From dd072330d1a60be11a5c284fa1e645350750a4fc Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov Date: Tue, 4 Oct 2005 15:39:02 +0100 Subject: [PATCH] NTFS: Implement fs/ntfs/inode.[hc]::ntfs_truncate(). It only supports uncompressed and unencrypted files. Signed-off-by: Anton Altaparmakov --- fs/ntfs/ChangeLog | 20 +- fs/ntfs/inode.c | 491 ++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 468 insertions(+), 43 deletions(-) diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog index 6c5bdfbb7bbf..70ad4be7a7fe 100644 --- a/fs/ntfs/ChangeLog +++ b/fs/ntfs/ChangeLog @@ -3,16 +3,14 @@ ToDo/Notes: - In between ntfs_prepare/commit_write, need exclusion between simultaneous file extensions. This is given to us by holding i_sem on the inode. The only places in the kernel when a file is resized - are prepare/commit write and truncate for both of which i_sem is - held. Just have to be careful in readpage/writepage and all other - helpers not running under i_sem that we play nice... - Also need to be careful with initialized_size extention in - ntfs_prepare_write. Basically, just be _very_ careful in this code... - UPDATE: The only things that need to be checked are read/writepage - which do not hold i_sem. Note writepage cannot change i_size but it - needs to cope with a concurrent i_size change, just like readpage. - Also both need to cope with concurrent changes to the other sizes, - i.e. initialized/allocated/compressed size, as well. + are prepare/commit write and ntfs_truncate() for both of which i_sem + is held. Just have to be careful in read-/writepage and other helpers + not running under i_sem that we play nice... Also need to be careful + with initialized_size extention in ntfs_prepare_write and writepage. + UPDATE: The only things that need to be checked are + prepare/commit_write as well as the compressed write and the other + attribute resize/write cases like index attributes, etc. For now + none of these are implemented so are safe. - Implement mft.c::sync_mft_mirror_umount(). We currently will just leave the volume dirty on umount if the final iput(vol->mft_ino) causes a write of any mirrored mft records due to the mft mirror @@ -50,6 +48,8 @@ ToDo/Notes: - Add fs/ntfs/attrib.[hc]::ntfs_attr_extend_allocation(), a function to extend the allocation of an attributes. Optionally, the data size, but not the initialized size can be extended, too. + - Implement fs/ntfs/inode.[hc]::ntfs_truncate(). It only supports + uncompressed and unencrypted files. 2.1.24 - Lots of bug fixes and support more clean journal states. diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c index 7ec045131808..a1682342baa6 100644 --- a/fs/ntfs/inode.c +++ b/fs/ntfs/inode.c @@ -30,6 +30,7 @@ #include "debug.h" #include "inode.h" #include "attrib.h" +#include "lcnalloc.h" #include "malloc.h" #include "mft.h" #include "time.h" @@ -2291,11 +2292,16 @@ int ntfs_show_options(struct seq_file *sf, struct vfsmount *mnt) #ifdef NTFS_RW +static const char *es = " Leaving inconsistent metadata. Unmount and run " + "chkdsk."; + /** * ntfs_truncate - called when the i_size of an ntfs inode is changed * @vi: inode for which the i_size was changed * - * We do not support i_size changes yet. + * We only support i_size changes for normal files at present, i.e. not + * compressed and not encrypted. This is enforced in ntfs_setattr(), see + * below. * * The kernel guarantees that @vi is a regular file (S_ISREG() is true) and * that the change is allowed. @@ -2306,80 +2312,499 @@ int ntfs_show_options(struct seq_file *sf, struct vfsmount *mnt) * Returns 0 on success or -errno on error. * * Called with ->i_sem held. In all but one case ->i_alloc_sem is held for - * writing. The only case where ->i_alloc_sem is not held is + * writing. The only case in the kernel where ->i_alloc_sem is not held is * mm/filemap.c::generic_file_buffered_write() where vmtruncate() is called - * with the current i_size as the offset which means that it is a noop as far - * as ntfs_truncate() is concerned. + * with the current i_size as the offset. The analogous place in NTFS is in + * fs/ntfs/file.c::ntfs_file_buffered_write() where we call vmtruncate() again + * without holding ->i_alloc_sem. */ int ntfs_truncate(struct inode *vi) { - ntfs_inode *ni = NTFS_I(vi); + s64 