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Diffstat (limited to 'fs/ntfs/mft.c')
| -rw-r--r-- | fs/ntfs/mft.c | 2829 |
1 files changed, 2829 insertions, 0 deletions
diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c new file mode 100644 index 000000000000..dfa85ac2f8ba --- /dev/null +++ b/fs/ntfs/mft.c @@ -0,0 +1,2829 @@ +/** + * mft.c - NTFS kernel mft record operations. Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2004 Anton Altaparmakov + * Copyright (c) 2002 Richard Russon + * + * 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/swap.h> + +#include "attrib.h" +#include "aops.h" +#include "bitmap.h" +#include "debug.h" +#include "dir.h" +#include "lcnalloc.h" +#include "malloc.h" +#include "mft.h" +#include "ntfs.h" + +/** + * map_mft_record_page - map the page in which a specific mft record resides + * @ni: ntfs inode whose mft record page to map + * + * This maps the page in which the mft record of the ntfs inode @ni is situated + * and returns a pointer to the mft record within the mapped page. + * + * Return value needs to be checked with IS_ERR() and if that is true PTR_ERR() + * contains the negative error code returned. + */ +static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni) +{ + ntfs_volume *vol = ni->vol; + struct inode *mft_vi = vol->mft_ino; + struct page *page; + unsigned long index, ofs, end_index; + + BUG_ON(ni->page); + /* + * The index into the page cache and the offset within the page cache + * page of the wanted mft record. FIXME: We need to check for + * overflowing the unsigned long, but I don't think we would ever get + * here if the volume was that big... + */ + index = ni->mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; + ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; + + /* The maximum valid index into the page cache for $MFT's data. */ + end_index = mft_vi->i_size >> PAGE_CACHE_SHIFT; + + /* If the wanted index is out of bounds the mft record doesn't exist. */ + if (unlikely(index >= end_index)) { + if (index > end_index || (mft_vi->i_size & ~PAGE_CACHE_MASK) < + ofs + vol->mft_record_size) { + page = ERR_PTR(-ENOENT); + ntfs_error(vol->sb, "Attemt to read mft record 0x%lx, " + "which is beyond the end of the mft. " + "This is probably a bug in the ntfs " + "driver.", ni->mft_no); + goto err_out; + } + } + /* Read, map, and pin the page. */ + page = ntfs_map_page(mft_vi->i_mapping, index); + if (likely(!IS_ERR(page))) { + /* Catch multi sector transfer fixup errors. */ + if (likely(ntfs_is_mft_recordp((le32*)(page_address(page) + + ofs)))) { + ni->page = page; + ni->page_ofs = ofs; + return page_address(page) + ofs; + } + ntfs_error(vol->sb, "Mft record 0x%lx is corrupt. " + "Run chkdsk.", ni->mft_no); + ntfs_unmap_page(page); + page = ERR_PTR(-EIO); + } +err_out: + ni->page = NULL; + ni->page_ofs = 0; + return (void*)page; +} + +/** + * map_mft_record - map, pin and lock an mft record + * @ni: ntfs inode whose MFT record to map + * + * First, take the mrec_lock semaphore. We might now be sleeping, while waiting + * for the semaphore if it was already locked by someone else. + * + * The page of the record is mapped using map_mft_record_page() before being + * returned to the caller. + * + * This in turn uses ntfs_map_page() to get the page containing the wanted mft + * record (it in turn calls read_cache_page() which reads it in from disk if + * necessary, increments the use count on the page so that it cannot disappear + * under us and returns a reference to the page cache page). + * + * If read_cache_page() invokes ntfs_readpage() to load the page from disk, it + * sets PG_locked and clears PG_uptodate on the page. Once I/O has completed + * and the post-read mst fixups on each mft record in the page have been + * performed, the page gets PG_uptodate set and PG_locked cleared (this is done + * in our asynchronous I/O completion handler end_buffer_read_mft_async()). + * ntfs_map_page() waits for PG_locked to become clear and checks if + * PG_uptodate is set and returns an error code if not. This provides + * sufficient protection against races when reading/using the page. + * + * However there is the write mapping to think about. Doing the above described + * checking here will be fine, because when initiating the write we will set + * PG_locked and clear PG_uptodate making sure nobody is touching the page + * contents. Doing the locking this way means that the commit to disk code in + * the page cache code paths is automatically sufficiently locked with us as + * we will not touch a page that has been locked or is not uptodate. The only + * locking problem then is them locking the page while we are accessing it. + * + * So that code will end up having to own the mrec_lock of all mft + * records/inodes present in the page before I/O can proceed. In that case we + * wouldn't need to bother with PG_locked and PG_uptodate as nobody will be + * accessing anything without owning the mrec_lock semaphore. But we do need + * to use them because of the read_cache_page() invocation and the code becomes + * so much simpler this way that it is well worth it. + * + * The mft record is now ours and we return a pointer to it. You need to check + * the returned pointer with IS_ERR() and if that is true, PTR_ERR() will return + * the error code. + * + * NOTE: Caller is responsible for setting the mft record dirty before calling + * unmap_mft_record(). This is obviously only necessary if the caller really + * modified the mft record... + * Q: Do we want to recycle one of the VFS inode state bits instead? + * A: No, the inode ones mean we want to change the mft record, not we want to + * write it out. + */ +MFT_RECORD *map_mft_record(ntfs_inode *ni) +{ + MFT_RECORD *m; + + ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no); + + /* Make sure the ntfs inode doesn't go away. */ + atomic_inc(&ni->count); + + /* Serialize access to this mft record. */ + down(&ni->mrec_lock); + + m = map_mft_record_page(ni); + if (likely(!IS_ERR(m))) + return m; + + up(&ni->mrec_lock); + atomic_dec(&ni->count); + ntfs_error(ni->vol->sb, "Failed with error code %lu.", -PTR_ERR(m)); + return m; +} + +/** + * unmap_mft_record_page - unmap the page in which a specific mft record resides + * @ni: ntfs inode whose mft record page to unmap + * + * This unmaps the page in which the mft record of the ntfs inode @ni is + * situated and returns. This is a NOOP if highmem is not configured. + * + * The unmap happens via ntfs_unmap_page() which in turn decrements the use + * count on the page thus releasing it from the pinned state. + * + * We do not actually unmap the page from memory of course, as that will be + * done by the page cache code itself when memory pressure increases or + * whatever. + */ +static inline void unmap_mft_record_page(ntfs_inode *ni) +{ + BUG_ON(!ni->page); + + // TODO: If dirty, blah... + ntfs_unmap_page(ni->page); + ni->page = NULL; + ni->page_ofs = 0; + return; +} + +/** + * unmap_mft_record - release a mapped mft record + * @ni: ntfs inode whose MFT record to unmap + * + * We release the page mapping and the mrec_lock mutex which unmaps the mft + * record and releases it for others to get hold of. We also release the ntfs + * inode by decrementing the ntfs inode reference count. + * + * NOTE: If caller has modified the mft record, it is imperative to set the mft + * record dirty BEFORE calling unmap_mft_record(). + */ +void unmap_mft_record(ntfs_inode *ni) +{ + struct page *page = ni->page; + + BUG_ON(!page); + + ntfs_debug("Entering for mft_no 0x%lx.", ni->mft_no); + + unmap_mft_record_page(ni); + up(&ni->mrec_lock); + atomic_dec(&ni->count); + /* + * If pure ntfs_inode, i.e. no vfs inode attached, we leave it to + * ntfs_clear_extent_inode() in the extent inode case, and to the + * caller in the non-extent, yet pure ntfs inode case, to do the actual + * tear down of all structures and freeing of all allocated memory. + */ + return; +} + +/** + * map_extent_mft_record - load an extent inode and attach it to its base + * @base_ni: base ntfs inode + * @mref: mft reference of the extent inode to load + * @ntfs_ino: on successful return, pointer to the ntfs_inode structure + * + * Load the extent mft record @mref and attach it to its base inode @base_ni. + * Return the mapped extent mft record if IS_ERR(result) is false. Otherwise + * PTR_ERR(result) gives the negative error code. + * + * On successful return, @ntfs_ino contains a pointer to the ntfs_inode + * structure of the mapped extent inode. + */ +MFT_RECORD *map_extent_mft_record(ntfs_inode *base_ni, MFT_REF mref, + ntfs_inode **ntfs_ino) +{ + MFT_RECORD *m; + ntfs_inode *ni = NULL; + ntfs_inode **extent_nis = NULL; + int i; + unsigned long mft_no = MREF(mref); + u16 seq_no = MSEQNO(mref); + BOOL destroy_ni = FALSE; + + ntfs_debug("Mapping extent mft record 0x%lx (base mft record 0x%lx).", + mft_no, base_ni->mft_no); + /* Make sure the base ntfs inode doesn't go away. */ + atomic_inc(&base_ni->count); + /* + * Check if this extent inode has already been added to the base inode, + * in which case just return it. If not found, add it to the base + * inode before returning it. + */ + down(&base_ni->extent_lock); + if (base_ni->nr_extents > 0) { + extent_nis = base_ni->ext.extent_ntfs_inos; + for (i = 0; i < base_ni->nr_extents; i++) { + if (mft_no != extent_nis[i]->mft_no) + continue; + ni = extent_nis[i]; + /* Make sure the ntfs inode doesn't go away. */ + atomic_inc(&ni->count); + break; + } + } + if (likely(ni != NULL)) { + up(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + /* We found the record; just have to map and return it. */ + m = map_mft_record(ni); + /* map_mft_record() has incremented this on success. */ + atomic_dec(&ni->count); + if (likely(!IS_ERR(m))) { + /* Verify the sequence number. */ + if (likely(le16_to_cpu(m->sequence_number) == seq_no)) { + ntfs_debug("Done 1."); + *ntfs_ino = ni; + return m; + } + unmap_mft_record(ni); + ntfs_error(base_ni->vol->sb, "Found stale extent mft " + "reference! Corrupt file system. " + "Run chkdsk."); + return ERR_PTR(-EIO); + } +map_err_out: + ntfs_error(base_ni->vol->sb, "Failed to map extent " + "mft record, error code %ld.", -PTR_ERR(m)); + return m; + } + /* Record wasn't there. Get a new ntfs inode and initialize it. */ + ni = ntfs_new_extent_inode(base_ni->vol->sb, mft_no); + if (unlikely(!ni)) { + up(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + return ERR_PTR(-ENOMEM); + } + ni->vol = base_ni->vol; + ni->seq_no = seq_no; + ni->nr_extents = -1; + ni->ext.base_ntfs_ino = base_ni; + /* Now map the record. */ + m = map_mft_record(ni); + if (IS_ERR(m)) { + up(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + ntfs_clear_extent_inode(ni); + goto map_err_out; + } + /* Verify the sequence number if it is present. */ + if (seq_no && (le16_to_cpu(m->sequence_number) != seq_no)) { + ntfs_error(base_ni->vol->sb, "Found stale extent mft " + "reference! Corrupt file system. Run chkdsk."); + destroy_ni = TRUE; + m = ERR_PTR(-EIO); + goto unm_err_out; + } + /* Attach extent inode to base inode, reallocating memory if needed. */ + if (!