to find required " |
| "attribute extent of attribute in " |
| "error code path. Run chkdsk to " |
| "recover."); |
| write_lock_irqsave(&ni->size_lock, flags); |
| ni->itype.compressed.size += vol->cluster_size; |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| /* |
| * The only thing that is now wrong is the compressed |
| * size of the base attribute extent which chkdsk |
| * should be able to fix. |
| */ |
| NVolSetErrors(vol); |
| } else { |
| m = ctx->mrec; |
| a = ctx->attr; |
| status.attr_switched = 0; |
| } |
| } |
| /* |
| * If the runlist has been modified, need to restore it by punching a |
| * hole into it and we then need to deallocate the on-disk cluster as |
| * well. Note, we only modify the runlist if we are able to generate a |
| * new mapping pairs array, i.e. only when the mapped attribute extent |
| * is not switched. |
| */ |
| if (status.runlist_merged && !status.attr_switched) { |
| BUG_ON(!rl_write_locked); |
| /* Make the file cluster we allocated sparse in the runlist. */ |
| if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) { |
| ntfs_error(vol->sb, "Failed to punch hole into " |
| "attribute runlist in error code " |
| "path. Run chkdsk to recover the " |
| "lost cluster."); |
| NVolSetErrors(vol); |
| } else /* if (success) */ { |
| status.runlist_merged = 0; |
| /* |
| * Deallocate the on-disk cluster we allocated but only |
| * if we succeeded in punching its vcn out of the |
| * runlist. |
| */ |
| down_write(&vol->lcnbmp_lock); |
| if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { |
| ntfs_error(vol->sb, "Failed to release " |
| "allocated cluster in error " |
| "code path. Run chkdsk to " |
| "recover the lost cluster."); |
| NVolSetErrors(vol); |
| } |
| up_write(&vol->lcnbmp_lock); |
| } |
| } |
| /* |
| * Resize the attribute record to its old size and rebuild the mapping |
| * pairs array. Note, we only can do this if the runlist has been |
| * restored to its old state which also implies that the mapped |
| * attribute extent is not switched. |
| */ |
| if (status.mp_rebuilt && !status.runlist_merged) { |
| if (ntfs_attr_record_resize(m, a, attr_rec_len)) { |
| ntfs_error(vol->sb, "Failed to restore attribute " |
| "record in error code path. Run " |
| "chkdsk to recover."); |
| NVolSetErrors(vol); |
| } else /* if (success) */ { |
| if (ntfs_mapping_pairs_build(vol, (u8*)a + |
| le16_to_cpu(a->data.non_resident. |
| mapping_pairs_offset), attr_rec_len - |
| le16_to_cpu(a->data.non_resident. |
| mapping_pairs_offset), ni->runlist.rl, |
| vcn, highest_vcn, NULL)) { |
| ntfs_error(vol->sb, "Failed to restore " |
| "mapping pairs array in error " |
| "code path. Run chkdsk to " |
| "recover."); |
| NVolSetErrors(vol); |
| } |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| } |
| } |
| /* Release the mft record and the attribute. */ |
| if (status.mft_attr_mapped) { |
| ntfs_attr_put_search_ctx(ctx); |
| unmap_mft_record(base_ni); |
| } |
| /* Release the runlist lock. */ |
| if (rl_write_locked) |
| up_write(&ni->runlist.lock); |
| else if (rl) |
| up_read(&ni->runlist.lock); |
| /* |
| * Zero out any newly allocated blocks to avoid exposing stale data. |
| * If BH_New is set, we know that the block was newly allocated above |
| * and that it has not been fully zeroed and marked dirty yet. |
| */ |
| nr_pages = u; |
| u = 0; |
| end = bh_cpos << vol->cluster_size_bits; |
| do { |
| page = pages[u]; |
| bh = head = page_buffers(page); |
| do { |
| if (u == nr_pages && |
| ((s64)page->index << PAGE_CACHE_SHIFT) + |
| bh_offset(bh) >= end) |
| break; |
| if (!buffer_new(bh)) |
| continue; |
| clear_buffer_new(bh); |
| if (!buffer_uptodate(bh)) { |
| if (PageUptodate(page)) |
| set_buffer_uptodate(bh); |
| else { |
| u8 *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); |
| } |
| } |
| mark_buffer_dirty(bh); |
| } while ((bh = bh->b_this_page) != head); |
| } while (++u <= nr_pages); |
| ntfs_error(vol->sb, "Failed. Returning error code %i.", err); |
| return err; |
| } |
| |
| /* |
| * Copy as much as we can into the pages and return the number of bytes which |
| * were sucessfully copied. If a fault is encountered then clear the pages |
| * out to (ofs + bytes) and return the number of bytes which were copied. |
| */ |
| static inline size_t ntfs_copy_from_user(struct page **pages, |
| unsigned nr_pages, unsigned ofs, const char __user *buf, |
| size_t bytes) |