new_size, old_size, nr_freed, new_alloc_size, old_alloc_size; + VCN highest_vcn; + unsigned long flags; + ntfs_inode *base_ni, *ni = NTFS_I(vi); ntfs_volume *vol = ni->vol; ntfs_attr_search_ctx *ctx; MFT_RECORD *m; ATTR_RECORD *a; const char *te = " Leaving file length out of sync with i_size."; - int err; + int err, mp_size, size_change, alloc_change; + u32 attr_len; ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); BUG_ON(NInoAttr(ni)); + BUG_ON(S_ISDIR(vi->i_mode)); + BUG_ON(NInoMstProtected(ni)); BUG_ON(ni->nr_extents < 0); - m = map_mft_record(ni); +retry_truncate: + /* + * Lock the runlist for writing and map the mft record to ensure it is + * safe to mess with the attribute runlist and sizes. + */ + down_write(&ni->runlist.lock); + if (!NInoAttr(ni)) + base_ni = ni; + else + base_ni = ni->ext.base_ntfs_ino; + m = map_mft_record(base_ni); if (IS_ERR(m)) { err = PTR_ERR(m); ntfs_error(vi->i_sb, "Failed to map mft record for inode 0x%lx " "(error code %d).%s", vi->i_ino, err, te); ctx = NULL; m = NULL; - goto err_out; + goto old_bad_out; } - ctx = ntfs_attr_get_search_ctx(ni, m); + ctx = ntfs_attr_get_search_ctx(base_ni, m); if (unlikely(!ctx)) { ntfs_error(vi->i_sb, "Failed to allocate a search context for " "inode 0x%lx (not enough memory).%s", vi->i_ino, te); err = -ENOMEM; - goto err_out; + goto old_bad_out; } err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE, 0, NULL, 0, ctx); if (unlikely(err)) { - if (err == -ENOENT) + if (err == -ENOENT) { ntfs_error(vi->i_sb, "Open attribute is missing from " "mft record. Inode 0x%lx is corrupt. " - "Run chkdsk.", vi->i_ino); - else + "Run chkdsk.%s", vi->i_ino, te); + err = -EIO; + } else ntfs_error(vi->i_sb, "Failed to lookup attribute in " - "inode 0x%lx (error code %d).", - vi->i_ino, err); - goto err_out; + "inode 0x%lx (error code %d).%s", + vi->i_ino, err, te); + goto old_bad_out; } + m = ctx->mrec; a = ctx->attr; - /* If the size has not changed there is nothing to do. */ - if (ntfs_attr_size(a) == i_size_read(vi)) - goto done; - // TODO: Implement the truncate... - ntfs_error(vi->i_sb, "Inode size has changed but this is not " - "implemented yet. Resetting inode size to old value. " - " This is most likely a bug in the ntfs driver!"); - i_size_write(vi, ntfs_attr_size(a)); -done: + /* + * The i_size of the vfs inode is the new size for the attribute value. + */ + new_size = i_size_read(vi); + /* The current size of the attribute value is the old size. */ + old_size = ntfs_attr_size(a); + /* Calculate the new allocated size. */ + if (NInoNonResident(ni)) + new_alloc_size = (new_size + vol->cluster_size - 1) & + ~(s64)vol->cluster_size_mask; + else + new_alloc_size = (new_size + 7) & ~7; + /* The current allocated size is the old allocated size. */ + read_lock_irqsave(&ni->size_lock, flags); + old_alloc_size = ni->allocated_size; + read_unlock_irqrestore(&ni->size_lock, flags); + /* + * The change in the file size. This will be 0 if no change, >0 if the + * size is growing, and <0 if the size is shrinking. + */ + size_change = -1; + if (new_size - old_size >= 0) { + size_change = 1; + if (new_size == old_size) + size_change = 0; + } + /* As above for the allocated size. */ + alloc_change = -1; + if (new_alloc_size - old_alloc_size >= 0) { + alloc_change = 1; + if (new_alloc_size == old_alloc_size) + alloc_change = 0; + } + /* + * If neither the size nor the allocation are being changed there is + * nothing to do. + */ + if (!size_change && !alloc_change) + goto unm_done; + /* If the size is changing, check if new size is allowed in $AttrDef. */ + if (size_change) { + err = ntfs_attr_size_bounds_check(vol, ni->type, new_size); + if (unlikely(err)) { + if (err == -ERANGE) { + ntfs_error(vol->sb, "Truncate would cause the " + "inode 0x%lx to %simum size " + "for its attribute type " + "(0x%x). Aborting truncate.", + vi->i_ino, + new_size > old_size ? "exceed " + "the max" : "go under the min", + le32_to_cpu(ni->type)); + err = -EFBIG; + } else { + ntfs_error(vol->sb, "Inode 0x%lx has unknown " + "attribute type 0x%x. " + "Aborting truncate.", + vi->i_ino, + le32_to_cpu(ni->type)); + err = -EIO; + } + /* Reset the vfs inode size to the old size. */ + i_size_write(vi, old_size); + goto err_out; + } + } + if (NInoCompressed(ni) || NInoEncrypted(ni)) { + ntfs_warning(vi->i_sb, "Changes