(base_ni->nr_extents & 3)) { + ntfs_inode **tmp; + int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode *); + + tmp = (ntfs_inode **)kmalloc(new_size, GFP_NOFS); + if (unlikely(!tmp)) { + ntfs_error(base_ni->vol->sb, "Failed to allocate " + "internal buffer."); + destroy_ni = TRUE; + m = ERR_PTR(-ENOMEM); + goto unm_err_out; + } + if (base_ni->nr_extents) { + BUG_ON(!base_ni->ext.extent_ntfs_inos); + memcpy(tmp, base_ni->ext.extent_ntfs_inos, new_size - + 4 * sizeof(ntfs_inode *)); + kfree(base_ni->ext.extent_ntfs_inos); + } + base_ni->ext.extent_ntfs_inos = tmp; + } + base_ni->ext.extent_ntfs_inos[base_ni->nr_extents++] = ni; + up(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + ntfs_debug("Done 2."); + *ntfs_ino = ni; + return m; +unm_err_out: + unmap_mft_record(ni); + up(&base_ni->extent_lock); + atomic_dec(&base_ni->count); + /* + * If the extent inode was not attached to the base inode we need to + * release it or we will leak memory. + */ + if (destroy_ni) + ntfs_clear_extent_inode(ni); + return m; +} + +#ifdef NTFS_RW + +/** + * __mark_mft_record_dirty - set the mft record and the page containing it dirty + * @ni: ntfs inode describing the mapped mft record + * + * Internal function. Users should call mark_mft_record_dirty() instead. + * + * Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni, + * as well as the page containing the mft record, dirty. Also, mark the base + * vfs inode dirty. This ensures that any changes to the mft record are + * written out to disk. + * + * NOTE: We only set I_DIRTY_SYNC and I_DIRTY_DATASYNC (and not I_DIRTY_PAGES) + * on the base vfs inode, because even though file data may have been modified, + * it is dirty in the inode meta data rather than the data page cache of the + * inode, and thus there are no data pages that need writing out. Therefore, a + * full mark_inode_dirty() is overkill. A mark_inode_dirty_sync(), on the + * other hand, is not sufficient, because I_DIRTY_DATASYNC needs to be set to + * ensure ->write_inode is called from generic_osync_inode() and this needs to + * happen or the file data would not necessarily hit the device synchronously, + * even though the vfs inode has the O_SYNC flag set. Also, I_DIRTY_DATASYNC + * simply "feels" better than just I_DIRTY_SYNC, since the file data has not + * actually hit the block device yet, which is not what I_DIRTY_SYNC on its own + * would suggest. + */ +void __mark_mft_record_dirty(ntfs_inode *ni) +{ + ntfs_inode *base_ni; + + ntfs_debug("Entering for inode 0x%lx.", ni->mft_no); + BUG_ON(NInoAttr(ni)); + mark_ntfs_record_dirty(ni->page, ni->page_ofs); + /* Determine the base vfs inode and mark it dirty, too. */ + down(&ni->extent_lock); + if (likely(ni->nr_extents >= 0)) + base_ni = ni; + else + base_ni = ni->ext.base_ntfs_ino; + up(&ni->extent_lock); + __mark_inode_dirty(VFS_I(base_ni), I_DIRTY_SYNC | I_DIRTY_DATASYNC); +} + +static const char *ntfs_please_email = "Please email " + "linux-ntfs-dev@lists.sourceforge.net and say that you saw " + "this message. Thank you."; + +/** + * ntfs_sync_mft_mirror_umount - synchronise an mft record to the mft mirror + * @vol: ntfs volume on which the mft record to synchronize resides + * @mft_no: mft record number of mft record to synchronize + * @m: mapped, mst protected (extent) mft record to synchronize + * + * Write the mapped, mst protected (extent) mft record @m with mft record + * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol, + * bypassing the page cache and the $MFTMirr inode itself. + * + * This function is only for use at umount time when the mft mirror inode has + * already been disposed off. We BUG() if we are called while the mft mirror + * inode is still attached to the volume. + * + * On success return 0. On error return -errno. + * + * NOTE: This function is not implemented yet as I am not convinced it can + * actually be triggered considering the sequence of commits we do in super.c:: + * ntfs_put_super(). But just in case we provide this place holder as the + * alternative would be either to BUG() or to get a NULL pointer dereference + * and Oops. + */ +static int ntfs_sync_mft_mirror_umount(ntfs_volume *vol, + const unsigned long mft_no, MFT_RECORD *m) +{ + BUG_ON(vol->mftmirr_ino); + ntfs_error(vol->sb, "Umount time mft mirror syncing is not " + "implemented yet. %s", ntfs_please_email); + return -EOPNOTSUPP; +} + +/** + * ntfs_sync_mft_mirror - synchronize an mft record to the mft mirror + * @vol: ntfs volume on which the mft record to synchronize resides + * @mft_no: mft record number of mft record to synchronize + * @m: mapped, mst protected (extent) mft record to synchronize + * @sync: if true, wait for i/o completion + * + * Write the mapped, mst protected (extent) mft record @m with mft record + * number @mft_no to the mft mirror ($MFTMirr) of the ntfs volume @vol. + * + * On success return 0. On error return -errno and set the volume errors flag + * in the ntfs volume @vol. + * + * NOTE: We always perform synchronous i/o and ignore the @sync parameter. + * + * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just + * schedule i/o via ->writepage or do it via kntfsd or whatever. + */ +int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no, + MFT_RECORD *m, int sync) +{ + struct page *page; + unsigned int blocksize = vol->sb->s_blocksize; + int max_bhs = vol->mft_record_size / blocksize; + struct buffer_head *bhs[max_bhs]; + struct buffer_head *bh, *head; + u8 *kmirr; + runlist_element *rl; + unsigned int block_start, block_end, m_start, m_end, page_ofs; + int i_bhs, nr_bhs, err = 0; + unsigned char blocksize_bits = vol->mftmirr_ino->i_blkbits; + + ntfs_debug("Entering for inode 0x%lx.", mft_no); + BUG_ON(!max_bhs); + if (unlikely(!vol->mftmirr_ino)) { + /* This could happen during umount... */ + err = ntfs_sync_mft_mirror_umount(vol, mft_no, m); + if (likely(!err)) + return err; + goto err_out; + } + /* Get the page containing the mirror copy of the mft record @m. */ + page = ntfs_map_page(vol->mftmirr_ino->i_mapping, mft_no >> + (PAGE_CACHE_SHIFT - vol->mft_record_size_bits)); + if (IS_ERR(page)) { + ntfs_error(vol->sb, "Failed to map mft mirror page."); + err = PTR_ERR(page); + goto err_out; + } + lock_page(page); + BUG_ON(!PageUptodate(page)); + ClearPageUptodate(page); + /* Offset of the mft mirror record inside the page. */ + page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; + /* The address in the page of the mirror copy of the mft record @m. */ + kmirr = page_address(page) + page_ofs; + /* Copy the mst protected mft record to the mirror. */ + memcpy(kmirr, m, vol->mft_record_size); + /* Create uptodate buffers if not present. */ + if (unlikely(!page_has_buffers(page))) { + struct buffer_head *tail; + + bh = head = alloc_page_buffers(page, blocksize, 1); + do { + set_buffer_uptodate(bh); + tail = bh; + bh = bh->b_this_page; + } while (bh); + tail->b_this_page = head; + attach_page_buffers(page, head); + BUG_ON(!page_has_buffers(page)); + } + bh = head = page_buffers(page); + BUG_ON(!bh); + rl = NULL; + nr_bhs = 0; + block_start = 0; + m_start = kmirr - (u8*)page_address(page); + m_end = m_start + vol->mft_record_size; + do { + block_end = block_start + blocksize; + /* If the buffer is outside the mft record, skip it. */ + if (block_end <= m_start) + continue; + if (unlikely(block_start >= m_end)) + break; + /* Need to map the buffer if it is not mapped already. */ + if (unlikely(!buffer_mapped(bh))) { + VCN vcn; + LCN lcn; + unsigned int vcn_ofs; + + /* Obtain the vcn and offset of the current block. */ + vcn = ((VCN)mft_no << vol->mft_record_size_bits) + + (block_start - m_start); + vcn_ofs = vcn & vol->cluster_size_mask; + vcn >>= vol->cluster_size_bits; + if (!rl) { + down_read(&NTFS_I(vol->mftmirr_ino)-> + runlist.lock); + rl = NTFS_I(vol->mftmirr_ino)->runlist.rl; + /* + * $MFTMirr always has the whole of its runlist + * in memory. + */ + BUG_ON(!rl); + } + /* Seek to element containing target vcn. */ + while (rl->length && rl[1].vcn <= vcn) + rl++; + lcn = ntfs_rl_vcn_to_lcn(rl, vcn); + /* For $MFTMirr, only lcn >= 0 is a successful remap. */ + if (likely(lcn >= 0)) { + /* Setup buffer head to correct block. */ + bh->b_blocknr = ((lcn << + vol->cluster_size_bits) + + vcn_ofs) >> blocksize_bits; + set_buffer_mapped(bh); + } else { + bh->b_blocknr = -1; + ntfs_error(vol->sb, "Cannot write mft mirror " + "record 0x%lx because its " + "location on disk could not " + "be determined (error code " + "%lli).", mft_no, + (long long)lcn); + err = -EIO; + } + } + BUG_ON(!buffer_uptodate(bh)); + BUG_ON(!nr_bhs && (m_start != block_start)); + BUG_ON(nr_bhs >= max_bhs); + bhs[nr_bhs++] = bh; + BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end)); + } while (block_start = block_end, (bh = bh->b_this_page) != head); + if (unlikely(rl)) + up_read(&NTFS_I(vol->mftmirr_ino)->runlist.lock); + if (likely(!err)) { + /* Lock buffers and start synchronous write i/o on them. */ + for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { + struct buffer_head *tbh = bhs[i_bhs]; + + if (unlikely(test_set_buffer_locked(tbh))) + BUG(); + BUG_ON(!buffer_uptodate(tbh)); + clear_buffer_dirty(tbh); + get_bh(tbh); + tbh->b_end_io = end_buffer_write_sync; + submit_bh(WRITE, tbh); + } + /* Wait on i/o completion of buffers. */ + for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { + struct buffer_head *tbh = bhs[i_bhs]; + + wait_on_buffer(tbh); + if (unlikely(!buffer_uptodate(tbh))) { + err = -EIO; + /* + * Set the buffer uptodate so the page and + * buffer states do not become out of sync. + */ + set_buffer_uptodate(tbh); + } + } + } else /* if (unlikely(err)) */ { + /* Clean the buffers. */ + for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) + clear_buffer_dirty(bhs[i_bhs]); + } + /* Current state: all buffers are clean, unlocked, and uptodate. */ + /* Remove the mst protection fixups again. */ + post_write_mst_fixup((NTFS_RECORD*)kmirr); + flush_dcache_page(page); + SetPageUptodate(page); + unlock_page(page); + ntfs_unmap_page(page); + if (likely(!err)) { + ntfs_debug("Done."); + } else { + ntfs_error(vol->sb, "I/O error while writing mft mirror " + "record 0x%lx!", mft_no); +err_out: + ntfs_error(vol->sb, "Failed to synchronize $MFTMirr (error " + "code %i). Volume will be left marked dirty " + "on umount. Run ntfsfix on the partition " + "after umounting to correct this.", -err); + NVolSetErrors(vol); + } + return err; +} + +/** + * write_mft_record_nolock - write out a mapped (extent) mft record + * @ni: ntfs inode describing the mapped (extent) mft record + * @m: mapped (extent) mft record to write + * @sync: if true, wait for i/o completion + * + * Write the mapped (extent) mft record @m described by the (regular or extent) + * ntfs inode @ni to backing store. If the mft record @m has a counterpart in + * the mft mirror, that is also updated. + * + * We only write the mft record if the ntfs inode @ni is dirty and the first + * buffer belonging to its mft record is dirty, too. We ignore the dirty state + * of subsequent buffers because we could have raced with + * fs/ntfs/aops.c::mark_ntfs_record_dirty(). + * + * On success, clean the mft record and return 0. On error, leave the mft + * record dirty and return -errno. The caller should call make_bad_inode() on + * the base inode to ensure no more access happens to this inode. We do not do + * it here as the caller may want to finish writing other extent mft records + * first to minimize on-disk metadata inconsistencies. + * + * NOTE: We always perform synchronous i/o and ignore the @sync parameter. + * However, if the mft record has a counterpart in the mft mirror and @sync is + * true, we write the mft record, wait for i/o completion, and only then write + * the mft mirror copy. This ensures that if the system crashes either the mft + * or the mft mirror will contain a self-consistent mft record @m. If @sync is + * false on the other hand, we start i/o on both and then wait for completion + * on them. This provides a speedup but no longer guarantees that you will end + * up with a self-consistent mft record in the case of a crash but if you asked + * for asynchronous writing you probably do not care about that anyway. + * + * TODO: If @sync is false, want to do truly asynchronous i/o, i.e. just + * schedule i/o via ->writepage or do it via kntfsd or whatever. + */ +int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync) +{ + ntfs_volume *vol = ni->vol; + struct page *page = ni->page; + unsigned char blocksize_bits = vol->mft_ino->i_blkbits; + unsigned int blocksize = 1 << blocksize_bits; + int max_bhs = vol->mft_record_size / blocksize; + struct buffer_head *bhs[max_bhs]; + struct buffer_head *bh, *head; + runlist_element *rl; + unsigned int block_start, block_end, m_start, m_end; + int i_bhs, nr_bhs, err = 0; + + ntfs_debug("Entering for inode 0x%lx.", ni->mft_no); + BUG_ON(NInoAttr(ni)); + BUG_ON(!max_bhs); + BUG_ON(!PageLocked(page)); + /* + * If