| { |
| struct page **last_page = pages + nr_pages; |
| char *kaddr; |
| size_t total = 0; |
| unsigned len; |
| int left; |
| |
| do { |
| len = PAGE_CACHE_SIZE - ofs; |
| if (len > bytes) |
| len = bytes; |
| kaddr = kmap_atomic(*pages, KM_USER0); |
| left = __copy_from_user_inatomic(kaddr + ofs, buf, len); |
| kunmap_atomic(kaddr, KM_USER0); |
| if (unlikely(left)) { |
| /* Do it the slow way. */ |
| kaddr = kmap(*pages); |
| left = __copy_from_user(kaddr + ofs, buf, len); |
| kunmap(*pages); |
| if (unlikely(left)) |
| goto err_out; |
| } |
| total += len; |
| bytes -= len; |
| if (!bytes) |
| break; |
| buf += len; |
| ofs = 0; |
| } while (++pages < last_page); |
| out: |
| return total; |
| err_out: |
| total += len - left; |
| /* Zero the rest of the target like __copy_from_user(). */ |
| while (++pages < last_page) { |
| bytes -= len; |
| if (!bytes) |
| break; |
| len = PAGE_CACHE_SIZE; |
| if (len > bytes) |
| len = bytes; |
| kaddr = kmap_atomic(*pages, KM_USER0); |
| memset(kaddr, 0, len); |
| kunmap_atomic(kaddr, KM_USER0); |
| } |
| goto out; |
| } |
| |
| static size_t __ntfs_copy_from_user_iovec_inatomic(char *vaddr, |
| const struct iovec *iov, size_t iov_ofs, size_t bytes) |
| { |
| size_t total = 0; |
| |
| while (1) { |
| const char __user *buf = iov->iov_base + iov_ofs; |
| unsigned len; |
| size_t left; |
| |
| len = iov->iov_len - iov_ofs; |
| if (len > bytes) |
| len = bytes; |
| left = __copy_from_user_inatomic(vaddr, buf, len); |
| total += len; |
| bytes -= len; |
| vaddr += len; |
| if (unlikely(left)) { |
| total -= left; |
| break; |
| } |
| if (!bytes) |
| break; |
| iov++; |
| iov_ofs = 0; |
| } |
| return total; |
| } |
| |
| static inline void ntfs_set_next_iovec(const struct iovec **iovp, |
| size_t *iov_ofsp, size_t bytes) |
| { |
| const struct iovec *iov = *iovp; |
| size_t iov_ofs = *iov_ofsp; |
| |
| while (bytes) { |
| unsigned len; |
| |
| len = iov->iov_len - iov_ofs; |
| if (len > bytes) |
| len = bytes; |
| bytes -= len; |
| iov_ofs += len; |
| if (iov->iov_len == iov_ofs) { |
| iov++; |
| iov_ofs = 0; |
| } |
| } |
| *iovp = iov; |
| *iov_ofsp = iov_ofs; |
| } |
| |
| /* |
| * This has the same side-effects and return value as ntfs_copy_from_user(). |
| * The difference is that on a fault we need to memset the remainder of the |
| * pages (out to offset + bytes), to emulate ntfs_copy_from_user()'s |
| * single-segment behaviour. |
| * |
| * We call the same helper (__ntfs_copy_from_user_iovec_inatomic()) both |
| * when atomic and when not atomic. This is ok because |
| * __ntfs_copy_from_user_iovec_inatomic() calls __copy_from_user_inatomic() |
| * and it is ok to call this when non-atomic. |
| * Infact, the only difference between __copy_from_user_inatomic() and |
| * __copy_from_user() is that the latter calls might_sleep() and the former |
| * should not zero the tail of the buffer on error. And on many |
| * architectures __copy_from_user_inatomic() is just defined to |
| * __copy_from_user() so it makes no difference at all on those architectures. |
| */ |
| static inline size_t ntfs_copy_from_user_iovec(struct page **pages, |
| unsigned nr_pages, unsigned ofs, const struct iovec **iov, |
| size_t *iov_ofs, size_t bytes) |
| { |
| struct page **last_page = pages + nr_pages; |
| char *kaddr; |
| size_t copied, len, total = 0; |
| |
| do { |
| len = PAGE_CACHE_SIZE - ofs; |
| if (len > bytes) |
| len = bytes; |
| kaddr = kmap_atomic(*pages, KM_USER0); |
| copied = __ntfs_copy_from_user_iovec_inatomic(kaddr + ofs, |
| *iov, *iov_ofs, len); |
| kunmap_atomic(kaddr, KM_USER0); |
| if (unlikely(copied != len)) { |
| /* Do it the slow way. */ |
| kaddr = kmap(*pages); |
| copied = __ntfs_copy_from_user_iovec_inatomic(kaddr + ofs, |
| *iov, *iov_ofs, len); |
| /* |
| * Zero the rest of the target like __copy_from_user(). |
| */ |
| memset(kaddr + ofs + copied, 0, len - copied); |
| kunmap(*pages); |
| if (unlikely(copied != len)) |
| goto err_out; |
| } |
| total += len; |
| bytes -= len; |
| if (!bytes) |
| break; |
| ntfs_set_next_iovec(iov, iov_ofs, len); |
| ofs = 0; |
| } while (++pages < last_page); |
| out: |
| return total; |
| err_out: |
| total += copied; |
| /* Zero the rest of the target like __copy_from_user(). */ |
| while (++pages < last_page) { |
| bytes -= len; |
| if (!bytes) |
| break; |
| len = PAGE_CACHE_SIZE; |
| if (len > bytes) |
| len = bytes; |