in inode size are not " + "supported yet for %s files, ignoring.", + NInoCompressed(ni) ? "compressed" : + "encrypted"); + err = -EOPNOTSUPP; + goto bad_out; + } + if (a->non_resident) + goto do_non_resident_truncate; + BUG_ON(NInoNonResident(ni)); + /* Resize the attribute record to best fit the new attribute size. */ + if (new_size < vol->mft_record_size && + !ntfs_resident_attr_value_resize(m, a, new_size)) { + unsigned long flags; + + /* The resize succeeded! */ + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + write_lock_irqsave(&ni->size_lock, flags); + /* Update the sizes in the ntfs inode and all is done. */ + ni->allocated_size = le32_to_cpu(a->length) - + le16_to_cpu(a->data.resident.value_offset); + /* + * Note ntfs_resident_attr_value_resize() has already done any + * necessary data clearing in the attribute record. When the + * file is being shrunk vmtruncate() will already have cleared + * the top part of the last partial page, i.e. since this is + * the resident case this is the page with index 0. However, + * when the file is being expanded, the page cache page data + * between the old data_size, i.e. old_size, and the new_size + * has not been zeroed. Fortunately, we do not need to zero it + * either since on one hand it will either already be zero due + * to both readpage and writepage clearing partial page data + * beyond i_size in which case there is nothing to do or in the + * case of the file being mmap()ped at the same time, POSIX + * specifies that the behaviour is unspecified thus we do not + * have to do anything. This means that in our implementation + * in the rare case that the file is mmap()ped and a write + * occured into the mmap()ped region just beyond the file size + * and writepage has not yet been called to write out the page + * (which would clear the area beyond the file size) and we now + * extend the file size to incorporate this dirty region + * outside the file size, a write of the page would result in + * this data being written to disk instead of being cleared. + * Given both POSIX and the Linux mmap(2) man page specify that + * this corner case is undefined, we choose to leave it like + * that as this is much simpler for us as we cannot lock the + * relevant page now since we are holding too many ntfs locks + * which would result in a lock reversal deadlock. + */ + ni->initialized_size = new_size; + write_unlock_irqrestore(&ni->size_lock, flags); + goto unm_done; + } + /* If the above resize failed, this must be an attribute extension. */ + BUG_ON(size_change < 0); + /* + * We have to drop all the locks so we can call + * ntfs_attr_make_non_resident(). This could be optimised by try- + * locking the first page cache page and only if that fails dropping + * the locks, locking the page, and redoing all the locking and + * lookups. While this would be a huge optimisation, it is not worth + * it as this is definitely a slow code path as it only ever can happen + * once for any given file. + */ ntfs_attr_put_search_ctx(ctx); - unmap_mft_record(ni); - NInoClearTruncateFailed(ni); - ntfs_debug("Done."); - return 0; -err_out: - if (err != -ENOMEM) { + unmap_mft_record(base_ni); + up_write(&ni->runlist.lock); + /* + * Not enough space in the mft record, try to make the attribute + * non-resident and if successful restart the truncation process. + */ + err = ntfs_attr_make_non_resident(ni, old_size); + if (likely(!err)) + goto retry_truncate; + /* + * Could not make non-resident. If this is due to this not being + * permitted for this attribute type or there not being enough space, + * try to make other attributes non-resident. Otherwise fail. + */ + if (unlikely(err != -EPERM && err != -ENOSPC)) { + ntfs_error(vol->sb, "Cannot truncate inode 0x%lx, attribute " + "type 0x%x, because the conversion from " + "resident to non-resident attribute failed " + "with error code %i.", vi->i_ino, + (unsigned)le32_to_cpu(ni->type), err); + if (err != -ENOMEM) + err = -EIO; + goto conv_err_out; + } + /* TODO: Not implemented from here, abort. */ + if (err == -ENOSPC) + ntfs_error(vol->sb, "Not enough space in the mft record/on " + "disk for the non-resident attribute value. " + "This case is not implemented yet."); + else /* if (err == -EPERM) */ + ntfs_error(vol->sb, "This attribute type may not