the ntfs_inode is clean no need to do anything. If it is dirty, + * mark it as clean now so that it can be redirtied later on if needed. + * There is no danger of races since the caller is holding the locks + * for the mft record @m and the page it is in. + */ + if (!NInoTestClearDirty(ni)) + goto done; + BUG_ON(!page_has_buffers(page)); + bh = head = page_buffers(page); + BUG_ON(!bh); + rl = NULL; + nr_bhs = 0; + block_start = 0; + m_start = ni->page_ofs; + m_end = m_start + vol->mft_record_size; + do { + block_end = block_start + blocksize; + /* If the buffer is outside the mft record, skip it. */ + if (block_end <= m_start) + continue; + if (unlikely(block_start >= m_end)) + break; + /* + * If 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 (block_start == m_start) { + /* This block is the first one in the record. */ + if (!buffer_dirty(bh)) { + BUG_ON(nr_bhs); + /* Clean records are not written out. */ + break; + } + } + /* Need to map the buffer if it is not mapped already. */ + if (unlikely(!buffer_mapped(bh))) { + VCN vcn; + LCN lcn; + unsigned int vcn_ofs; + + /* Obtain the vcn and offset of the current block. */ + vcn = ((VCN)ni->mft_no << vol->mft_record_size_bits) + + (block_start - m_start); + vcn_ofs = vcn & vol->cluster_size_mask; + vcn >>= vol->cluster_size_bits; + if (!rl) { + down_read(&NTFS_I(vol->mft_ino)->runlist.lock); + rl = NTFS_I(vol->mft_ino)->runlist.rl; + BUG_ON(!rl); + } + /* Seek to element containing target vcn. */ + while (rl->length && rl[1].vcn <= vcn) + rl++; + lcn = ntfs_rl_vcn_to_lcn(rl, vcn); + /* For $MFT, only lcn >= 0 is a successful remap. */ + if (likely(lcn >= 0)) { + /* Setup buffer head to correct block. */ + bh->b_blocknr = ((lcn << + vol->cluster_size_bits) + + vcn_ofs) >> blocksize_bits; + set_buffer_mapped(bh); + } else { + bh->b_blocknr = -1; + ntfs_error(vol->sb, "Cannot write mft record " + "0x%lx because its location " + "on disk could not be " + "determined (error code %lli).", + ni->mft_no, (long long)lcn); + err = -EIO; + } + } + BUG_ON(!buffer_uptodate(bh)); + BUG_ON(!nr_bhs && (m_start != block_start)); + BUG_ON(nr_bhs >= max_bhs); + bhs[nr_bhs++] = bh; + BUG_ON((nr_bhs >= max_bhs) && (m_end != block_end)); + } while (block_start = block_end, (bh = bh->b_this_page) != head); + if (unlikely(rl)) + up_read(&NTFS_I(vol->mft_ino)->runlist.lock); + if (!nr_bhs) + goto done; + if (unlikely(err)) + goto cleanup_out; + /* Apply the mst protection fixups. */ + err = pre_write_mst_fixup((NTFS_RECORD*)m, vol->mft_record_size); + if (err) { + ntfs_error(vol->sb, "Failed to apply mst fixups!"); + goto cleanup_out; + } + flush_dcache_mft_record_page(ni); + /* Lock buffers and start synchronous write i/o on them. */ + for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { + struct buffer_head *tbh = bhs[i_bhs]; + + if (unlikely(test_set_buffer_locked(tbh))) + BUG(); + BUG_ON(!buffer_uptodate(tbh)); + clear_buffer_dirty(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 (!sync && ni->mft_no < vol->mftmirr_size) + ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync); + /* Wait on i/o completion of buffers. */ + for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) { + struct buffer_head *tbh = bhs[i_bhs]; + + wait_on_buffer(tbh); + if (unlikely(!buffer_uptodate(tbh))) { + err = -EIO; + /* + * Set the buffer uptodate so the page and buffer + * states do not become out of sync. + */ + if (PageUptodate(page)) + set_buffer_uptodate(tbh); + } + } + /* If @sync, now synchronize the mft mirror. */ + if (sync && ni->mft_no < vol->mftmirr_size) + ntfs_sync_mft_mirror(vol, ni->mft_no, m, sync); + /* Remove the mst protection fixups again. */ + post_write_mst_fixup((NTFS_RECORD*)m); + flush_dcache_mft_record_page(ni); + if (unlikely(err)) { + /* I/O error during writing. This is really bad! */ + ntfs_error(vol->sb, "I/O error while writing mft record " + "0x%lx! Marking base inode as bad. You " + "should unmount the volume and run chkdsk.", + ni->mft_no); + goto err_out; + } +done: + ntfs_debug("Done."); + return 0; +cleanup_out: + /* Clean the buffers. */ + for (i_bhs = 0; i_bhs < nr_bhs; i_bhs++) + clear_buffer_dirty(bhs[i_bhs]); +err_out: + /* + * Current state: all buffers are clean, unlocked, and uptodate. + * The caller should mark the base inode as bad so that no more i/o + * happens. ->clear_inode() will still be invoked so all extent inodes + * and other allocated memory will be freed. + */ + if (err == -ENOMEM) { + ntfs_error(vol->sb, "Not enough memory to write mft record. " + "Redirtying so the write is retried later."); + mark_mft_record_dirty(ni); + err = 0; + } else + NVolSetErrors(vol); + return err; +} + +/** + * ntfs_may_write_mft_record - check if an mft record may be written out + * @vol: [IN] ntfs volume on which the mft record to check resides + * @mft_no: [IN] mft record number of the mft record to check + * @m: [IN] mapped mft record to check + * @locked_ni: [OUT] caller has to unlock this ntfs inode if one is returned + * + * Check if the mapped (base or extent) mft record @m with mft record number + * @mft_no belonging to the ntfs volume @vol may be written out. If necessary + * and possible the ntfs inode of the mft record is locked and the base vfs + * inode is pinned. The locked ntfs inode is then returned in @locked_ni. The + * caller is responsible for unlocking the ntfs inode and unpinning the base + * vfs inode. + * + * Return TRUE if the mft record may be written out and FALSE if not. + * + * The caller has locked the page and cleared the uptodate flag on it which + * means that we can safely write out any dirty mft records that do not have + * their inodes in icache as determined by ilookup5() as anyone + * opening/creating such an inode would block when attempting to map the mft + * record in read_cache_page() until we are finished with the write out. + * + * Here is a description of the tests we perform: + * + * If the inode is found in icache we know the mft record must be a base mft + * record. If it is dirty, we do not write it and return FALSE as the vfs + * inode write paths will result in the access times being updated which would + * cause the base mft record to be redirtied and written out again. (We know + * the access time update will modify the base mft record because Windows + * chkdsk complains if the standard information attribute is not in the base + * mft record.) + * + * If the inode is in icache and not dirty, we attempt to lock the mft record + * and if we find the lock was already taken, it is not safe to write the mft + * record and we return FALSE. + * + * If we manage to obtain the lock we have exclusive access to the mft record, + * which also allows us safe writeout of the mft record. We then set + * @locked_ni to the locked ntfs inode and return TRUE. + * + * Note we cannot just lock the mft record and sleep while waiting for the lock + * because this would deadlock due to lock reversal (normally the mft record is + * locked before the page is locked but we already have the page locked here + * when we try to lock the mft record). + * + * If the inode is not in icache we need to perform further checks. + * + * If the mft record is not a FILE record or it is a base mft record, we can + * safely write it and return TRUE. + * + * We now know the mft record is an extent mft record. We check if the inode + * corresponding to its base mft record is in icache and obtain a reference to + * it if it is. If it is not, we can safely write it and return TRUE. + * + * We now have the base inode for the extent mft record. We check if it has an + * ntfs inode for the extent mft record attached and if not it is safe to write + * the extent mft record and we return TRUE. + * + * The ntfs inode for the extent mft record is attached to the base inode so we + * attempt to lock the extent mft record and if we find the lock was already + * taken, it is not safe to write the extent mft record and we return FALSE. + * + * If we manage to obtain the lock we have exclusive access to the extent mft + * record, which also allows us safe writeout of the extent mft record. We + * set the ntfs inode of the extent mft record clean and then set @locked_ni to + * the now locked ntfs inode and return TRUE. + * + * Note, the reason for actually writing dirty mft records here and not just + * relying on the vfs inode dirty code paths is that we can have mft records + * modified without them ever having actual inodes in memory. Also we can have + * dirty mft records with clean ntfs inodes in memory. None of the described + * cases would result in the dirty mft records being written out if we only + * relied on the vfs inode dirty code paths. And these cases can really occur + * during allocation of new mft records and in particular when the + * initialized_size of the $MFT/$DATA attribute is extended and the new space + * is initialized using ntfs_mft_record_format(). The clean inode can then + * appear if the mft record is reused for a new inode before it got written + * out. + */ +BOOL ntfs_may_write_mft_record(ntfs_volume *vol, const unsigned long mft_no, + const MFT_RECORD *m, ntfs_inode **locked_ni) +{ + struct super_block *sb = vol->sb; + struct inode *mft_vi = vol->mft_ino; + struct inode *vi; + ntfs_inode *ni, *eni, **extent_nis; + int i; + ntfs_attr na; + + ntfs_debug("Entering for inode 0x%lx.", mft_no); + /* + * Normally we do not return a locked inode so set @locked_ni to NULL. + */ + BUG_ON(!locked_ni); + *locked_ni = NULL; + /* + * Check if the inode corresponding to this mft record is in the VFS + * inode cache and obtain a reference to it if it is. + */ + ntfs_debug("Looking for inode 0x%lx in icache.", mft_no); + na.mft_no = mft_no; + na.name = NULL; + na.name_len = 0; + na.type = AT_UNUSED; + /* + * For inode 0, i.e. $MFT itself, we cannot use ilookup5() from here or + * we deadlock because the inode is already locked by the kernel + * (fs/fs-writeback.c::__sync_single_inode()) and ilookup5() waits + * until the inode is unlocked before returning it and it never gets + * unlocked because ntfs_should_write_mft_record() never returns. )-: + * Fortunately, we have inode 0 pinned in icache for the duration of + * the mount so we can access it directly. + */ + if (!mft_no) { + /* Balance the below iput(). */ + vi = igrab(mft_vi); + BUG_ON(vi != mft_vi); + } else + vi = ilookup5(sb, mft_no, (test_t)ntfs_test_inode, &na); + if (vi) { + ntfs_debug("Base inode 0x%lx is in icache.", mft_no); + /* The inode is in icache. */ + ni = NTFS_I(vi); + /* Take a reference to the ntfs inode. */ + atomic_inc(&ni->count); + /* If the inode is dirty, do not write this record. */ + if (NInoDirty(ni)) { + ntfs_debug("Inode 0x%lx is dirty, do not write it.", + mft_no); + atomic_dec(&ni->count); + iput(vi); + return FALSE; + } + ntfs_debug("Inode 0x%lx is not dirty.", mft_no); + /* The inode is not dirty, try to take the mft record lock. */ + if (unlikely(down_trylock(&ni->mrec_lock))) { + ntfs_debug("Mft record 0x%lx is already locked, do " + "not write it.", mft_no); + atomic_dec(&ni->count); + iput(vi); + return FALSE; + } + ntfs_debug("Managed to lock mft record 0x%lx, write it.", + mft_no); + /* + * The write has to occur while we hold the mft record lock so + * return the locked ntfs inode. + */ + *locked_ni = ni; + return TRUE; + } + ntfs_debug("Inode 0x%lx is not in icache.", mft_no); + /* The inode is not in icache. */ + /* Write the record if it is not a mft record (type "FILE"). */ + if (!ntfs_is_mft_record(m->magic)) { + ntfs_debug("Mft record 0x%lx is not a FILE record, write it.", + mft_no); + return TRUE; + } + /* Write the mft record if it is a base inode. */ + if (!m->base_mft_record) { + ntfs_debug("Mft record 0x%lx is a base record, write it.", + mft_no); + return TRUE; + } + /* + * This is an extent mft record. Check if the inode corresponding to + * its base mft record is in icache and obtain a reference to it if it + * is. + */ + na.mft_no = MREF_LE(m->base_mft_record); + ntfs_debug("Mft record 0x%lx is an extent record. Looking