| kaddr = kmap_atomic(*pages, KM_USER0); |
| memset(kaddr, 0, len); |
| kunmap_atomic(kaddr, KM_USER0); |
| } |
| goto out; |
| } |
| |
| static inline void ntfs_flush_dcache_pages(struct page **pages, |
| unsigned nr_pages) |
| { |
| BUG_ON(!nr_pages); |
| /* |
| * Warning: Do not do the decrement at the same time as the call to |
| * flush_dcache_page() because it is a NULL macro on i386 and hence the |
| * decrement never happens so the loop never terminates. |
| */ |
| do { |
| --nr_pages; |
| flush_dcache_page(pages[nr_pages]); |
| } while (nr_pages > 0); |
| } |
| |
| /** |
| * ntfs_commit_pages_after_non_resident_write - commit the received data |
| * @pages: array of destination pages |
| * @nr_pages: number of pages in @pages |
| * @pos: byte position in file at which the write begins |
| * @bytes: number of bytes to be written |
| * |
| * See description of ntfs_commit_pages_after_write(), below. |
| */ |
| static inline int ntfs_commit_pages_after_non_resident_write( |
| struct page **pages, const unsigned nr_pages, |
| s64 pos, size_t bytes) |
| { |
| s64 end, initialized_size; |
| struct inode *vi; |
| ntfs_inode *ni, *base_ni; |
| struct buffer_head *bh, *head; |
| ntfs_attr_search_ctx *ctx; |
| MFT_RECORD *m; |
| ATTR_RECORD *a; |
| unsigned long flags; |
| unsigned blocksize, u; |
| int err; |
| |
| vi = pages[0]->mapping->host; |
| ni = NTFS_I(vi); |
| blocksize = vi->i_sb->s_blocksize; |
| end = pos + bytes; |
| u = 0; |
| do { |
| s64 bh_pos; |
| struct page *page; |
| bool partial; |
| |
| page = pages[u]; |
| bh_pos = (s64)page->index << PAGE_CACHE_SHIFT; |
| bh = head = page_buffers(page); |
| partial = false; |
| do { |
| s64 bh_end; |
| |
| bh_end = bh_pos + blocksize; |
| if (bh_end <= pos || bh_pos >= end) { |
| if (!buffer_uptodate(bh)) |
| partial = true; |
| } else { |
| set_buffer_uptodate(bh); |
| mark_buffer_dirty(bh); |
| } |
| } while (bh_pos += blocksize, (bh = bh->b_this_page) != head); |
| /* |
| * If all buffers are now uptodate but the page is not, set the |
| * page uptodate. |
| */ |
| if (!partial && !PageUptodate(page)) |
| SetPageUptodate(page); |
| } while (++u < nr_pages); |
| /* |
| * Finally, if we do not need to update initialized_size or i_size we |
| * are finished. |
| */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| initialized_size = ni->initialized_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| if (end <= initialized_size) { |
| ntfs_debug("Done."); |
| return 0; |
| } |
| /* |
| * Update initialized_size/i_size as appropriate, both in the inode and |
| * the mft record. |
| */ |
| 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 (IS_ERR(m)) { |
| err = PTR_ERR(m); |
| m = NULL; |
| ctx = NULL; |
| goto err_out; |
| } |
| BUG_ON(!NInoNonResident(ni)); |
| ctx = ntfs_attr_get_search_ctx(base_ni, m); |
| if (unlikely(!ctx)) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, 0, NULL, 0, ctx); |
| if (unlikely(err)) { |
| if (err == -ENOENT) |
| err = -EIO; |
| goto err_out; |
| } |
| a = ctx->attr; |
| BUG_ON(!a->non_resident); |
| write_lock_irqsave(&ni->size_lock, flags); |
| BUG_ON(end > ni->allocated_size); |
| ni->initialized_size = end; |
| a->data.non_resident.initialized_size = cpu_to_sle64(end); |
| if (end > i_size_read(vi)) { |
| i_size_write(vi, end); |
| a->data.non_resident.data_size = |
| a->data.non_resident.initialized_size; |
| } |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| /* Mark the mft record dirty, so it gets written back. */ |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| ntfs_attr_put_search_ctx(ctx); |
| unmap_mft_record(base_ni); |
| ntfs_debug("Done."); |
| return 0; |
| err_out: |
| if (ctx) |
| ntfs_attr_put_search_ctx(ctx); |
| if (m) |
| unmap_mft_record(base_ni); |
| ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error " |
| "code %i).", err); |
| if (err != -ENOMEM) |
| NVolSetErrors(ni->vol); |
| return err; |
| } |
| |
| /** |
| * ntfs_commit_pages_after_write - commit the received data |
| * @pages: array of destination pages |
| * @nr_pages: number of pages in @pages |
| * @pos: byte position in file at which the write begins |
| * @bytes: number of bytes to be written |
| * |
| * This is called from ntfs_file_buffered_write() with i_mutex held on the inode |
| * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are |
| * locked but not kmap()ped. The source data has already been copied into the |
