/** * mft.c - NTFS kernel mft record operations. Part of the Linux-NTFS project. * * Copyright (c) 2001-2006 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) { loff_t i_size; ntfs_volume *vol = ni->vol; struct inode *mft_vi = vol->mft_ino; struct page *page; unsigned long index, end_index; unsigned ofs; 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 = (u64)ni->mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT; ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK; i_size = i_size_read(mft_vi); /* The maximum valid index into the page cache for $MFT's data. */ end_index = 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 || (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); NVolSetErrors(vol); } 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 mutex. We might now be sleeping, while waiting * for the mutex 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 mutex. 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. */ mutex_lock(&ni->mrec_lock); m = map_mft_record_page(ni); if (likely(!IS_ERR(m))) return m; mutex_unlock(&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); mutex_unlock(&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. */ mutex_lock(&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)) { mutex_unlock(&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 filesystem. " "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)) { mutex_unlock(&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)) { mutex_unlock(&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 filesystem. 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 = 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; mutex_unlock(&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); mutex_unlock(&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. */ mutex_lock(&ni->extent_lock); if (likely(ni->nr_extents >= 0)) base_ni = ni; else base_ni = ni->ext.base_ntfs_ino; mutex_unlock(&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->sb->s_blocksize_bits; 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); } 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; bh->b_bdev = vol->sb->s_bdev; /* 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. * * 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 int blocksize = vol->sb->s_blocksize; unsigned char blocksize_bits = vol->sb->s_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; 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; bh->b_bdev = vol->sb->s_bdev; /* 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; /* * Optimize inode 0, i.e. $MFT itself, since we have it in memory and * we get here for it rather often. */ if (!mft_no) { /* Balance the below iput(). */ vi = igrab(mft_vi); BUG_ON(vi != mft_vi); } else { /* * Have to use ilookup5_nowait() since ilookup5() waits for the * inode lock which causes ntfs to deadlock when a concurrent * inode write via the inode dirty code paths and the page * dirty code path of the inode dirty code path when writing * $MFT occurs. */ vi = ilookup5_nowait(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(!mutex_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); if (!na.mft_no) { /* Balance the below iput(). */ vi = igrab(mft_vi); BUG_ON(vi != mft_vi); } else vi = ilookup5_nowait(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); mutex_lock(&ni->extent_lock); if (ni->nr_extents <= 0) { /* * The base inode has no attached extent inodes, write this * extent mft record. */ mutex_unlock(&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) { mutex_unlock(&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); mutex_unlock(&ni->extent_lock); /* * Found the extent inode coresponding to this extent mft record. * Try to take the mft record lock. */ if (unlikely(!mutex_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; unsigned long flags; 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. */ read_lock_irqsave(&NTFS_I(vol->mft_ino)->size_lock, flags); pass_end = NTFS_I(vol->mft_ino)->allocated_size >> vol->mft_record_size_bits; read_unlock_irqrestore(&NTFS_I(vol->mft_ino)->size_lock, flags); read_lock_irqsave(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); ll = NTFS_I(vol->mftbmp_ino)->initialized_size << 3; read_unlock_irqrestore(&NTFS_I(vol->mftbmp_ino)->size_lock, flags); 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 (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; unsigned long flags; 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. */ down_write(&mftbmp_ni->runlist.lock); read_lock_irqsave(&mftbmp_ni->size_lock, flags); ll = mftbmp_ni->allocated_size; read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); rl = ntfs_attr_find_vcn_nolock(mftbmp_ni, (ll - 1) >> vol->cluster_size_bits, NULL); if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { up_write(&mftbmp_ni->runlist.lock); ntfs_error(vol->sb, "Failed to determine last allocated " "cluster of mft bitmap attribute."); if (!IS_ERR(rl)) 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, true); 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, -1); 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. // Note: It will need to be a special mft record and if none of // those are available it gets rather complicated... 