for base " + "inode 0x%lx in icache.", mft_no, na.mft_no); + vi = ilookup5(sb, na.mft_no, (test_t)ntfs_test_inode, &na); + if (!vi) { + /* + * The base inode is not in icache, write this extent mft + * record. + */ + ntfs_debug("Base inode 0x%lx is not in icache, write the " + "extent record.", na.mft_no); + return TRUE; + } + ntfs_debug("Base inode 0x%lx is in icache.", na.mft_no); + /* + * The base inode is in icache. Check if it has the extent inode + * corresponding to this extent mft record attached. + */ + ni = NTFS_I(vi); + down(&ni->extent_lock); + if (ni->nr_extents <= 0) { + /* + * The base inode has no attached extent inodes, write this + * extent mft record. + */ + up(&ni->extent_lock); + iput(vi); + ntfs_debug("Base inode 0x%lx has no attached extent inodes, " + "write the extent record.", na.mft_no); + return TRUE; + } + /* Iterate over the attached extent inodes. */ + extent_nis = ni->ext.extent_ntfs_inos; + for (eni = NULL, i = 0; i < ni->nr_extents; ++i) { + if (mft_no == extent_nis[i]->mft_no) { + /* + * Found the extent inode corresponding to this extent + * mft record. + */ + eni = extent_nis[i]; + break; + } + } + /* + * If the extent inode was not attached to the base inode, write this + * extent mft record. + */ + if (!eni) { + up(&ni->extent_lock); + iput(vi); + ntfs_debug("Extent inode 0x%lx is not attached to its base " + "inode 0x%lx, write the extent record.", + mft_no, na.mft_no); + return TRUE; + } + ntfs_debug("Extent inode 0x%lx is attached to its base inode 0x%lx.", + mft_no, na.mft_no); + /* Take a reference to the extent ntfs inode. */ + atomic_inc(&eni->count); + up(&ni->extent_lock); + /* + * Found the extent inode coresponding to this extent mft record. + * Try to take the mft record lock. + */ + if (unlikely(down_trylock(&eni->mrec_lock))) { + atomic_dec(&eni->count); + iput(vi); + ntfs_debug("Extent mft record 0x%lx is already locked, do " + "not write it.", mft_no); + return FALSE; + } + ntfs_debug("Managed to lock extent mft record 0x%lx, write it.", + mft_no); + if (NInoTestClearDirty(eni)) + ntfs_debug("Extent inode 0x%lx is dirty, marking it clean.", + mft_no); + /* + * The write has to occur while we hold the mft record lock so return + * the locked extent ntfs inode. + */ + *locked_ni = eni; + return TRUE; +} + +static const char *es = " Leaving inconsistent metadata. Unmount and run " + "chkdsk."; + +/** + * ntfs_mft_bitmap_find_and_alloc_free_rec_nolock - see name + * @vol: volume on which to search for a free mft record + * @base_ni: open base inode if allocating an extent mft record or NULL + * + * Search for a free mft record in the mft bitmap attribute on the ntfs volume + * @vol. + * + * If @base_ni is NULL start the search at the default allocator position. + * + * If @base_ni is not NULL start the search at the mft record after the base + * mft record @base_ni. + * + * Return the free mft record on success and -errno on error. An error code of + * -ENOSPC means that there are no free mft records in the currently + * initialized mft bitmap. + * + * Locking: Caller must hold vol->mftbmp_lock for writing. + */ +static int ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(ntfs_volume *vol, + ntfs_inode *base_ni) +{ + s64 pass_end, ll, data_pos, pass_start, ofs, bit; + struct address_space *mftbmp_mapping; + u8 *buf, *byte; + struct page *page; + unsigned int page_ofs, size; + u8 pass, b; + + ntfs_debug("Searching for free mft record in the currently " + "initialized mft bitmap."); + mftbmp_mapping = vol->mftbmp_ino->i_mapping; + /* + * Set the end of the pass making sure we do not overflow the mft + * bitmap. + */ + pass_end = NTFS_I(vol->mft_ino)->allocated_size >> + vol->mft_record_size_bits; + ll = NTFS_I(vol->mftbmp_ino)->initialized_size << 3; + if (pass_end > ll) + pass_end = ll; + pass = 1; + if (!base_ni) + data_pos = vol->mft_data_pos; + else + data_pos = base_ni->mft_no + 1; + if (data_pos < 24) + data_pos = 24; + if (data_pos >= pass_end) { + data_pos = 24; + pass = 2; + /* This happens on a freshly formatted volume. */ + if (data_pos >= pass_end) + return -ENOSPC; + } + pass_start = data_pos; + ntfs_debug("Starting bitmap search: pass %u, pass_start 0x%llx, " + "pass_end 0x%llx, data_pos 0x%llx.", pass, + (long long)pass_start, (long long)pass_end, + (long long)data_pos); + /* Loop until a free mft record is found. */ + for (; pass <= 2;) { + /* Cap size to pass_end. */ + ofs = data_pos >> 3; + page_ofs = ofs & ~PAGE_CACHE_MASK; + size = PAGE_CACHE_SIZE - page_ofs; + ll = ((pass_end + 7) >> 3) - ofs; + if (size > ll) + size = ll; + size <<= 3; + /* + * If we are still within the active pass, search the next page + * for a zero bit. + */ + if (size) { + page = ntfs_map_page(mftbmp_mapping, + ofs >> PAGE_CACHE_SHIFT); + if (unlikely(IS_ERR(page))) { + ntfs_error(vol->sb, "Failed to read mft " + "bitmap, aborting."); + return PTR_ERR(page); + } + buf = (u8*)page_address(page) + page_ofs; + bit = data_pos & 7; + data_pos &= ~7ull; + ntfs_debug("Before inner for loop: size 0x%x, " + "data_pos 0x%llx, bit 0x%llx", size, + (long long)data_pos, (long long)bit); + for (; bit < size && data_pos + bit < pass_end; + bit &= ~7ull, bit += 8) { + byte = buf + (bit >> 3); + if (*byte == 0xff) + continue; + b = ffz((unsigned long)*byte); + if (b < 8 && b >= (bit & 7)) { + ll = data_pos + (bit & ~7ull) + b; + if (unlikely(ll > (1ll << 32))) { + ntfs_unmap_page(page); + return -ENOSPC; + } + *byte |= 1 << b; + flush_dcache_page(page); + set_page_dirty(page); + ntfs_unmap_page(page); + ntfs_debug("Done. (Found and " + "allocated mft record " + "0x%llx.)", + (long long)ll); + return ll; + } + } + ntfs_debug("After inner for loop: size 0x%x, " + "data_pos 0x%llx, bit 0x%llx", size, + (long long)data_pos, (long long)bit); + data_pos += size; + ntfs_unmap_page(page); + /* + * If the end of the pass has not been reached yet, + * continue searching the mft bitmap for a zero bit. + */ + if (data_pos < pass_end) + continue; + } + /* Do the next pass. */ + if (++pass == 2) { + /* + * Starting the second pass, in which we scan the first + * part of the zone which we omitted earlier. + */ + pass_end = pass_start; + data_pos = pass_start = 24; + ntfs_debug("pass %i, pass_start 0x%llx, pass_end " + "0x%llx.", pass, (long long)pass_start, + (long long)pass_end); + if (data_pos >= pass_end) + break; + } + } + /* No free mft records in currently initialized mft bitmap. */ + ntfs_debug("Done. (No free mft records left in currently initialized " + "mft bitmap.)"); + return -ENOSPC; +} + +/** + * ntfs_mft_bitmap_extend_allocation_nolock - extend mft bitmap by a cluster + * @vol: volume on which to extend the mft bitmap attribute + * + * Extend the mft bitmap attribute on the ntfs volume @vol by one cluster. + * + * Note: Only changes allocated_size, i.e. does not touch initialized_size or + * data_size. + * + * Return 0 on success and -errno on error. + * + * Locking: - Caller must hold vol->mftbmp_lock for writing. + * - This function takes NTFS_I(vol->mftbmp_ino)->runlist.lock for + * writing and releases it before returning. + * - This function takes vol->lcnbmp_lock for writing and releases it + * before returning. + */ +static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol) +{ + LCN lcn; + s64 ll; + struct page *page; + ntfs_inode *mft_ni, *mftbmp_ni; + runlist_element *rl, *rl2 = NULL; + ntfs_attr_search_ctx *ctx = NULL; + MFT_RECORD *mrec; + ATTR_RECORD *a = NULL; + int ret, mp_size; + u32 old_alen = 0; + u8 *b, tb; + struct { + u8 added_cluster:1; + u8 added_run:1; + u8 mp_rebuilt:1; + } status = { 0, 0, 0 }; + + ntfs_debug("Extending mft bitmap allocation."); + mft_ni = NTFS_I(vol->mft_ino); + mftbmp_ni = NTFS_I(vol->mftbmp_ino); + /* + * Determine the last lcn of the mft bitmap. The allocated size of the + * mft bitmap cannot be zero so we are ok to do this. + * ntfs_find_vcn() returns the runlist locked on success. + */ + rl = ntfs_find_vcn(mftbmp_ni, (mftbmp_ni->allocated_size - 1) >> + vol->cluster_size_bits, TRUE); + if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { + ntfs_error(vol->sb, "Failed to determine last allocated " + "cluster of mft bitmap attribute."); + if (!IS_ERR(rl)) { + up_write(&mftbmp_ni->runlist.lock); + ret = -EIO; + } else + ret = PTR_ERR(rl); + return ret; + } + lcn = rl->lcn + rl->length; + ntfs_debug("Last lcn of mft bitmap attribute is 0x%llx.", + (long long)lcn); + /* + * Attempt to get the cluster following the last allocated cluster by + * hand as it may be in the MFT zone so the allocator would not give it + * to us. + */ + ll = lcn >> 3; + page = ntfs_map_page(vol->lcnbmp_ino->i_mapping, + ll >> PAGE_CACHE_SHIFT); + if (IS_ERR(page)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to read from lcn bitmap."); + return PTR_ERR(page); + } + b = (u8*)page_address(page) + (ll & ~PAGE_CACHE_MASK); + tb = 1 << (lcn & 7ull); + down_write(&vol->lcnbmp_lock); + if (*b != 0xff && !(*b & tb)) { + /* Next cluster is free, allocate it. */ + *b |= tb; + flush_dcache_page(page); + set_page_dirty(page); + up_write(&vol->lcnbmp_lock); + ntfs_unmap_page(page); + /* Update the mft bitmap runlist. */ + rl->length++; + rl[1].vcn++; + status.added_cluster = 1; + ntfs_debug("Appending one cluster to mft bitmap."); + } else { + up_write(&vol->lcnbmp_lock); + ntfs_unmap_page(page); + /* Allocate a cluster from the DATA_ZONE. */ + rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE); + if (IS_ERR(rl2)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to allocate a cluster for " + "the mft bitmap."); + return PTR_ERR(rl2); + } + rl = ntfs_runlists_merge(mftbmp_ni->runlist.rl, rl2); + if (IS_ERR(rl)) { + up_write(&mftbmp_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to merge runlists for mft " + "bitmap."); + if (ntfs_cluster_free_from_rl(vol, rl2)) { + ntfs_error(vol->sb, "Failed to dealocate " + "allocated cluster.%s", es); + NVolSetErrors(vol); + } + ntfs_free(rl2); + return PTR_ERR(rl); + } + mftbmp_ni->runlist.rl = rl; + status.added_run = 1; + ntfs_debug("Adding one run to mft bitmap."); + /* Find the last run in the new runlist. */ + for (; rl[1].length; rl++) + ; + } + /* + * Update the attribute record as well. Note: @rl is the last + * (non-terminator) runlist element of mft bitmap. + */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record."); + ret = PTR_ERR(mrec); + goto undo_alloc; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + ret = -ENOMEM; + goto undo_alloc; + } + ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, + 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to find last attribute extent of " + "mft bitmap attribute."); + if (ret == -ENOENT) + ret = -EIO; + goto undo_alloc; + } + a = ctx->attr; + ll = sle64_to_cpu(a->data.non_resident.lowest_vcn); + /* Search back for the previous last allocated cluster of mft bitmap. */ + for (rl2 = rl; rl2 > mftbmp_ni->runlist.rl; rl2--) { + if (ll >= rl2->vcn) + break; + } + BUG_ON(ll < rl2->vcn); + BUG_ON(ll >= rl2->vcn + rl2->length); + /* Get the size for the new mapping pairs array for this extent. */ + mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll); + if (unlikely(mp_size <= 0)) { + ntfs_error(vol->sb, "Get size for mapping pairs failed for " + "mft bitmap attribute extent."); + ret = mp_size; + if (!ret) + ret = -EIO; + goto undo_alloc; + } + /* Expand the attribute record if necessary. */ + old_alen = le32_to_cpu(a->length); + ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); + if (unlikely(ret)) { + if (ret != -ENOSPC) { + ntfs_error(vol->sb, "Failed to resize attribute " + "record for mft bitmap attribute."); + goto undo_alloc; + } + // TODO: Deal with this by moving this extent to a new mft + // record or by starting a new extent in a new mft record or by + // moving other attributes out of this mft record. + ntfs_error(vol->sb, "Not enough space in this mft record to " + "accomodate extended mft bitmap attribute " + "extent. Cannot handle this yet."); + ret = -EOPNOTSUPP; + goto undo_alloc; + } + status.mp_rebuilt = 1; + /* Generate the mapping pairs array directly into the attr record. */ + ret = ntfs_mapping_pairs_build(vol, (u8*)a + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset), + mp_size, rl2, ll, NULL); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to build mapping pairs array for " + "mft bitmap attribute."); + goto undo_alloc; + } + /* Update the highest_vcn. */ + a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1); + /* + * We now have extended the mft bitmap allocated_size by one cluster. + * Reflect this in the ntfs_inode structure and the attribute record. + */ + if (a->data.non_resident.lowest_vcn) { + /* + * We are not in the first attribute extent, switch to it, but + * first ensure the changes will make it to disk later. + */ + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_reinit_search_ctx(ctx); + ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, + 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to find first attribute " + "extent of mft bitmap attribute."); + goto restore_undo_alloc; + } + a = ctx->attr; + } + mftbmp_ni->allocated_size += vol->cluster_size; + a->data.non_resident.allocated_size = + cpu_to_sle64(mftbmp_ni->allocated_size); + /* 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(mft_ni); + up_write(&mftbmp_ni->runlist.lock); + ntfs_debug("Done."); + return 0; +restore_undo_alloc: + ntfs_attr_reinit_search_ctx(ctx); + if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, rl[1].vcn, NULL, + 0, ctx)) { + ntfs_error(vol->sb, "Failed to find last attribute extent of " + "mft bitmap attribute.