| * @page. ntfs_prepare_pages_for_non_resident_write() has been called before |
| * the data was copied (for non-resident attributes only) and it returned |
| * success. |
| * |
| * Need to set uptodate and mark dirty all buffers within the boundary of the |
| * write. If all buffers in a page are uptodate we set the page uptodate, too. |
| * |
| * Setting the buffers dirty ensures that they get written out later when |
| * ntfs_writepage() is invoked by the VM. |
| * |
| * Finally, we need to update i_size and initialized_size as appropriate both |
| * in the inode and the mft record. |
| * |
| * This is modelled after fs/buffer.c::generic_commit_write(), which 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. |
| * |
| * If things have gone as outlined in |
| * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page |
| * content modifications here for non-resident attributes. For resident |
| * attributes we need to do the uptodate bringing here which we combine with |
| * the copying into the mft record which means we save one atomic kmap. |
| * |
| * Return 0 on success or -errno on error. |
| */ |
| static int ntfs_commit_pages_after_write(struct page **pages, |
| const unsigned nr_pages, s64 pos, size_t bytes) |
| { |
| s64 end, initialized_size; |
| loff_t i_size; |
| struct inode *vi; |
| ntfs_inode *ni, *base_ni; |
| struct page *page; |
| ntfs_attr_search_ctx *ctx; |
| MFT_RECORD *m; |
| ATTR_RECORD *a; |
| char *kattr, *kaddr; |
| unsigned long flags; |
| u32 attr_len; |
| int err; |
| |
| BUG_ON(!nr_pages); |
| BUG_ON(!pages); |
| page = pages[0]; |
| BUG_ON(!page); |
| vi = page->mapping->host; |
| ni = NTFS_I(vi); |
| ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page " |
| "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.", |
| vi->i_ino, ni->type, page->index, nr_pages, |
| (long long)pos, bytes); |
| if (NInoNonResident(ni)) |
| return ntfs_commit_pages_after_non_resident_write(pages, |
| nr_pages, pos, bytes); |
| BUG_ON(nr_pages > 1); |
| /* |
| * Attribute is resident, implying it is not compressed, encrypted, or |
| * sparse. |
| */ |
| if (!NInoAttr(ni)) |
| base_ni = ni; |
| else |
| base_ni = ni->ext.base_ntfs_ino; |
| BUG_ON(NInoNonResident(ni)); |
| /* Map, pin, and lock the mft record. */ |
| m = map_mft_record(base_ni); |
| if (IS_ERR(m)) { |
| err = PTR_ERR(m); |
| m = NULL; |
| ctx = NULL; |
| goto err_out; |
| } |
| ctx = ntfs_attr_get_search_ctx(base_ni, m); |
| if (unlikely(!ctx)) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, |
| CASE_SENSITIVE, 0, NULL, 0, ctx); |
| if (unlikely(err)) { |
| if (err == -ENOENT) |
| err = -EIO; |
| goto err_out; |
| } |
| a = ctx->attr; |
| BUG_ON(a->non_resident); |
| /* The total length of the attribute value. */ |
| attr_len = le32_to_cpu(a->data.resident.value_length); |
| i_size = i_size_read(vi); |
| BUG_ON(attr_len != i_size); |
| BUG_ON(pos > attr_len); |
| end = pos + bytes; |
| BUG_ON(end > le32_to_cpu(a->length) - |
| le16_to_cpu(a->data.resident.value_offset)); |
| kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset); |
| kaddr = kmap_atomic(page, KM_USER0); |
| /* Copy the received data from the page to the mft record. */ |
| memcpy(kattr + pos, kaddr + pos, bytes); |
| /* Update the attribute length if necessary. */ |
| if (end > attr_len) { |
| attr_len = end; |
| a->data.resident.value_length = cpu_to_le32(attr_len); |
| } |
| /* |
| * If the page is not uptodate, bring the out of bounds area(s) |
| * uptodate by copying data from the mft record to the page. |
| */ |
| if (!PageUptodate(page)) { |
| if (pos > 0) |
| memcpy(kaddr, kattr, pos); |
| if (end < attr_len) |
| memcpy(kaddr + end, kattr + end, attr_len - end); |
| /* Zero the region outside the end of the attribute value. */ |
| memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len); |
| flush_dcache_page(page); |
| SetPageUptodate(page); |
| } |
| kunmap_atomic(kaddr, KM_USER0); |
| /* Update initialized_size/i_size if necessary. */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| initialized_size = ni->initialized_size; |
| BUG_ON(end > ni->allocated_size); |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| BUG_ON(initialized_size != i_size); |
| if (end > initialized_size) { |
| unsigned long flags; |
| |
| write_lock_irqsave(&ni->size_lock, flags); |
| ni->initialized_size = end; |
| i_size_write(vi, end); |