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, -1, 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; } write_lock_irqsave(&mftbmp_ni->size_lock, flags); mftbmp_ni->allocated_size += vol->cluster_size; a->data.non_resident.allocated_size = cpu_to_sle64(mftbmp_ni->allocated_size); write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); /* Ensure the changes make it to disk. */ flush_dcache_mft_record_page(ctx->ntfs_ino); mark_mft_record_dirty(ctx->ntfs_ino); ntfs_attr_put_search_ctx(ctx); unmap_mft_record(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); write_lock_irqsave(&mftbmp_ni->size_lock, flags); mftbmp_ni->allocated_size += vol->cluster_size; write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 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, -1, 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; unsigned long flags; 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; write_lock_irqsave(&mftbmp_ni->size_lock, flags); old_data_size = i_size_read(mftbmp_vi); 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 > old_data_size) { i_size_write(mftbmp_vi, mftbmp_ni->initialized_size); a->data.non_resident.data_size = cpu_to_sle64(mftbmp_ni->initialized_size); } write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); /* Ensure the changes make it to disk. */ flush_dcache_mft_record_page(ctx->ntfs_ino); mark_mft_record_dirty(ctx->ntfs_ino); ntfs_attr_put_search_ctx(ctx); unmap_mft_record(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; write_lock_irqsave(&mftbmp_ni->size_lock, flags); mftbmp_ni->initialized_size = old_initialized_size; a->data.non_resident.initialized_size = cpu_to_sle64(old_initialized_size); if (i_size_read(mftbmp_vi) != old_data_size) { i_size_write(mftbmp_vi, old_data_size); a->data.non_resident.data_size = cpu_to_sle64(old_data_size); } write_unlock_irqrestore(&mftbmp_ni->size_lock, flags); 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); #ifdef DEBUG read_lock_irqsave(&mftbmp_ni->size_lock, flags); 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)i_size_read(mftbmp_vi), (long long)mftbmp_ni->initialized_size); read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); #endif /* DEBUG */ 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; unsigned long flags; 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. */ down_write(&mft_ni->runlist.lock); read_lock_irqsave(&mft_ni->size_lock, flags); ll = mft_ni->allocated_size; read_unlock_irqrestore(&mft_ni->size_lock, flags); rl = ntfs_attr_find_vcn_nolock(mft_ni, (ll - 1) >> vol->cluster_size_bits, NULL); if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) { up_write(&mft_ni->runlist.lock); ntfs_error(vol->sb, "Failed to determine last allocated " "cluster of mft data attribute."); if (!IS_ERR(rl)) 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. */ read_lock_irqsave(&mft_ni->size_lock, flags); ll = mft_ni->allocated_size; read_unlock_irqrestore(&mft_ni->size_lock, flags); if (unlikely((ll + (nr << vol->cluster_size_bits)) >> vol->mft_record_size_bits >= (1ll << 32))) { nr = min_nr; if (unlikely((ll + (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, true); 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.", (long long)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, -1); 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. If no free special records left we would need to // move an existing record away, insert ours in its place, and // then place the moved record into the newly allocated space // and we would then need to update all references to this mft // record appropriately. This is rather complicated... 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, -1, 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; } write_lock_irqsave(&mft_ni->size_lock, flags); mft_ni->allocated_size += nr << vol->cluster_size_bits; a->data.non_resident.allocated_size = cpu_to_sle64(mft_ni->allocated_size); write_unlock_irqrestore(&mft_ni->size_lock, flags); /* Ensure the changes make it to disk. */ flush_dcache_mft_record_page(ctx->ntfs_ino); mark_mft_record_dirty(ctx->ntfs_ino); ntfs_attr_put_search_ctx(ctx); unmap_mft_record(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); write_lock_irqsave(&mft_ni->size_lock, flags); mft_ni->allocated_size += nr << vol->cluster_size_bits; write_unlock_irqrestore(&mft_ni->size_lock, flags); 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; } ctx->attr->data.non_resident.highest_vcn = cpu_to_sle64(old_last_vcn - 1); undo_alloc: if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) { ntfs_error(vol->sb, "Failed to free clusters from mft data " "attribute.%s", es); NVolSetErrors(vol); } a = ctx->attr; 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 && !IS_ERR(ctx->mrec)) { 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, -1, 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); } else if (IS_ERR(ctx->mrec)) { ntfs_error(vol->sb, "Failed to restore attribute search " "context.