%s", es); + mftbmp_ni->allocated_size += vol->cluster_size; + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + up_write(&mftbmp_ni->runlist.lock); + /* + * The only thing that is now wrong is ->allocated_size of the + * base attribute extent which chkdsk should be able to fix. + */ + NVolSetErrors(vol); + return ret; + } + a = ctx->attr; + a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 2); +undo_alloc: + if (status.added_cluster) { + /* Truncate the last run in the runlist by one cluster. */ + rl->length--; + rl[1].vcn--; + } else if (status.added_run) { + lcn = rl->lcn; + /* Remove the last run from the runlist. */ + rl->lcn = rl[1].lcn; + rl->length = 0; + } + /* Deallocate the cluster. */ + down_write(&vol->lcnbmp_lock); + if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) { + ntfs_error(vol->sb, "Failed to free allocated cluster.%s", es); + NVolSetErrors(vol); + } + up_write(&vol->lcnbmp_lock); + if (status.mp_rebuilt) { + if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + old_alen - le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + rl2, ll, NULL)) { + ntfs_error(vol->sb, "Failed to restore mapping pairs " + "array.%s", es); + NVolSetErrors(vol); + } + if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { + ntfs_error(vol->sb, "Failed to restore attribute " + "record.%s", es); + NVolSetErrors(vol); + } + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + } + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (!IS_ERR(mrec)) + unmap_mft_record(mft_ni); + up_write(&mftbmp_ni->runlist.lock); + return ret; +} + +/** + * ntfs_mft_bitmap_extend_initialized_nolock - extend mftbmp initialized data + * @vol: volume on which to extend the mft bitmap attribute + * + * Extend the initialized portion of the mft bitmap attribute on the ntfs + * volume @vol by 8 bytes. + * + * Note: Only changes initialized_size and data_size, i.e. requires that + * allocated_size is big enough to fit the new initialized_size. + * + * Return 0 on success and -error on error. + * + * Locking: Caller must hold vol->mftbmp_lock for writing. + */ +static int ntfs_mft_bitmap_extend_initialized_nolock(ntfs_volume *vol) +{ + s64 old_data_size, old_initialized_size; + struct inode *mftbmp_vi; + ntfs_inode *mft_ni, *mftbmp_ni; + ntfs_attr_search_ctx *ctx; + MFT_RECORD *mrec; + ATTR_RECORD *a; + int ret; + + ntfs_debug("Extending mft bitmap initiailized (and data) size."); + mft_ni = NTFS_I(vol->mft_ino); + mftbmp_vi = vol->mftbmp_ino; + mftbmp_ni = NTFS_I(mftbmp_vi); + /* Get the attribute record. */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record."); + return PTR_ERR(mrec); + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + ret = -ENOMEM; + goto unm_err_out; + } + ret = ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to find first attribute extent of " + "mft bitmap attribute."); + if (ret == -ENOENT) + ret = -EIO; + goto put_err_out; + } + a = ctx->attr; + old_data_size = mftbmp_vi->i_size; + old_initialized_size = mftbmp_ni->initialized_size; + /* + * We can simply update the initialized_size before filling the space + * with zeroes because the caller is holding the mft bitmap lock for + * writing which ensures that no one else is trying to access the data. + */ + mftbmp_ni->initialized_size += 8; + a->data.non_resident.initialized_size = + cpu_to_sle64(mftbmp_ni->initialized_size); + if (mftbmp_ni->initialized_size > mftbmp_vi->i_size) { + mftbmp_vi->i_size = mftbmp_ni->initialized_size; + a->data.non_resident.data_size = + cpu_to_sle64(mftbmp_vi->i_size); + } + /* 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(mft_ni); + /* Initialize the mft bitmap attribute value with zeroes. */ + ret = ntfs_attr_set(mftbmp_ni, old_initialized_size, 8, 0); + if (likely(!ret)) { + ntfs_debug("Done. (Wrote eight initialized bytes to mft " + "bitmap."); + return 0; + } + ntfs_error(vol->sb, "Failed to write to mft bitmap."); + /* Try to recover from the error. */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record.%s", es); + NVolSetErrors(vol); + return ret; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context.%s", es); + NVolSetErrors(vol); + goto unm_err_out; + } + if (ntfs_attr_lookup(mftbmp_ni->type, mftbmp_ni->name, + mftbmp_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx)) { + ntfs_error(vol->sb, "Failed to find first attribute extent of " + "mft bitmap attribute.%s", es); + NVolSetErrors(vol); +put_err_out: + ntfs_attr_put_search_ctx(ctx); +unm_err_out: + unmap_mft_record(mft_ni); + goto err_out; + } + a = ctx->attr; + mftbmp_ni->initialized_size = old_initialized_size; + a->data.non_resident.initialized_size = + cpu_to_sle64(old_initialized_size); + if (mftbmp_vi->i_size != old_data_size) { + mftbmp_vi->i_size = old_data_size; + a->data.non_resident.data_size = cpu_to_sle64(old_data_size); + } + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + ntfs_debug("Restored status of mftbmp: allocated_size 0x%llx, " + "data_size 0x%llx, initialized_size 0x%llx.", + (long long)mftbmp_ni->allocated_size, + (long long)mftbmp_vi->i_size, + (long long)mftbmp_ni->initialized_size); +err_out: + return ret; +} + +/** + * ntfs_mft_data_extend_allocation_nolock - extend mft data attribute + * @vol: volume on which to extend the mft data attribute + * + * Extend the mft data attribute on the ntfs volume @vol by 16 mft records + * worth of clusters or if not enough space for this by one mft record worth + * of clusters. + * + * Note: Only changes allocated_size, i.e. does not touch initialized_size or + * data_size. + * + * Return 0 on success and -errno on error. + * + * Locking: - Caller must hold vol->mftbmp_lock for writing. + * - This function takes NTFS_I(vol->mft_ino)->runlist.lock for + * writing and releases it before returning. + * - This function calls functions which take vol->lcnbmp_lock for + * writing and release it before returning. + */ +static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol) +{ + LCN lcn; + VCN old_last_vcn; + s64 min_nr, nr, ll = 0; + ntfs_inode *mft_ni; + runlist_element *rl, *rl2; + ntfs_attr_search_ctx *ctx = NULL; + MFT_RECORD *mrec; + ATTR_RECORD *a = NULL; + int ret, mp_size; + u32 old_alen = 0; + BOOL mp_rebuilt = FALSE; + + ntfs_debug("Extending mft data allocation."); + mft_ni = NTFS_I(vol->mft_ino); + /* + * Determine the preferred allocation location, i.e. the last lcn of + * the mft data attribute. The allocated size of the mft data + * attribute cannot be zero so we are ok to do this. + * ntfs_find_vcn() returns the runlist locked on success. + */ + rl = ntfs_find_vcn(mft_ni, (mft_ni->allocated_size - 1) >> + vol->cluster_size_bits, TRUE); + if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { + ntfs_error(vol->sb, "Failed to determine last allocated " + "cluster of mft data attribute."); + if (!IS_ERR(rl)) { + up_write(&mft_ni->runlist.lock); + ret = -EIO; + } else + ret = PTR_ERR(rl); + return ret; + } + lcn = rl->lcn + rl->length; + ntfs_debug("Last lcn of mft data attribute is 0x%llx.", + (long long)lcn); + /* Minimum allocation is one mft record worth of clusters. */ + min_nr = vol->mft_record_size >> vol->cluster_size_bits; + if (!min_nr) + min_nr = 1; + /* Want to allocate 16 mft records worth of clusters. */ + nr = vol->mft_record_size << 4 >> vol->cluster_size_bits; + if (!nr) + nr = min_nr; + /* Ensure we do not go above 2^32-1 mft records. */ + if (unlikely((mft_ni->allocated_size + + (nr << vol->cluster_size_bits)) >> + vol->mft_record_size_bits >= (1ll << 32))) { + nr = min_nr; + if (unlikely((mft_ni->allocated_size + + (nr << vol->cluster_size_bits)) >> + vol->mft_record_size_bits >= (1ll << 32))) { + ntfs_warning(vol->sb, "Cannot allocate mft record " + "because the maximum number of inodes " + "(2^32) has already been reached."); + up_write(&mft_ni->runlist.lock); + return -ENOSPC; + } + } + ntfs_debug("Trying mft data allocation with %s cluster count %lli.", + nr > min_nr ? "default" : "minimal", (long long)nr); + old_last_vcn = rl[1].vcn; + do { + rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE); + if (likely(!IS_ERR(rl2))) + break; + if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) { + ntfs_error(vol->sb, "Failed to allocate the minimal " + "number of clusters (%lli) for the " + "mft data attribute.", (long long)nr); + up_write(&mft_ni->runlist.lock); + return PTR_ERR(rl2); + } + /* + * There is not enough space to do the allocation, but there + * might be enough space to do a minimal allocation so try that + * before failing. + */ + nr = min_nr; + ntfs_debug("Retrying mft data allocation with minimal cluster " + "count %lli.", (long long)nr); + } while (1); + rl = ntfs_runlists_merge(mft_ni->runlist.rl, rl2); + if (IS_ERR(rl)) { + up_write(&mft_ni->runlist.lock); + ntfs_error(vol->sb, "Failed to merge runlists for mft data " + "attribute."); + if (ntfs_cluster_free_from_rl(vol, rl2)) { + ntfs_error(vol->sb, "Failed to dealocate clusters " + "from the mft data attribute.