| write_unlock_irqrestore(&ni->size_lock, flags); |
| } |
| /* Mark the mft record dirty, so it gets written back. */ |
| flush_dcache_mft_record_page(ctx->ntfs_ino); |
| mark_mft_record_dirty(ctx->ntfs_ino); |
| ntfs_attr_put_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 |
| * buffers' 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 commit write failed " |
| "with error %i.", err); |
| NVolSetErrors(ni->vol); |
| } |
| if (ctx) |
| ntfs_attr_put_search_ctx(ctx); |
| if (m) |
| unmap_mft_record(base_ni); |
| return err; |
| } |
| |
| /** |
| * ntfs_file_buffered_write - |
| * |
| * Locking: The vfs is holding ->i_mutex on the inode. |
| */ |
| static ssize_t ntfs_file_buffered_write(struct kiocb *iocb, |
| const struct iovec *iov, unsigned long nr_segs, |
| loff_t pos, loff_t *ppos, size_t count) |
| { |
| struct file *file = iocb->ki_filp; |
| struct address_space *mapping = file->f_mapping; |
| struct inode *vi = mapping->host; |
| ntfs_inode *ni = NTFS_I(vi); |
| ntfs_volume *vol = ni->vol; |
| struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER]; |
| struct page *cached_page = NULL; |
| char __user *buf = NULL; |
| s64 end, ll; |
| VCN last_vcn; |
| LCN lcn; |
| unsigned long flags; |
| size_t bytes, iov_ofs = 0; /* Offset in the current iovec. */ |
| ssize_t status, written; |
| unsigned nr_pages; |
| int err; |
| struct pagevec lru_pvec; |
| |
| ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, " |
| "pos 0x%llx, count 0x%lx.", |
| vi->i_ino, (unsigned)le32_to_cpu(ni->type), |
| (unsigned long long)pos, (unsigned long)count); |
| if (unlikely(!count)) |
| return 0; |
| BUG_ON(NInoMstProtected(ni)); |
| /* |
| * If the attribute is not an index root and it is encrypted or |
| * compressed, we cannot write to it yet. 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)) { |
| /* |
| * Reminder for later: Encrypted files are _always_ |
| * non-resident so that the content can always be |
| * encrypted. |
| */ |
| ntfs_debug("Denying write access to encrypted file."); |
| return -EACCES; |
| } |
| if (NInoCompressed(ni)) { |
| /* Only unnamed $DATA attribute can be compressed. */ |
| BUG_ON(ni->type != AT_DATA); |
| BUG_ON(ni->name_len); |
| /* |
| * Reminder for later: If resident, the data is not |
| * actually compressed. Only on the switch to non- |
| * resident does compression kick in. This is in |
| * contrast to encrypted files (see above). |
| */ |
| ntfs_error(vi->i_sb, "Writing to compressed files is " |
| "not implemented yet. Sorry."); |
| return -EOPNOTSUPP; |
| } |
| } |
| /* |
| * If a previous ntfs_truncate() failed, repeat it and abort if it |
| * fails again. |
| */ |
| if (unlikely(NInoTruncateFailed(ni))) { |
| down_write(&vi->i_alloc_sem); |
| err = ntfs_truncate(vi); |
| up_write(&vi->i_alloc_sem); |
| if (err || NInoTruncateFailed(ni)) { |
| if (!err) |
| err = -EIO; |
| ntfs_error(vol->sb, "Cannot perform write to inode " |
| "0x%lx, attribute type 0x%x, because " |
| "ntfs_truncate() failed (error code " |
| "%i).", vi->i_ino, |
| (unsigned)le32_to_cpu(ni->type), err); |
| return err; |
| } |
| } |
| /* The first byte after the write. */ |
| end = pos + count; |
| /* |
| * If the write goes beyond the allocated size, extend the allocation |
| * to cover the whole of the write, rounded up to the nearest cluster. |
| */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| ll = ni->allocated_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| if (end > ll) { |
| /* Extend the allocation without changing the data size. */ |
| ll = ntfs_attr_extend_allocation(ni, end, -1, pos); |
| if (likely(ll >= 0)) { |
| BUG_ON(pos >= ll); |
| /* If the extension was partial truncate the write. */ |
| if (end > ll) { |
| ntfs_debug("Truncating write to inode 0x%lx, " |
| "attribute type 0x%x, because " |
| "the allocation was only " |
| "partially extended.", |
| vi->i_ino, (unsigned) |
| le32_to_cpu(ni->type)); |
| end = ll; |
| count = ll - pos; |
| } |
| } else { |
| err = ll; |
| read_lock_irqsave(&ni->size_lock, flags); |
| ll = ni->allocated_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| /* Perform a partial write if possible or fail. */ |
| if (pos < ll) { |
| ntfs_debug("Truncating write to inode 0x%lx, " |
| "attribute type 0x%x, because " |
| "extending the allocation " |
| "failed (error code %i).", |
| vi->i_ino, (unsigned) |
| le32_to_cpu(ni->type), err); |
| end = ll; |