be " + "non-resident. This case is not implemented " + "yet."); + err = -EOPNOTSUPP; + goto conv_err_out; +#if 0 + // TODO: Attempt to make other attributes non-resident. + if (!err) + goto do_resident_extend; + /* + * Both the attribute list attribute and the standard information + * attribute must remain in the base inode. Thus, if this is one of + * these attributes, we have to try to move other attributes out into + * extent mft records instead. + */ + if (ni->type == AT_ATTRIBUTE_LIST || + ni->type == AT_STANDARD_INFORMATION) { + // TODO: Attempt to move other attributes into extent mft + // records. + err = -EOPNOTSUPP; + if (!err) + goto do_resident_extend; + goto err_out; + } + // TODO: Attempt to move this attribute to an extent mft record, but + // only if it is not already the only attribute in an mft record in + // which case there would be nothing to gain. + err = -EOPNOTSUPP; + if (!err) + goto do_resident_extend; + /* There is nothing we can do to make enough space. )-: */ + goto err_out; +#endif +do_non_resident_truncate: + BUG_ON(!NInoNonResident(ni)); + if (alloc_change < 0) { + highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn); + if (highest_vcn > 0 && + old_alloc_size >> vol->cluster_size_bits > + highest_vcn + 1) { + /* + * This attribute has multiple extents. Not yet + * supported. + */ + ntfs_error(vol->sb, "Cannot truncate inode 0x%lx, " + "attribute type 0x%x, because the " + "attribute is highly fragmented (it " + "consists of multiple extents) and " + "this case is not implemented yet.", + vi->i_ino, + (unsigned)le32_to_cpu(ni->type)); + err = -EOPNOTSUPP; + goto bad_out; + } + } + /* + * If the size is shrinking, need to reduce the initialized_size and + * the data_size before reducing the allocation. + */ + if (size_change < 0) { + /* + * Make the valid size smaller (i_size is already up-to-date). + */ + write_lock_irqsave(&ni->size_lock, flags); + if (new_size < ni->initialized_size) { + ni->initialized_size = new_size; + a->data.non_resident.initialized_size = + cpu_to_sle64(new_size); + } + a->data.non_resident.data_size = cpu_to_sle64(new_size); + write_unlock_irqrestore(&ni->size_lock, flags); + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + /* If the allocated size is not changing, we are done. */ + if (!alloc_change) + goto unm_done; + /* + * If the size is shrinking it makes no sense for the + * allocation to be growing. + */ + BUG_ON(alloc_change > 0); + } else /* if (size_change >= 0) */ { + /* + * The file size is growing or staying the same but the + * allocation can be shrinking, growing or staying the same. + */ + if (alloc_change > 0) { + /* + * We need to extend the allocation and possibly update + * the data size. If we are updating the data size, + * since we are not touching the initialized_size we do + * not need to worry about the actual data on disk. + * And as far as the page cache is concerned, there + * will be no pages beyond the old data size and any + * partial region in the last page between the old and + * new data size (or the end of the page if the new + * data size is outside the page) does not need to be + * modified as explained above for the resident + * attribute truncate case. To do this, we simply drop + * the locks we hold and leave all the work to our + * friendly helper ntfs_attr_extend_allocation(). + */ + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(base_ni); + up_write(&ni->runlist.lock); + err = ntfs_attr_extend_allocation(ni, new_size, + size_change > 0 ? new_size : -1, -1); + /* + * ntfs_attr_extend_allocation() will have done error + * output already. + */ + goto done; + } + if (!alloc_change) + goto alloc_done; + } + /* alloc_change < 0 */ + /* Free the clusters. */ + nr_freed = ntfs_cluster_free(ni, new_alloc_size >> + vol->cluster_size_bits, -1, ctx); + m = ctx->mrec; + a = ctx->attr; + if (unlikely(nr_freed < 0)) { + ntfs_error(vol->sb, "Failed to release cluster(s) (error code " + "%lli). Unmount and run chkdsk to recover " + "the lost cluster(s).", (long long)nr_freed); NVolSetErrors(vol); + nr_freed = 0; + } + /* Truncate the runlist. */ + err = ntfs_rl_truncate_nolock(vol, &ni->runlist, + new_alloc_size >> vol->cluster_size_bits); + /* + * If the runlist truncation failed and/or the search context is no + * longer valid, we cannot resize the attribute record or build the + * mapping pairs array thus we mark the inode bad so that no access to + * the freed clusters can happen. + */ + if (unlikely(err || IS_ERR(m))) { + ntfs_error(vol->sb, "Failed to %s (error code %li).