Commit dd072330 authored by Anton Altaparmakov's avatar Anton Altaparmakov
Browse files

NTFS: Implement fs/ntfs/inode.[hc]::ntfs_truncate(). It only supports


      uncompressed and unencrypted files.
Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
parent 2d86829b
......@@ -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.
......
......@@ -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;
}
/**
......
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