| count = ll - pos; |
| } else { |
| ntfs_error(vol->sb, "Cannot perform write to " |
| "inode 0x%lx, attribute type " |
| "0x%x, because extending the " |
| "allocation failed (error " |
| "code %i).", vi->i_ino, |
| (unsigned) |
| le32_to_cpu(ni->type), err); |
| return err; |
| } |
| } |
| } |
| pagevec_init(&lru_pvec, 0); |
| written = 0; |
| /* |
| * If the write starts beyond the initialized size, extend it up to the |
| * beginning of the write and initialize all non-sparse space between |
| * the old initialized size and the new one. This automatically also |
| * increments the vfs inode->i_size to keep it above or equal to the |
| * initialized_size. |
| */ |
| read_lock_irqsave(&ni->size_lock, flags); |
| ll = ni->initialized_size; |
| read_unlock_irqrestore(&ni->size_lock, flags); |
| if (pos > ll) { |
| err = ntfs_attr_extend_initialized(ni, pos, &cached_page, |
| &lru_pvec); |
| if (err < 0) { |
| ntfs_error(vol->sb, "Cannot perform write to inode " |
| "0x%lx, attribute type 0x%x, because " |
| "extending the initialized size " |
| "failed (error code %i).", vi->i_ino, |
| (unsigned)le32_to_cpu(ni->type), err); |
| status = err; |
| goto err_out; |
| } |
| } |
| /* |
| * Determine the number of pages per cluster for non-resident |
| * attributes. |
| */ |
| nr_pages = 1; |
| if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni)) |
| nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT; |
| /* Finally, perform the actual write. */ |
| last_vcn = -1; |
| if (likely(nr_segs == 1)) |
| buf = iov->iov_base; |
| do { |
| VCN vcn; |
| pgoff_t idx, start_idx; |
| unsigned ofs, do_pages, u; |
| size_t copied; |
| |
| start_idx = idx = pos >> PAGE_CACHE_SHIFT; |
| ofs = pos & ~PAGE_CACHE_MASK; |
| bytes = PAGE_CACHE_SIZE - ofs; |
| do_pages = 1; |
| if (nr_pages > 1) { |
| vcn = pos >> vol->cluster_size_bits; |
| if (vcn != last_vcn) { |
| last_vcn = vcn; |
| /* |
| * Get the lcn of the vcn the write is in. If |
| * it is a hole, need to lock down all pages in |
| * the cluster. |
| */ |
| down_read(&ni->runlist.lock); |
| lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >> |
| vol->cluster_size_bits, false); |
| up_read(&ni->runlist.lock); |
| if (unlikely(lcn < LCN_HOLE)) { |
| status = -EIO; |
| if (lcn == LCN_ENOMEM) |
| status = -ENOMEM; |
| else |
| ntfs_error(vol->sb, "Cannot " |
| "perform write to " |
| "inode 0x%lx, " |
| "attribute type 0x%x, " |
| "because the attribute " |
| "is corrupt.", |
| vi->i_ino, (unsigned) |
| le32_to_cpu(ni->type)); |
| break; |
| } |
| if (lcn == LCN_HOLE) { |
| start_idx = (pos & ~(s64) |
| vol->cluster_size_mask) |
| >> PAGE_CACHE_SHIFT; |
| bytes = vol->cluster_size - (pos & |
| vol->cluster_size_mask); |
| do_pages = nr_pages; |
| } |
| } |
| } |
| if (bytes > count) |
| bytes = count; |
| /* |
| * Bring in the user page(s) that we will copy from _first_. |
| * Otherwise there is a nasty deadlock on copying from the same |
| * page(s) as we are writing to, without it/them being marked |
| * up-to-date. Note, at present there is nothing to stop the |
| * pages being swapped out between us bringing them into memory |
| * and doing the actual copying. |
| */ |
| if (likely(nr_segs == 1)) |
| ntfs_fault_in_pages_readable(buf, bytes); |
| else |
| ntfs_fault_in_pages_readable_iovec(iov, iov_ofs, bytes); |
| /* Get and lock @do_pages starting at index @start_idx. */ |
| status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages, |
| pages, &cached_page, &lru_pvec); |
| if (unlikely(status)) |
| break; |
| /* |
| * For non-resident attributes, we need to fill any holes with |
| * actual clusters and ensure all bufferes are mapped. We also |
| * need to bring uptodate any buffers that are only partially |
| * being written to. |
| */ |
| if (NInoNonResident(ni)) { |
| status = ntfs_prepare_pages_for_non_resident_write( |
| pages, do_pages, pos, bytes); |
| if (unlikely(status)) { |
| loff_t i_size; |
| |
| do { |
| unlock_page(pages[--do_pages]); |
| page_cache_release(pages[do_pages]); |
| } while (do_pages); |
| /* |
| * The write preparation may have instantiated |
| * allocated space outside i_size. Trim this |
| * off again. We can ignore any errors in this |
| * case as we will just be waisting a bit of |
| * allocated space, which is not a disaster. |
| */ |
| i_size = i_size_read(vi); |
| if (pos + bytes > i_size) |
| vmtruncate(vi, i_size); |
| break; |
| } |
| } |