%s", es); + NVolSetErrors(vol); + } + ntfs_free(rl2); + return PTR_ERR(rl); + } + mft_ni->runlist.rl = rl; + ntfs_debug("Allocated %lli clusters.", nr); + /* Find the last run in the new runlist. */ + for (; rl[1].length; rl++) + ; + /* Update the attribute record as well. */ + mrec = map_mft_record(mft_ni); + if (IS_ERR(mrec)) { + ntfs_error(vol->sb, "Failed to map mft record."); + ret = PTR_ERR(mrec); + goto undo_alloc; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, mrec); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + ret = -ENOMEM; + goto undo_alloc; + } + ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, + CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to find last attribute extent of " + "mft data attribute."); + if (ret == -ENOENT) + ret = -EIO; + goto undo_alloc; + } + a = ctx->attr; + ll = sle64_to_cpu(a->data.non_resident.lowest_vcn); + /* Search back for the previous last allocated cluster of mft bitmap. */ + for (rl2 = rl; rl2 > mft_ni->runlist.rl; rl2--) { + if (ll >= rl2->vcn) + break; + } + BUG_ON(ll < rl2->vcn); + BUG_ON(ll >= rl2->vcn + rl2->length); + /* Get the size for the new mapping pairs array for this extent. */ + mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll); + if (unlikely(mp_size <= 0)) { + ntfs_error(vol->sb, "Get size for mapping pairs failed for " + "mft data attribute extent."); + ret = mp_size; + if (!ret) + ret = -EIO; + goto undo_alloc; + } + /* Expand the attribute record if necessary. */ + old_alen = le32_to_cpu(a->length); + ret = ntfs_attr_record_resize(ctx->mrec, a, mp_size + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); + if (unlikely(ret)) { + if (ret != -ENOSPC) { + ntfs_error(vol->sb, "Failed to resize attribute " + "record for mft data attribute."); + goto undo_alloc; + } + // TODO: Deal with this by moving this extent to a new mft + // record or by starting a new extent in a new mft record or by + // moving other attributes out of this mft record. + // Note: Use the special reserved mft records and ensure that + // this extent is not required to find the mft record in + // question. + ntfs_error(vol->sb, "Not enough space in this mft record to " + "accomodate extended mft data attribute " + "extent. Cannot handle this yet."); + ret = -EOPNOTSUPP; + goto undo_alloc; + } + mp_rebuilt = TRUE; + /* Generate the mapping pairs array directly into the attr record. */ + ret = ntfs_mapping_pairs_build(vol, (u8*)a + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset), + mp_size, rl2, ll, NULL); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to build mapping pairs array of " + "mft data attribute."); + goto undo_alloc; + } + /* Update the highest_vcn. */ + a->data.non_resident.highest_vcn = cpu_to_sle64(rl[1].vcn - 1); + /* + * We now have extended the mft data allocated_size by nr clusters. + * Reflect this in the ntfs_inode structure and the attribute record. + * @rl is the last (non-terminator) runlist element of mft data + * attribute. + */ + if (a->data.non_resident.lowest_vcn) { + /* + * We are not in the first attribute extent, switch to it, but + * first ensure the changes will make it to disk later. + */ + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_reinit_search_ctx(ctx); + ret = ntfs_attr_lookup(mft_ni->type, mft_ni->name, + mft_ni->name_len, CASE_SENSITIVE, 0, NULL, 0, + ctx); + if (unlikely(ret)) { + ntfs_error(vol->sb, "Failed to find first attribute " + "extent of mft data attribute."); + goto restore_undo_alloc; + } + a = ctx->attr; + } + mft_ni->allocated_size += nr << vol->cluster_size_bits; + a->data.non_resident.allocated_size = + cpu_to_sle64(mft_ni->allocated_size); + /* 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(mft_ni); + up_write(&mft_ni->runlist.lock); + ntfs_debug("Done."); + return 0; +restore_undo_alloc: + ntfs_attr_reinit_search_ctx(ctx); + if (ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, + CASE_SENSITIVE, rl[1].vcn, NULL, 0, ctx)) { + ntfs_error(vol->sb, "Failed to find last attribute extent of " + "mft data attribute.%s", es); + mft_ni->allocated_size += nr << vol->cluster_size_bits; + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + up_write(&mft_ni->runlist.lock); + /* + * The only thing that is now wrong is ->allocated_size of the + * base attribute extent which chkdsk should be able to fix. + */ + NVolSetErrors(vol); + return ret; + } + a = ctx->attr; + a->data.non_resident.highest_vcn = cpu_to_sle64(old_last_vcn - 1); +undo_alloc: + if (ntfs_cluster_free(vol->mft_ino, old_last_vcn, -1) < 0) { + ntfs_error(vol->sb, "Failed to free clusters from mft data " + "attribute.%s", es); + NVolSetErrors(vol); + } + if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) { + ntfs_error(vol->sb, "Failed to truncate mft data attribute " + "runlist.%s", es); + NVolSetErrors(vol); + } + if (mp_rebuilt) { + if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + old_alen - le16_to_cpu( + a->data.non_resident.mapping_pairs_offset), + rl2, ll, NULL)) { + ntfs_error(vol->sb, "Failed to restore mapping pairs " + "array.%s", es); + NVolSetErrors(vol); + } + if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) { + ntfs_error(vol->sb, "Failed to restore attribute " + "record.%s", es); + NVolSetErrors(vol); + } + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + } + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (!IS_ERR(mrec)) + unmap_mft_record(mft_ni); + up_write(&mft_ni->runlist.lock); + return ret; +} + +/** + * ntfs_mft_record_layout - layout an mft record into a memory buffer + * @vol: volume to which the mft record will belong + * @mft_no: mft reference specifying the mft record number + * @m: destination buffer of size >= @vol->mft_record_size bytes + * + * Layout an empty, unused mft record with the mft record number @mft_no into + * the buffer @m. The volume @vol is needed because the mft record structure + * was modified in NTFS 3.1 so we need to know which volume version this mft + * record will be used on. + * + * Return 0 on success and -errno on error. + */ +static int ntfs_mft_record_layout(const ntfs_volume *vol, const s64 mft_no, + MFT_RECORD *m) +{ + ATTR_RECORD *a; + + ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); + if (mft_no >= (1ll << 32)) { + ntfs_error(vol->sb, "Mft record number 0x%llx exceeds " + "maximum of 2^32.", (long long)mft_no); + return -ERANGE; + } + /* Start by clearing the whole mft record to gives us a clean slate. */ + memset(m, 0, vol->mft_record_size); + /* Aligned to 2-byte boundary. */ + if (vol->major_ver < 3 || (vol->major_ver == 3 && !vol->minor_ver)) + m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD_OLD) + 1) & ~1); + else { + m->usa_ofs = cpu_to_le16((sizeof(MFT_RECORD) + 1) & ~1); + /* + * Set the NTFS 3.1+ specific fields while we know that the + * volume version is 3.1+. + */ + m->reserved = 0; + m->mft_record_number = cpu_to_le32((u32)mft_no); + } + m->magic = magic_FILE; + if (vol->mft_record_size >= NTFS_BLOCK_SIZE) + m->usa_count = cpu_to_le16(vol->mft_record_size / + NTFS_BLOCK_SIZE + 1); + else { + m->usa_count = cpu_to_le16(1); + ntfs_warning(vol->sb, "Sector size is bigger than mft record " + "size. Setting usa_count to 1. If chkdsk " + "reports this as corruption, please email " + "linux-ntfs-dev@lists.sourceforge.net stating " + "that you saw this message and that the " + "modified file system created was corrupt. " + "Thank you."); + } + /* Set the update sequence number to 1. */ + *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = cpu_to_le16(1); + m->lsn = 0; + m->sequence_number = cpu_to_le16(1); + m->link_count = 0; + /* + * Place the attributes straight after the update sequence array, + * aligned to 8-byte boundary. + */ + m->attrs_offset = cpu_to_le16((le16_to_cpu(m->usa_ofs) + + (le16_to_cpu(m->usa_count) << 1) + 7) & ~7); + m->flags = 0; + /* + * Using attrs_offset plus eight bytes (for the termination attribute). + * attrs_offset is already aligned to 8-byte boundary, so no need to + * align again. + */ + m->bytes_in_use = cpu_to_le32(le16_to_cpu(m->attrs_offset) + 8); + m->bytes_allocated = cpu_to_le32(vol->mft_record_size); + m->base_mft_record = 0; + m->next_attr_instance = 0; + /* Add the termination attribute. */ + a = (ATTR_RECORD*)((u8*)m + le16_to_cpu(m->attrs_offset)); + a->type = AT_END; + a->length = 0; + ntfs_debug("Done."); + return 0; +} + +/** + * ntfs_mft_record_format - format an mft record on an ntfs volume + * @vol: volume on which to format the mft record + * @mft_no: mft record number to format + * + * Format the mft record @mft_no in $MFT/$DATA, i.e. lay out an empty, unused + * mft record into the appropriate place of the mft data attribute. This is + * used when extending the mft data attribute. + * + * Return 0 on success and -errno on error. + */ +static int ntfs_mft_record_format(const ntfs_volume *vol, const s64 mft_no) +{ + struct inode *mft_vi = vol->mft_ino; + struct page *page; + MFT_RECORD *m; + pgoff_t index, end_index; + unsigned int ofs; + int err; + + ntfs_debug("Entering for mft record 0x%llx.", (long long)mft_no); + /* + * The index into the page cache and the offset within the page cache + * page of the wanted mft record. + */ + index = mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; + ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; + /* The maximum valid index into the page cache for $MFT's data. */ + end_index = mft_vi->i_size >> PAGE_CACHE_SHIFT; + if (unlikely(index >= end_index)) { + if (unlikely(index > end_index || ofs + vol->mft_record_size >= + (mft_vi->i_size & ~PAGE_CACHE_MASK))) { + ntfs_error(vol->sb, "Tried to format non-existing mft " + "record 0x%llx.", (long long)mft_no); + return -ENOENT; + } + } + /* Read, map, and pin the page containing the mft record. */ + page = ntfs_map_page(mft_vi->i_mapping, index); + if (unlikely(IS_ERR(page))) { + ntfs_error(vol->sb, "Failed to map page containing mft record " + "to format 0x%llx.", (long long)mft_no); + return PTR_ERR(page); + } + lock_page(page); + BUG_ON(!PageUptodate(page)); + ClearPageUptodate(page); + m = (MFT_RECORD*)((u8*)page_address(page) + ofs); + err = ntfs_mft_record_layout(vol, mft_no, m); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to layout mft record 0x%llx.", + (long long)mft_no); + SetPageUptodate(page); + unlock_page(page); + ntfs_unmap_page(page); + return err; + } + flush_dcache_page(page); + SetPageUptodate(page); + unlock_page(page); + /* + * Make sure the mft record is written out to disk. We could use + * ilookup5() to check if an inode is in icache and so on but this is + * unnecessary as ntfs_writepage() will write the dirty record anyway. + */ + mark_ntfs_record_dirty(page, ofs); + ntfs_unmap_page(page); + ntfs_debug("Done."); + return 0; +} + +/** + * ntfs_mft_record_alloc - allocate an mft record on an ntfs volume + * @vol: [IN] volume on which to allocate the mft record + * @mode: [IN] mode if want a file or directory, i.e. base inode or 0 + * @base_ni: [IN] open base inode if allocating an extent mft record or NULL + * @mrec: [OUT] on successful return this is the mapped mft record + * + * Allocate an mft record in $MFT/$DATA of an open ntfs volume @vol. + * + * If @base_ni is NULL make the mft record a base mft record, i.e. a file or + * direvctory inode, and allocate it at the default allocator position. In + * this case @mode is the file mode as given to us by the caller. We in + * particular use @mode to distinguish whether a file or a directory is being + * created (S_IFDIR(mode) and S_IFREG(mode), respectively). + * + * If @base_ni is not NULL make the allocated mft record an extent record, + * allocate it starting at the mft record after the base mft record and attach + * the allocated and opened ntfs inode to the base inode @base_ni. In this + * case @mode must be 0 as it is meaningless for extent inodes. + * + * You need to check the return value with IS_ERR(). If false, the function + * was successful and the return value is the now opened ntfs inode of the + * allocated mft record. *@mrec is then set to the allocated, mapped, pinned, + * and locked mft record. If IS_ERR() is true, the function failed and the + * error code is obtained from PTR_ERR(return value). *@mrec is undefined in + * this case. + * + * Allocation strategy: + * + * To find a free mft record, we scan the mft bitmap for a zero bit. To + * optimize this we start scanning at the place specified by @base_ni or if + * @base_ni is NULL we start where we last stopped and we perform wrap around + * when we reach the end. Note, we do not try to allocate mft records below + * number 24 because numbers 0 to 15 are the defined system files anyway and 16 + * to 24 are special in that they are used for storing extension mft records + * for the $DATA attribute of $MFT. This is required to avoid the possibility + * of creating a runlist with a circular dependency which once written to disk + * can never be read in again. Windows will only use records 16 to 24 for + * normal files if the volume is completely out of space. We never use them + * which means that when the volume is really out of space we cannot create any + * more files while Windows can still create up to 8 small files. We can start + * doing this at some later time, it does not matter much for now. + * + * When scanning the mft bitmap, we only search up to the last allocated mft + * record. If there are no free records left in the range 24 to number of + * allocated mft records, then we extend the $MFT/$DATA attribute in order to + * create free mft records. We extend