%s", es); NVolSetErrors(vol); } 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 filesystem 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) { loff_t i_size; 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. */ i_size = i_size_read(mft_vi); end_index = i_size >> PAGE_CACHE_SHIFT; if (unlikely(index >= end_index)) { if (unlikely(index > end_index || ofs + vol->mft_record_size >= (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 (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; unsigned long flags; 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. */ read_lock_irqsave(&mft_ni->size_lock, flags); ll = mft_ni->initialized_size >> vol->mft_record_size_bits; read_unlock_irqrestore(&mft_ni->size_lock, flags); read_lock_irqsave(&mftbmp_ni->size_lock, flags); old_data_initialized = mftbmp_ni->initialized_size; read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); if (old_data_initialized << 3 > ll && old_data_initialized > 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 = old_data_initialized << 3; if (unlikely(bit >= (1ll << 32))) goto max_err_out; read_lock_irqsave(&mftbmp_ni->size_lock, flags); old_data_size = mftbmp_ni->allocated_size; ntfs_debug("Status of mftbmp before extension: allocated_size 0x%llx, " "data_size 0x%llx, initialized_size 0x%llx.", (long long)old_data_size, (long long)i_size_read(vol->mftbmp_ino), (long long)old_data_initialized); read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); if (old_data_initialized + 8 > old_data_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; } #ifdef DEBUG read_lock_irqsave(&mftbmp_ni->size_lock, flags); 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)i_size_read(vol->mftbmp_ino), (long long)mftbmp_ni->initialized_size); read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); #endif /* DEBUG */ } /* * 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; } #ifdef DEBUG read_lock_irqsave(&mftbmp_ni->size_lock, flags); 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)i_size_read(vol->mftbmp_ino), (long long)mftbmp_ni->initialized_size); read_unlock_irqrestore(&mftbmp_ni->size_lock, flags); #endif /* DEBUG */ 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; read_lock_irqsave(&mft_ni->size_lock, flags); old_data_initialized = mft_ni->initialized_size; read_unlock_irqrestore(&mft_ni->size_lock, flags); if (ll <= old_data_initialized) { 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. */ read_lock_irqsave(&mft_ni->size_lock, flags); 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)i_size_read(vol->mft_ino), (long long)mft_ni->initialized_size); while (ll > mft_ni->allocated_size) { read_unlock_irqrestore(&mft_ni->size_lock, flags); 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; } read_lock_irqsave(&mft_ni->size_lock, flags); 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)i_size_read(vol->mft_ino), (long long)mft_ni->initialized_size); } read_unlock_irqrestore(&mft_ni->size_lock, flags); /* * 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. */ write_lock_irqsave(&mft_ni->size_lock, flags); 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 > i_size_read(vol->mft_ino)) i_size_write(vol->mft_ino, new_initialized_size); write_unlock_irqrestore(&mft_ni->size_lock, flags); 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; } write_lock_irqsave(&mft_ni->size_lock, flags); mft_ni->initialized_size = new_initialized_size; } write_unlock_irqrestore(&mft_ni->size_lock, flags); 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; read_lock_irqsave(&mft_ni->size_lock, flags); a->data.non_resident.initialized_size = cpu_to_sle64(mft_ni->initialized_size); a->data.non_resident.data_size = cpu_to_sle64(i_size_read(vol->mft_ino)); read_unlock_irqrestore(&mft_ni->size_lock, flags); /* Ensure the changes make it to disk. */ flush_dcache_mft_record_page(ctx->ntfs_ino); mark_mft_record_dirty(ctx->ntfs_ino); ntfs_attr_put_search_ctx(ctx); unmap_mft_record(mft_ni); read_lock_irqsave(&mft_ni->size_lock, flags); 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)i_size_read(vol->mft_ino), (long long)mft_ni->initialized_size); BUG_ON(i_size_read(vol->mft_ino) > mft_ni->allocated_size); BUG_ON(mft_ni->initialized_size > i_size_read(vol->mft_ino)); read_unlock_irqrestore(&mft_ni->size_lock, flags); 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 (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 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 = ntfs_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); mutex_lock(&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: write_lock_irqsave(&mft_ni->size_lock, flags); mft_ni->initialized_size = old_data_initialized; i_size_write(vol->mft_ino, old_data_size); write_unlock_irqrestore(&mft_ni->size_lock, flags); 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); mutex_lock(&ni->extent_lock); base_ni = ni->ext.base_ntfs_ino; mutex_unlock(&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); mutex_lock(&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); mutex_unlock(&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; } mutex_unlock(&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... */ mutex_lock(&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 = kmalloc(new_size, GFP_NOFS); if (unlikely(!extent_nis)) { ntfs_error(vol->sb, "Failed to allocate internal " "buffer during rollback.%s", es); mutex_unlock(&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; mutex_unlock(&base_ni->extent_lock); mark_mft_record_dirty(ni); return err; } #endif /* NTFS_RW */