| u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index; |
| if (likely(nr_segs == 1)) { |
| copied = ntfs_copy_from_user(pages + u, do_pages - u, |
| ofs, buf, bytes); |
| buf += copied; |
| } else |
| copied = ntfs_copy_from_user_iovec(pages + u, |
| do_pages - u, ofs, &iov, &iov_ofs, |
| bytes); |
| ntfs_flush_dcache_pages(pages + u, do_pages - u); |
| status = ntfs_commit_pages_after_write(pages, do_pages, pos, |
| bytes); |
| if (likely(!status)) { |
| written += copied; |
| count -= copied; |
| pos += copied; |
| if (unlikely(copied != bytes)) |
| status = -EFAULT; |
| } |
| do { |
| unlock_page(pages[--do_pages]); |
| mark_page_accessed(pages[do_pages]); |
| page_cache_release(pages[do_pages]); |
| } while (do_pages); |
| if (unlikely(status)) |
| break; |
| balance_dirty_pages_ratelimited(mapping); |
| cond_resched(); |
| } while (count); |
| err_out: |
| *ppos = pos; |
| if (cached_page) |
| page_cache_release(cached_page); |
| /* For now, when the user asks for O_SYNC, we actually give O_DSYNC. */ |
| if (likely(!status)) { |
| if (unlikely((file->f_flags & O_SYNC) || IS_SYNC(vi))) { |
| if (!mapping->a_ops->writepage || !is_sync_kiocb(iocb)) |
| status = generic_osync_inode(vi, mapping, |
| OSYNC_METADATA|OSYNC_DATA); |
| } |
| } |
| pagevec_lru_add(&lru_pvec); |
| ntfs_debug("Done. Returning %s (written 0x%lx, status %li).", |
| written ? "written" : "status", (unsigned long)written, |
| (long)status); |
| return written ? written : status; |
| } |
| |
| /** |
| * ntfs_file_aio_write_nolock - |
| */ |
| static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb, |
| const struct iovec *iov, unsigned long nr_segs, loff_t *ppos) |
| { |
| struct file *file = iocb->ki_filp; |
| struct address_space *mapping = file->f_mapping; |
| struct inode *inode = mapping->host; |
| loff_t pos; |
| unsigned long seg; |
| size_t count; /* after file limit checks */ |
| ssize_t written, err; |
| |
| count = 0; |
| for (seg = 0; seg < nr_segs; seg++) { |
| const struct iovec *iv = &iov[seg]; |
| /* |
| * If any segment has a negative length, or the cumulative |
| * length ever wraps negative then return -EINVAL. |
| */ |
| count += iv->iov_len; |
| if (unlikely((ssize_t)(count|iv->iov_len) < 0)) |
| return -EINVAL; |
| if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len)) |
| continue; |
| if (!seg) |
| return -EFAULT; |
| nr_segs = seg; |
| count -= iv->iov_len; /* This segment is no good */ |
| break; |
| } |
| pos = *ppos; |
| vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); |
| /* We can write back this queue in page reclaim. */ |
| current->backing_dev_info = mapping->backing_dev_info; |
| written = 0; |
| err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
| if (err) |
| goto out; |
| if (!count) |
| goto out; |
| err = remove_suid(file->f_dentry); |
| if (err) |
| goto out; |
| file_update_time(file); |
| written = ntfs_file_buffered_write(iocb, iov, nr_segs, pos, ppos, |
| count); |
| out: |
| current->backing_dev_info = NULL; |
| return written ? written : err; |
| } |
| |
| /** |
| * ntfs_file_aio_write - |
| */ |
| static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const char __user *buf, |
| size_t count, loff_t pos) |
| { |
| struct file *file = iocb->ki_filp; |
| struct address_space *mapping = file->f_mapping; |
| struct inode *inode = mapping->host; |
| ssize_t ret; |
| struct iovec local_iov = { .iov_base = (void __user *)buf, |
| .iov_len = count }; |
| |
| BUG_ON(iocb->ki_pos != pos); |
| |
| mutex_lock(&inode->i_mutex); |
| ret = ntfs_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos); |
| mutex_unlock(&inode->i_mutex); |
| if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) { |
| int err = sync_page_range(inode, mapping, pos, ret); |
| if (err < 0) |
| ret = err; |
| } |
| return ret; |
| } |
| |
| /** |
| * ntfs_file_writev - |
| * |
| * Basically the same as generic_file_writev() except that it ends up calling |
| * ntfs_file_aio_write_nolock() instead of __generic_file_aio_write_nolock(). |
| */ |
| static ssize_t ntfs_file_writev(struct file *file, const struct iovec *iov, |
| unsigned long nr_segs, loff_t *ppos) |
| { |
| struct address_space *mapping = file->f_mapping; |
| struct inode *inode = mapping->host; |
| struct kiocb kiocb; |
| ssize_t ret; |
| |
| mutex_lock(&inode->i_mutex); |
| init_sync_kiocb(&kiocb, file); |
| ret = ntfs_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos); |