%s", + IS_ERR(m) ? + "restore attribute search context" : + "truncate attribute runlist", + IS_ERR(m) ? PTR_ERR(m) : err, es); + err = -EIO; + goto bad_out; + } + /* Get the size for the shrunk mapping pairs array for the runlist. */ + mp_size = ntfs_get_size_for_mapping_pairs(vol, ni->runlist.rl, 0, -1); + if (unlikely(mp_size <= 0)) { + ntfs_error(vol->sb, "Cannot shrink allocation of inode 0x%lx, " + "attribute type 0x%x, because determining the " + "size for the mapping pairs failed with error " + "code %i.%s", vi->i_ino, + (unsigned)le32_to_cpu(ni->type), mp_size, es); + err = -EIO; + goto bad_out; + } + /* + * Shrink the attribute record for the new mapping pairs array. Note, + * this cannot fail since we are making the attribute smaller thus by + * definition there is enough space to do so. + */ + attr_len = le32_to_cpu(a->length); + err = ntfs_attr_record_resize(m, a, mp_size + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset)); + BUG_ON(err); + /* + * Generate the mapping pairs array directly into the attribute record. + */ + err = ntfs_mapping_pairs_build(vol, (u8*)a + + le16_to_cpu(a->data.non_resident.mapping_pairs_offset), + mp_size, ni->runlist.rl, 0, -1, NULL); + if (unlikely(err)) { + ntfs_error(vol->sb, "Cannot shrink allocation of inode 0x%lx, " + "attribute type 0x%x, because building the " + "mapping pairs failed with error code %i.%s", + vi->i_ino, (unsigned)le32_to_cpu(ni->type), + err, es); + err = -EIO; + goto bad_out; + } + /* Update the allocated/compressed size as well as the highest vcn. */ + a->data.non_resident.highest_vcn = cpu_to_sle64((new_alloc_size >> + vol->cluster_size_bits) - 1); + write_lock_irqsave(&ni->size_lock, flags); + ni->allocated_size = new_alloc_size; + a->data.non_resident.allocated_size = cpu_to_sle64(new_alloc_size); + if (NInoSparse(ni) || NInoCompressed(ni)) { + if (nr_freed) { + ni->itype.compressed.size -= nr_freed << + vol->cluster_size_bits; + BUG_ON(ni->itype.compressed.size < 0); + a->data.non_resident.compressed_size = cpu_to_sle64( + ni->itype.compressed.size); + vi->i_blocks = ni->itype.compressed.size >> 9; + } + } else + vi->i_blocks = new_alloc_size >> 9; + write_unlock_irqrestore(&ni->size_lock, flags); + /* + * We have shrunk the allocation. If this is a shrinking truncate we + * have already dealt with the initialized_size and the data_size above + * and we are done. If the truncate is only changing the allocation + * and not the data_size, we are also done. If this is an extending + * truncate, need to extend the data_size now which is ensured by the + * fact that @size_change is positive. + */ +alloc_done: + /* + * If the size is growing, need to update it now. If it is shrinking, + * we have already updated it above (before the allocation change). + */ + if (size_change > 0) + a->data.non_resident.data_size = cpu_to_sle64(new_size); + /* Ensure the modified mft record is written out. */ + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); +unm_done: + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(base_ni); + up_write(&ni->runlist.lock); +done: + /* Update the mtime and ctime on the base inode. */ + inode_update_time(VFS_I(base_ni), 1); + if (likely(!err)) { + NInoClearTruncateFailed(ni); + ntfs_debug("Done."); + } + return err; +old_bad_out: + old_size = -1; +bad_out: + if (err != -ENOMEM && err != -EOPNOTSUPP) { make_bad_inode(vi); + make_bad_inode(VFS_I(base_ni)); + NVolSetErrors(vol); } + if (err != -EOPNOTSUPP) + NInoSetTruncateFailed(ni); + else if (old_size >= 0) + i_size_write(vi, old_size); +err_out: if (ctx) ntfs_attr_put_search_ctx(ctx); if (m) - unmap_mft_record(ni); - NInoSetTruncateFailed(ni); + unmap_mft_record(base_ni); + up_write(&ni->runlist.lock); +out: + ntfs_debug("Failed. Returning error code %i.", err); return err; +conv_err_out: + if (err != -ENOMEM && err != -EOPNOTSUPP) { + make_bad_inode(vi); + make_bad_inode(VFS_I(base_ni)); + NVolSetErrors(vol); + } + if (err != -EOPNOTSUPP) + NInoSetTruncateFailed(ni); + else + i_size_write(vi, old_size); + goto out; } /** -- 2.20.1