From 07a4e2da7dd3c9345f84b2552872f9d38c257451 Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov <aia21@cantab.net> Date: Wed, 12 Jan 2005 13:08:26 +0000 Subject: NTFS: Use i_size_{read,write}() in fs/ntfs/{aops.c,mft.c} and protect access to the i_size and other size fields using the size_lock. Signed-off-by: Anton Altaparmakov <aia21@cantab.net> --- fs/ntfs/aops.c | 56 +++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 15 deletions(-) (limited to 'fs/ntfs/aops.c') diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index 45d56e41ed98..a53212793809 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -66,19 +66,22 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate) ni = NTFS_I(page->mapping->host); if (likely(uptodate)) { - s64 file_ofs; + s64 file_ofs, initialized_size; set_buffer_uptodate(bh); file_ofs = ((s64)page->index << PAGE_CACHE_SHIFT) + bh_offset(bh); + read_lock_irqsave(&ni->size_lock, flags); + initialized_size = ni->initialized_size; + read_unlock_irqrestore(&ni->size_lock, flags); /* Check for the current buffer head overflowing. */ - if (file_ofs + bh->b_size > ni->initialized_size) { + if (file_ofs + bh->b_size > initialized_size) { char *addr; int ofs = 0; - if (file_ofs < ni->initialized_size) - ofs = ni->initialized_size - file_ofs; + if (file_ofs < initialized_size) + ofs = initialized_size - file_ofs; addr = kmap_atomic(page, KM_BIO_SRC_IRQ); memset(addr + bh_offset(bh) + ofs, 0, bh->b_size - ofs); flush_dcache_page(page); @@ -168,6 +171,7 @@ static int ntfs_read_block(struct page *page) 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; @@ -190,8 +194,10 @@ static int ntfs_read_block(struct page *page) } 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; + read_unlock_irqrestore(&ni->size_lock, flags); /* Loop through all the buffers in the page. */ rl = NULL; @@ -463,12 +469,15 @@ 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; runlist_element *rl; struct buffer_head *bh, *head; + unsigned long flags; unsigned int blocksize, vcn_ofs; int err; BOOL need_end_writeback; @@ -510,11 +519,16 @@ static int ntfs_write_block(struct page *page, struct writeback_control *wbc) /* The first block in the page. */ 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 @@ -559,7 +573,7 @@ static int ntfs_write_block(struct page *page, struct writeback_control *wbc) /* 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 @@ -846,7 +860,7 @@ static int ntfs_write_mst_block(struct page *page, (PAGE_CACHE_SHIFT - bh_size_bits); /* The first out of bounds block for the data size. */ - dblock = (vi->i_size + bh_size - 1) >> bh_size_bits; + dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits; rl = NULL; err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0; @@ -1367,7 +1381,7 @@ static int ntfs_writepage(struct page *page, struct writeback_control *wbc) */ attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); - i_size = i_size_read(VFS_I(ni)); + i_size = i_size_read(vi); kaddr = kmap_atomic(page, KM_USER0); if (unlikely(attr_len > i_size)) { /* Zero out of bounds area in the mft record. */ @@ -1425,12 +1439,15 @@ static int ntfs_prepare_nonresident_write(struct page *page, { VCN vcn; LCN lcn; + s64 initialized_size; + loff_t i_size; sector_t block, ablock, iblock; struct inode *vi; ntfs_inode *ni; ntfs_volume *vol; runlist_element *rl; struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; + unsigned long flags; unsigned int vcn_ofs, block_start, block_end, blocksize; int err; BOOL is_retry; @@ -1462,6 +1479,7 @@ static int ntfs_prepare_nonresident_write(struct page *page, /* The first block in the page. */ block = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits); + read_lock_irqsave(&ni->size_lock, flags); /* * 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 @@ -1470,8 +1488,12 @@ static int ntfs_prepare_nonresident_write(struct page *page, */ ablock = ni->allocated_size >> blocksize_bits; + i_size = i_size_read(vi); + initialized_size = ni->initialized_size; + read_unlock_irqrestore(&ni->size_lock, flags); + /* The last (fully or partially) initialized block. */ - iblock = ni->initialized_size >> blocksize_bits; + iblock = initialized_size >> blocksize_bits; /* Loop through all the buffers in the page. */ block_start = 0; @@ -1518,7 +1540,7 @@ static int ntfs_prepare_nonresident_write(struct page *page, * request, i.e. block < ablock is true. */ 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 @@ -1868,7 +1890,7 @@ static int ntfs_prepare_write(struct file *file, struct page *page, BUG_ON(page_has_buffers(page)); new_size = ((s64)page->index << PAGE_CACHE_SHIFT) + to; /* If we do not need to resize the attribute allocation we are done. */ - if (new_size <= vi->i_size) + if (new_size <= i_size_read(vi)) goto done; // FIXME: We abort for now as this code is not safe. @@ -1904,7 +1926,7 @@ static int ntfs_prepare_write(struct file *file, struct page *page, a = ctx->attr; /* The total length of the attribute value. */ attr_len = le32_to_cpu(a->data.resident.value_length); - BUG_ON(vi->i_size != attr_len); + BUG_ON(i_size_read(vi) != attr_len); /* Check if new size is allowed in $AttrDef. */ err = ntfs_attr_size_bounds_check(vol, ni->type, new_size); if (unlikely(err)) { @@ -2047,7 +2069,7 @@ static int ntfs_commit_nonresident_write(struct page *page, * 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) { + if (pos > i_size_read(vi)) { ntfs_error(vi->i_sb, "Writing beyond the existing file size is " "not supported yet. Sorry."); return -EOPNOTSUPP; @@ -2183,9 +2205,13 @@ static int ntfs_commit_write(struct file *file, struct page *page, } kunmap_atomic(kaddr, KM_USER0); /* Update i_size if necessary. */ - if (vi->i_size < attr_len) { + if (i_size_read(vi) < attr_len) { + unsigned long flags; + + write_lock_irqsave(&ni->size_lock, flags); ni->allocated_size = ni->initialized_size = attr_len; i_size_write(vi, attr_len); + 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); -- cgit v1.2.3-58-ga151