| if (ret == -EIOCBQUEUED) |
| ret = wait_on_sync_kiocb(&kiocb); |
| mutex_unlock(&inode->i_mutex); |
| if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) { |
| int err = sync_page_range(inode, mapping, *ppos - ret, ret); |
| if (err < 0) |
| ret = err; |
| } |
| return ret; |
| } |
| |
| /** |
| * ntfs_file_write - simple wrapper for ntfs_file_writev() |
| */ |
| static ssize_t ntfs_file_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct iovec local_iov = { .iov_base = (void __user *)buf, |
| .iov_len = count }; |
| |
| return ntfs_file_writev(file, &local_iov, 1, ppos); |
| } |
| |
| /** |
| * ntfs_file_fsync - sync a file to disk |
| * @filp: file to be synced |
| * @dentry: dentry describing the file to sync |
| * @datasync: if non-zero only flush user data and not metadata |
| * |
| * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync |
| * system calls. This function is inspired by fs/buffer.c::file_fsync(). |
| * |
| * If @datasync is false, write the mft record and all associated extent mft |
| * records as well as the $DATA attribute and then sync the block device. |
| * |
| * If @datasync is true and the attribute is non-resident, we skip the writing |
| * of the mft record and all associated extent mft records (this might still |
| * happen due to the write_inode_now() call). |
| * |
| * Also, if @datasync is true, we do not wait on the inode to be written out |
| * but we always wait on the page cache pages to be written out. |
| * |
| * Note: In the past @filp could be NULL so we ignore it as we don't need it |
| * anyway. |
| * |
| * Locking: Caller must hold i_mutex on the inode. |
| * |
| * TODO: We should probably also write all attribute/index inodes associated |
| * with this inode but since we have no simple way of getting to them we ignore |
| * this problem for now. |
| */ |
| static int ntfs_file_fsync(struct file *filp, struct dentry *dentry, |
| int datasync) |
| { |
| struct inode *vi = dentry->d_inode; |
| int err, ret = 0; |
| |
| ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); |
| BUG_ON(S_ISDIR(vi->i_mode)); |
| if (!datasync || !NInoNonResident(NTFS_I(vi))) |
| ret = ntfs_write_inode(vi, 1); |
| write_inode_now(vi, !datasync); |
| /* |
| * NOTE: If we were to use mapping->private_list (see ext2 and |
| * fs/buffer.c) for dirty blocks then we could optimize the below to be |
| * sync_mapping_buffers(vi->i_mapping). |
| */ |
| err = sync_blockdev(vi->i_sb->s_bdev); |
| if (unlikely(err && !ret)) |
| ret = err; |
| if (likely(!ret)) |
| ntfs_debug("Done."); |
| else |
| ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " |
| "%u.", datasync ? "data" : "", vi->i_ino, -ret); |
| return ret; |
| } |
| |
| #endif /* NTFS_RW */ |
| |
| const struct file_operations ntfs_file_ops = { |
| .llseek = generic_file_llseek, /* Seek inside file. */ |
| .read = generic_file_read, /* Read from file. */ |
| .aio_read = generic_file_aio_read, /* Async read from file. */ |
| .readv = generic_file_readv, /* Read from file. */ |
| #ifdef NTFS_RW |
| .write = ntfs_file_write, /* Write to file. */ |
| .aio_write = ntfs_file_aio_write, /* Async write to file. */ |
| .writev = ntfs_file_writev, /* Write to file. */ |
| /*.release = ,*/ /* Last file is closed. See |
| fs/ext2/file.c:: |
| ext2_release_file() for |
| how to use this to discard |
| preallocated space for |
| write opened files. */ |
| .fsync = ntfs_file_fsync, /* Sync a file to disk. */ |
| /*.aio_fsync = ,*/ /* Sync all outstanding async |
| i/o operations on a |
| kiocb. */ |
| #endif /* NTFS_RW */ |
| /*.ioctl = ,*/ /* Perform function on the |
| mounted filesystem. */ |
| .mmap = generic_file_mmap, /* Mmap file. */ |
| .open = ntfs_file_open, /* Open file. */ |
| .sendfile = generic_file_sendfile, /* Zero-copy data send with |
| the data source being on |
| the ntfs partition. We do |
| not need to care about the |
| data destination. */ |
| /*.sendpage = ,*/ /* Zero-copy data send with |
| the data destination being |
| on the ntfs partition. We |
| do not need to care about |
| the data source. */ |
| }; |
| |
| struct inode_operations ntfs_file_inode_ops = { |
| #ifdef NTFS_RW |
| .truncate = ntfs_truncate_vfs, |
| .setattr = ntfs_setattr, |
| #endif /* NTFS_RW */ |
| }; |
| |
| const struct file_operations ntfs_empty_file_ops = {}; |
| |
| struct inode_operations ntfs_empty_inode_ops = {}; |