the allocated size of $MFT/$DATA by 16 + * records at a time or one cluster, if cluster size is above 16kiB. If there + * is not sufficient space to do this, we try to extend by a single mft record + * or one cluster, if cluster size is above the mft record size. + * + * No matter how many mft records we allocate, we initialize only the first + * allocated mft record, incrementing mft data size and initialized size + * accordingly, open an ntfs_inode for it and return it to the caller, unless + * there are less than 24 mft records, in which case we allocate and initialize + * mft records until we reach record 24 which we consider as the first free mft + * record for use by normal files. + * + * If during any stage we overflow the initialized data in the mft bitmap, we + * extend the initialized size (and data size) by 8 bytes, allocating another + * cluster if required. The bitmap data size has to be at least equal to the + * number of mft records in the mft, but it can be bigger, in which case the + * superflous bits are padded with zeroes. + * + * Thus, when we return successfully (IS_ERR() is false), we will have: + * - initialized / extended the mft bitmap if necessary, + * - initialized / extended the mft data if necessary, + * - set the bit corresponding to the mft record being allocated in the + * mft bitmap, + * - opened an ntfs_inode for the allocated mft record, and we will have + * - returned the ntfs_inode as well as the allocated mapped, pinned, and + * locked mft record. + * + * On error, the volume will be left in a consistent state and no record will + * be allocated. If rolling back a partial operation fails, we may leave some + * inconsistent metadata in which case we set NVolErrors() so the volume is + * left dirty when unmounted. + * + * Note, this function cannot make use of most of the normal functions, like + * for example for attribute resizing, etc, because when the run list overflows + * the base mft record and an attribute list is used, it is very important that + * the extension mft records used to store the $DATA attribute of $MFT can be + * reached without having to read the information contained inside them, as + * this would make it impossible to find them in the first place after the + * volume is unmounted. $MFT/$BITMAP probably does not need to follow this + * rule because the bitmap is not essential for finding the mft records, but on + * the other hand, handling the bitmap in this special way would make life + * easier because otherwise there might be circular invocations of functions + * when reading the bitmap. + */ +ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, const int mode, + ntfs_inode *base_ni, MFT_RECORD **mrec) +{ + s64 ll, bit, old_data_initialized, old_data_size; + struct inode *vi; + struct page *page; + ntfs_inode *mft_ni, *mftbmp_ni, *ni; + ntfs_attr_search_ctx *ctx; + MFT_RECORD *m; + ATTR_RECORD *a; + pgoff_t index; + unsigned int ofs; + int err; + le16 seq_no, usn; + BOOL record_formatted = FALSE; + + if (base_ni) { + ntfs_debug("Entering (allocating an extent mft record for " + "base mft record 0x%llx).", + (long long)base_ni->mft_no); + /* @mode and @base_ni are mutually exclusive. */ + BUG_ON(mode); + } else + ntfs_debug("Entering (allocating a base mft record)."); + if (mode) { + /* @mode and @base_ni are mutually exclusive. */ + BUG_ON(base_ni); + /* We only support creation of normal files and directories. */ + if (!S_ISREG(mode) && !S_ISDIR(mode)) + return ERR_PTR(-EOPNOTSUPP); + } + BUG_ON(!mrec); + mft_ni = NTFS_I(vol->mft_ino); + mftbmp_ni = NTFS_I(vol->mftbmp_ino); + down_write(&vol->mftbmp_lock); + bit = ntfs_mft_bitmap_find_and_alloc_free_rec_nolock(vol, base_ni); + if (bit >= 0) { + ntfs_debug("Found and allocated free record (#1), bit 0x%llx.", + (long long)bit); + goto have_alloc_rec; + } + if (bit != -ENOSPC) { + up_write(&vol->mftbmp_lock); + return ERR_PTR(bit); + } + /* + * No free mft records left. If the mft bitmap already covers more + * than the currently used mft records, the next records are all free, + * so we can simply allocate the first unused mft record. + * Note: We also have to make sure that the mft bitmap at least covers + * the first 24 mft records as they are special and whilst they may not + * be in use, we do not allocate from them. + */ + ll = mft_ni->initialized_size >> vol->mft_record_size_bits; + if (mftbmp_ni->initialized_size << 3 > ll && + mftbmp_ni->initialized_size > 3) { + bit = ll; + if (bit < 24) + bit = 24; + if (unlikely(bit >= (1ll << 32))) + goto max_err_out; + ntfs_debug("Found free record (#2), bit 0x%llx.", + (long long)bit); + goto found_free_rec; + } + /* + * The mft bitmap needs to be expanded until it covers the first unused + * mft record that we can allocate. + * Note: The smallest mft record we allocate is mft record 24. + */ + bit = mftbmp_ni->initialized_size << 3; + if (unlikely(bit >= (1ll << 32))) + goto max_err_out; + ntfs_debug("Status of mftbmp before extension: allocated_size 0x%llx, " + "data_size 0x%llx, initialized_size 0x%llx.", + (long long)mftbmp_ni->allocated_size, + (long long)vol->mftbmp_ino->i_size, + (long long)mftbmp_ni->initialized_size); + if (mftbmp_ni->initialized_size + 8 > mftbmp_ni->allocated_size) { + /* Need to extend bitmap by one more cluster. */ + ntfs_debug("mftbmp: initialized_size + 8 > allocated_size."); + err = ntfs_mft_bitmap_extend_allocation_nolock(vol); + if (unlikely(err)) { + up_write(&vol->mftbmp_lock); + goto err_out; + } + ntfs_debug("Status of mftbmp after allocation extension: " + "allocated_size 0x%llx, data_size 0x%llx, " + "initialized_size 0x%llx.", + (long long)mftbmp_ni->allocated_size, + (long long)vol->mftbmp_ino->i_size, + (long long)mftbmp_ni->initialized_size); + } + /* + * We now have sufficient allocated space, extend the initialized_size + * as well as the data_size if necessary and fill the new space with + * zeroes. + */ + err = ntfs_mft_bitmap_extend_initialized_nolock(vol); + if (unlikely(err)) { + up_write(&vol->mftbmp_lock); + goto err_out; + } + ntfs_debug("Status of mftbmp after initialized extention: " + "allocated_size 0x%llx, data_size 0x%llx, " + "initialized_size 0x%llx.", + (long long)mftbmp_ni->allocated_size, + (long long)vol->mftbmp_ino->i_size, + (long long)mftbmp_ni->initialized_size); + ntfs_debug("Found free record (#3), bit 0x%llx.", (long long)bit); +found_free_rec: + /* @bit is the found free mft record, allocate it in the mft bitmap. */ + ntfs_debug("At found_free_rec."); + err = ntfs_bitmap_set_bit(vol->mftbmp_ino, bit); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to allocate bit in mft bitmap."); + up_write(&vol->mftbmp_lock); + goto err_out; + } + ntfs_debug("Set bit 0x%llx in mft bitmap.", (long long)bit); +have_alloc_rec: + /* + * The mft bitmap is now uptodate. Deal with mft data attribute now. + * Note, we keep hold of the mft bitmap lock for writing until all + * modifications to the mft data attribute are complete, too, as they + * will impact decisions for mft bitmap and mft record allocation done + * by a parallel allocation and if the lock is not maintained a + * parallel allocation could allocate the same mft record as this one. + */ + ll = (bit + 1) << vol->mft_record_size_bits; + if (ll <= mft_ni->initialized_size) { + ntfs_debug("Allocated mft record already initialized."); + goto mft_rec_already_initialized; + } + ntfs_debug("Initializing allocated mft record."); + /* + * The mft record is outside the initialized data. Extend the mft data + * attribute until it covers the allocated record. The loop is only + * actually traversed more than once when a freshly formatted volume is + * first written to so it optimizes away nicely in the common case. + */ + ntfs_debug("Status of mft data before extension: " + "allocated_size 0x%llx, data_size 0x%llx, " + "initialized_size 0x%llx.", + (long long)mft_ni->allocated_size, + (long long)vol->mft_ino->i_size, + (long long)mft_ni->initialized_size); + while (ll > mft_ni->allocated_size) { + err = ntfs_mft_data_extend_allocation_nolock(vol); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to extend mft data " + "allocation."); + goto undo_mftbmp_alloc_nolock; + } + ntfs_debug("Status of mft data after allocation extension: " + "allocated_size 0x%llx, data_size 0x%llx, " + "initialized_size 0x%llx.", + (long long)mft_ni->allocated_size, + (long long)vol->mft_ino->i_size, + (long long)mft_ni->initialized_size); + } + /* + * Extend mft data initialized size (and data size of course) to reach + * the allocated mft record, formatting the mft records allong the way. + * Note: We only modify the ntfs_inode structure as that is all that is + * needed by ntfs_mft_record_format(). We will update the attribute + * record itself in one fell swoop later on. + */ + old_data_initialized = mft_ni->initialized_size; + old_data_size = vol->mft_ino->i_size; + while (ll > mft_ni->initialized_size) { + s64 new_initialized_size, mft_no; + + new_initialized_size = mft_ni->initialized_size + + vol->mft_record_size; + mft_no = mft_ni->initialized_size >> vol->mft_record_size_bits; + if (new_initialized_size > vol->mft_ino->i_size) + vol->mft_ino->i_size = new_initialized_size; + ntfs_debug("Initializing mft record 0x%llx.", + (long long)mft_no); + err = ntfs_mft_record_format(vol, mft_no); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to format mft record."); + goto undo_data_init; + } + mft_ni->initialized_size = new_initialized_size; + } + record_formatted = TRUE; + /* Update the mft data attribute record to reflect the new sizes. */ + m = map_mft_record(mft_ni); + if (IS_ERR(m)) { + ntfs_error(vol->sb, "Failed to map mft record."); + err = PTR_ERR(m); + goto undo_data_init; + } + ctx = ntfs_attr_get_search_ctx(mft_ni, m); + if (unlikely(!ctx)) { + ntfs_error(vol->sb, "Failed to get search context."); + err = -ENOMEM; + unmap_mft_record(mft_ni); + goto undo_data_init; + } + err = ntfs_attr_lookup(mft_ni->type, mft_ni->name, mft_ni->name_len, + CASE_SENSITIVE, 0, NULL, 0, ctx); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to find first attribute extent of " + "mft data attribute."); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(mft_ni); + goto undo_data_init; + } + a = ctx->attr; + a->data.non_resident.initialized_size = + cpu_to_sle64(mft_ni->initialized_size); + a->data.non_resident.data_size = cpu_to_sle64(vol->mft_ino->i_size); + /* 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(mft_ni); + ntfs_debug("Status of mft data after mft record initialization: " + "allocated_size 0x%llx, data_size 0x%llx, " + "initialized_size 0x%llx.", + (long long)mft_ni->allocated_size, + (long long)vol->mft_ino->i_size, + (long long)mft_ni->initialized_size); + BUG_ON(vol->mft_ino->i_size > mft_ni->allocated_size); + BUG_ON(mft_ni->initialized_size > vol->mft_ino->i_size); +mft_rec_already_initialized: + /* + * We can finally drop the mft bitmap lock as the mft data attribute + * has been fully updated. The only disparity left is that the + * allocated mft record still needs to be marked as in use to match the + * set bit in the mft bitmap but this is actually not a problem since + * this mft record is not referenced from anywhere yet and the fact + * that it is allocated in the mft bitmap means that no-one will try to + * allocate it either. + */ + up_write(&vol->mftbmp_lock); + /* + * We now have allocated and initialized the mft record. Calculate the + * index of and the offset within the page cache page the record is in. + */ + index = bit << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; + ofs = (bit << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; + /* Read, map, and pin the page containing the mft record. */ + page = ntfs_map_page(vol->mft_ino->i_mapping, index); + if (unlikely(IS_ERR(page))) { + ntfs_error(vol->sb, "Failed to map page containing allocated " + "mft record 0x%llx.", (long long)bit); + err = PTR_ERR(page); + goto undo_mftbmp_alloc; + } + lock_page(page); + BUG_ON(!PageUptodate(page)); + ClearPageUptodate(page); + m = (MFT_RECORD*)((u8*)page_address(page) + ofs); + /* If we just formatted the mft record no need to do it again. */ + if (!record_formatted) { + /* Sanity check that the mft record is really not in use. */ + if (ntfs_is_file_record(m->magic) && + (m->flags & MFT_RECORD_IN_USE)) { + ntfs_error(vol->sb, "Mft record 0x%llx was marked " + "free in mft bitmap but is marked " + "used itself. Corrupt filesystem. " + "Unmount and run chkdsk.", + (long long)bit); + err = -EIO; + SetPageUptodate(page); + unlock_page(page); + ntfs_unmap_page(page); + NVolSetErrors(vol); + goto undo_mftbmp_alloc; + } + /* + * We need to (re-)format the mft record, preserving the + * sequence number if it is not zero as well as the update + * sequence number if it is not zero or -1 (0xffff). This + * means we do not need to care whether or not something went + * wrong with the previous mft record. + */ + seq_no = m->sequence_number; + usn = *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)); + err = ntfs_mft_record_layout(vol, bit, m); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to layout allocated mft " + "record 0x%llx.", (long long)bit); + SetPageUptodate(page); + unlock_page(page); + ntfs_unmap_page(page); + goto undo_mftbmp_alloc; + } + if (seq_no) + m->sequence_number = seq_no; + if (usn && le16_to_cpu(usn) != 0xffff) + *(le16*)((u8*)m + le16_to_cpu(m->usa_ofs)) = usn; + } + /* Set the mft record itself in use. */ + m->flags |= MFT_RECORD_IN_USE; + if (S_ISDIR(mode)) + m->flags |= MFT_RECORD_IS_DIRECTORY; + flush_dcache_page(page); + SetPageUptodate(page); + if (base_ni) { + /* + * Setup the base mft record in the extent mft record. This + * completes initialization of the allocated extent mft record + * and we can simply use it with map_extent_mft_record(). + */ + m->base_mft_record = MK_LE_MREF(base_ni->mft_no, + base_ni->seq_no); + /* + * Allocate an extent inode structure for the new mft record, + * attach it to the base inode @base_ni and map, pin, and lock + * its, i.e. the allocated, mft record. + */ + m = map_extent_mft_record(base_ni, bit, &ni); + if (IS_ERR(m)) { + ntfs_error(vol->sb, "Failed to map allocated extent " + "mft record 0x%llx.", (long long)bit); + err = PTR_ERR(m); + /* Set the mft record itself not in use. */ + m->flags &= cpu_to_le16( + ~le16_to_cpu(MFT_RECORD_IN_USE)); + flush_dcache_page(page); + /* Make sure the mft record is written out to disk. */ + mark_ntfs_record_dirty(page, ofs); + unlock_page(page); + ntfs_unmap_page(page); + goto undo_mftbmp_alloc; + } + /* + * Make sure the allocated mft record is written out to disk. + * No need to set the inode dirty because the caller is going + * to do that anyway after finishing with the new extent mft + * record (e.g. at a minimum a new attribute will be added to + * the mft record. + */ + mark_ntfs_record_dirty(page, ofs); + unlock_page(page); + /* + * Need to unmap the page since map_extent_mft_record() mapped + * it as well so we have it mapped twice at the moment. + */ + ntfs_unmap_page(page); + } else { + /* + * Allocate a new VFS inode and set it up. NOTE: @vi->i_nlink + * is set to 1 but the mft record->link_count is 0. The caller + * needs to bear this in mind. + */ + vi = new_inode(vol->sb); + if (unlikely(!vi)) { + err = -ENOMEM; + /* Set the mft record itself not in use. */ + m->flags &= cpu_to_le16( + ~le16_to_cpu(MFT_RECORD_IN_USE)); + flush_dcache_page(page); + /* Make sure the mft record is written out to disk. */ + mark_ntfs_record_dirty(page, ofs); + unlock_page(page); + ntfs_unmap_page(page); + goto undo_mftbmp_alloc; + } + vi->i_ino = bit; + /* + * This is the optimal IO size (for stat), not the fs block + * size. + */ + vi->i_blksize = PAGE_CACHE_SIZE; + /* + * This is for checking whether an inode has changed w.r.t. a + * file so that the file can be updated if necessary (compare + * with f_version). + */ + vi->i_version = 1; + + /* The owner and group come from the ntfs volume. */ + vi->i_uid = vol->uid; + vi->i_gid = vol->gid; + + /* Initialize the ntfs specific part of @vi. */ + ntfs_init_big_inode(vi); + ni = NTFS_I(vi); + /* + * Set the appropriate mode, attribute type, and name. For + * directories, also setup the index values to the defaults. + */ + if (S_ISDIR(mode)) { + vi->i_mode = S_IFDIR | S_IRWXUGO; + vi->i_mode &= ~vol->dmask; + + NInoSetMstProtected(ni); + ni->type = AT_INDEX_ALLOCATION; + ni->name = I30; + ni->name_len = 4; + + ni->itype.index.block_size = 4096; + ni->itype.index.block_size_bits = generic_ffs(4096) - 1; + ni->itype.index.collation_rule = COLLATION_FILE_NAME; + if (vol->cluster_size <= ni->itype.index.block_size) { + ni->itype.index.vcn_size = vol->cluster_size; + ni->itype.index.vcn_size_bits = + vol->cluster_size_bits; + } else { + ni->itype.index.vcn_size = vol->sector_size; + ni->itype.index.vcn_size_bits = + vol->sector_size_bits; + } + } else { + vi->i_mode = S_IFREG | S_IRWXUGO; + vi->i_mode &= ~vol->fmask; + + ni->type = AT_DATA; + ni->name = NULL; + ni->name_len = 0; + } + if (IS_RDONLY(vi)) + vi->i_mode &= ~S_IWUGO; + + /* Set the inode times to the current time. */ + vi->i_atime = vi->i_mtime = vi->i_ctime = + current_fs_time(vi->i_sb); + /* + * Set the file size to 0, the ntfs inode sizes are set to 0 by + * the call to ntfs_init_big_inode() below. + */ + vi->i_size = 0; + vi->i_blocks = 0; + + /* Set the sequence number. */ + vi->i_generation = ni->seq_no = le16_to_cpu(m->sequence_number); + /* + * Manually map, pin, and lock the mft record as we already + * have its page mapped and it is very easy to do. + */ + atomic_inc(&ni->count); + down(&ni->mrec_lock); + ni->page = page; + ni->page_ofs = ofs; + /* + * Make sure the allocated mft record is written out to disk. + * NOTE: We do not set the ntfs inode dirty because this would + * fail in ntfs_write_inode() because the inode does not have a + * standard information attribute yet. Also, there is no need + * to set the inode dirty because the caller is going to do + * that anyway after finishing with the new mft record (e.g. at + * a minimum some new attributes will be added to the mft + * record. + */ + mark_ntfs_record_dirty(page, ofs); + unlock_page(page); + + /* Add the inode to the inode hash for the superblock. */ + insert_inode_hash(vi); + + /* Update the default mft allocation position. */ + vol->mft_data_pos = bit + 1; + } + /* + * Return the opened, allocated inode of the allocated mft record as + * well as the mapped, pinned, and locked mft record. + */ + ntfs_debug("Returning opened, allocated %sinode 0x%llx.", + base_ni ? "extent " : "", (long long)bit); + *mrec = m; + return ni; +undo_data_init: + mft_ni->initialized_size = old_data_initialized; + vol->mft_ino->i_size = old_data_size; + goto undo_mftbmp_alloc_nolock; +undo_mftbmp_alloc: + down_write(&vol->mftbmp_lock); +undo_mftbmp_alloc_nolock: + if (ntfs_bitmap_clear_bit(vol->mftbmp_ino, bit)) { + ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); + NVolSetErrors(vol); + } + up_write(&vol->mftbmp_lock); +err_out: + return ERR_PTR(err); +max_err_out: + ntfs_warning(vol->sb, "Cannot allocate mft record because the maximum " + "number of inodes (2^32) has already been reached."); + up_write(&vol->mftbmp_lock); + return ERR_PTR(-ENOSPC); +} + +/** + * ntfs_extent_mft_record_free - free an extent mft record on an ntfs volume + * @ni: ntfs inode of the mapped extent mft record to free + * @m: mapped extent mft record of the ntfs inode @ni + * + * Free the mapped extent mft record @m of the extent ntfs inode @ni. + * + * Note that this function unmaps the mft record and closes and destroys @ni + * internally and hence you cannot use either @ni nor @m any more after this + * function returns success. + * + * On success return 0 and on error return -errno. @ni and @m are still valid + * in this case and have not been freed. + * + * For some errors an error message is displayed and the success code 0 is + * returned and the volume is then left dirty on umount. This makes sense in + * case we could not rollback the changes that were already done since the + * caller no longer wants to reference this mft record so it does not matter to + * the caller if something is wrong with it as long as it is properly detached + * from the base inode. + */ +int ntfs_extent_mft_record_free(ntfs_inode *ni, MFT_RECORD *m) +{ + unsigned long mft_no = ni->mft_no; + ntfs_volume *vol = ni->vol; + ntfs_inode *base_ni; + ntfs_inode **extent_nis; + int i, err; + le16 old_seq_no; + u16 seq_no; + + BUG_ON(NInoAttr(ni)); + BUG_ON(ni->nr_extents != -1); + + down(&ni->extent_lock); + base_ni = ni->ext.base_ntfs_ino; + up(&ni->extent_lock); + + BUG_ON(base_ni->nr_extents <= 0); + + ntfs_debug("Entering for extent inode 0x%lx, base inode 0x%lx.\n", + mft_no, base_ni->mft_no); + + down(&base_ni->extent_lock); + + /* Make sure we are holding the only reference to the extent inode. */ + if (atomic_read(&ni->count) > 2) { + ntfs_error(vol->sb, "Tried to free busy extent inode 0x%lx, " + "not freeing.", base_ni->mft_no); + up(&base_ni->extent_lock); + return -EBUSY; + } + + /* Dissociate the ntfs inode from the base inode. */ + extent_nis = base_ni->ext.extent_ntfs_inos; + err = -ENOENT; + for (i = 0; i < base_ni->nr_extents; i++) { + if (ni != extent_nis[i]) + continue; + extent_nis += i; + base_ni->nr_extents--; + memmove(extent_nis, extent_nis + 1, (base_ni->nr_extents - i) * + sizeof(ntfs_inode*)); + err = 0; + break; + } + + up(&base_ni->extent_lock); + + if (unlikely(err)) { + ntfs_error(vol->sb, "Extent inode 0x%lx is not attached to " + "its base inode 0x%lx.", mft_no, + base_ni->mft_no); + BUG(); + } + + /* + * The extent inode is no longer attached to the base inode so no one + * can get a reference to it any more. + */ + + /* Mark the mft record as not in use. */ + m->flags &= const_cpu_to_le16(~const_le16_to_cpu(MFT_RECORD_IN_USE)); + + /* Increment the sequence number, skipping zero, if it is not zero. */ + old_seq_no = m->sequence_number; + seq_no = le16_to_cpu(old_seq_no); + if (seq_no == 0xffff) + seq_no = 1; + else if (seq_no) + seq_no++; + m->sequence_number = cpu_to_le16(seq_no); + + /* + * Set the ntfs inode dirty and write it out. We do not need to worry + * about the base inode here since whatever caused the extent mft + * record to be freed is guaranteed to do it already. + */ + NInoSetDirty(ni); + err = write_mft_record(ni, m, 0); + if (unlikely(err)) { + ntfs_error(vol->sb, "Failed to write mft record 0x%lx, not " + "freeing.", mft_no); + goto rollback; + } +rollback_error: + /* Unmap and throw away the now freed extent inode. */ + unmap_extent_mft_record(ni); + ntfs_clear_extent_inode(ni); + + /* Clear the bit in the $MFT/$BITMAP corresponding to this record. */ + down_write(&vol->mftbmp_lock); + err = ntfs_bitmap_clear_bit(vol->mftbmp_ino, mft_no); + up_write(&vol->mftbmp_lock); + if (unlikely(err)) { + /* + * The extent inode is gone but we failed to deallocate it in + * the mft bitmap. Just emit a warning and leave the volume + * dirty on umount. + */ + ntfs_error(vol->sb, "Failed to clear bit in mft bitmap.%s", es); + NVolSetErrors(vol); + } + return 0; +rollback: + /* Rollback what we did... */ + down(&base_ni->extent_lock); + extent_nis = base_ni->ext.extent_ntfs_inos; + if (!(base_ni->nr_extents & 3)) { + int new_size = (base_ni->nr_extents + 4) * sizeof(ntfs_inode*); + + extent_nis = (ntfs_inode**)kmalloc(new_size, GFP_NOFS); + if (unlikely(!extent_nis)) { + ntfs_error(vol->sb, "Failed to allocate internal " + "buffer during rollback.%s", es); + up(&base_ni->extent_lock); + NVolSetErrors(vol); + goto rollback_error; + } + if (base_ni->nr_extents) { + BUG_ON(!base_ni->ext.extent_ntfs_inos); + memcpy(extent_nis, base_ni->ext.extent_ntfs_inos, + new_size - 4 * sizeof(ntfs_inode*)); + kfree(base_ni->ext.extent_ntfs_inos); + } + base_ni->ext.extent_ntfs_inos = extent_nis; + } + m->flags |= MFT_RECORD_IN_USE; + m->sequence_number = old_seq_no; + extent_nis[base_ni->nr_extents++] = ni; + up(&base_ni->extent_lock); + mark_mft_record_dirty(ni); + return err; +} +#endif /* NTFS_RW */ |