--- /dev/null
+/**
+ * attrib.c - NTFS attribute operations. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
+ * 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/sched.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+
+#include "attrib.h"
+#include "debug.h"
+#include "layout.h"
+#include "lcnalloc.h"
+#include "malloc.h"
+#include "mft.h"
+#include "ntfs.h"
+#include "types.h"
+
+/**
+ * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode
+ * @ni: ntfs inode for which to map (part of) a runlist
+ * @vcn: map runlist part containing this vcn
+ * @ctx: active attribute search context if present or NULL if not
+ *
+ * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
+ *
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record. This is needed when ntfs_map_runlist_nolock() encounters unmapped
+ * runlist fragments and allows their mapping. If you do not have the mft
+ * record mapped, you can specify @ctx as NULL and ntfs_map_runlist_nolock()
+ * will perform the necessary mapping and unmapping.
+ *
+ * Note, ntfs_map_runlist_nolock() saves the state of @ctx on entry and
+ * restores it before returning. Thus, @ctx will be left pointing to the same
+ * attribute on return as on entry. However, the actual pointers in @ctx may
+ * point to different memory locations on return, so you must remember to reset
+ * any cached pointers from the @ctx, i.e. after the call to
+ * ntfs_map_runlist_nolock(), you will probably want to do:
+ * m = ctx->mrec;
+ * a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ *
+ * Return 0 on success and -errno on error. There is one special error code
+ * which is not an error as such. This is -ENOENT. It means that @vcn is out
+ * of bounds of the runlist.
+ *
+ * Note the runlist can be NULL after this function returns if @vcn is zero and
+ * the attribute has zero allocated size, i.e. there simply is no runlist.
+ *
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
+ * is no longer valid, i.e. you need to either call
+ * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ * In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ * why the mapping of the old inode failed.
+ *
+ * Locking: - The runlist described by @ni must be locked for writing on entry
+ * and is locked on return. Note the runlist will be modified.
+ * - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ * entry and it will be left unmapped on return.
+ * - If @ctx is not NULL, the base mft record must be mapped on entry
+ * and it will be left mapped on return.
+ */
+int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx)
+{
+ VCN end_vcn;
+ unsigned long flags;
+ ntfs_inode *base_ni;
+ MFT_RECORD *m;
+ ATTR_RECORD *a;
+ runlist_element *rl;
+ struct page *put_this_page = NULL;
+ int err = 0;
+ bool ctx_is_temporary, ctx_needs_reset;
+ ntfs_attr_search_ctx old_ctx = { NULL, };
+
+ ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
+ (unsigned long long)vcn);
+ if (!NInoAttr(ni))
+ base_ni = ni;
+ else
+ base_ni = ni->ext.base_ntfs_ino;
+ if (!ctx) {
+ ctx_is_temporary = ctx_needs_reset = true;
+ m = map_mft_record(base_ni);
+ if (IS_ERR(m))
+ return PTR_ERR(m);
+ ctx = ntfs_attr_get_search_ctx(base_ni, m);
+ if (unlikely(!ctx)) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ } else {
+ VCN allocated_size_vcn;
+
+ BUG_ON(IS_ERR(ctx->mrec));
+ a = ctx->attr;
+ BUG_ON(!a->non_resident);
+ ctx_is_temporary = false;
+ end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
+ read_lock_irqsave(&ni->size_lock, flags);
+ allocated_size_vcn = ni->allocated_size >>
+ ni->vol->cluster_size_bits;
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
+ end_vcn = allocated_size_vcn - 1;
+ /*
+ * If we already have the attribute extent containing @vcn in
+ * @ctx, no need to look it up again. We slightly cheat in
+ * that if vcn exceeds the allocated size, we will refuse to
+ * map the runlist below, so there is definitely no need to get
+ * the right attribute extent.
+ */
+ if (vcn >= allocated_size_vcn || (a->type == ni->type &&
+ a->name_length == ni->name_len &&
+ !memcmp((u8*)a + le16_to_cpu(a->name_offset),
+ ni->name, ni->name_len) &&
+ sle64_to_cpu(a->data.non_resident.lowest_vcn)
+ <= vcn && end_vcn >= vcn))
+ ctx_needs_reset = false;
+ else {
+ /* Save the old search context. */
+ old_ctx = *ctx;
+ /*
+ * If the currently mapped (extent) inode is not the
+ * base inode we will unmap it when we reinitialize the
+ * search context which means we need to get a
+ * reference to the page containing the mapped mft
+ * record so we do not accidentally drop changes to the
+ * mft record when it has not been marked dirty yet.
+ */
+ if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
+ old_ctx.base_ntfs_ino) {
+ put_this_page = old_ctx.ntfs_ino->page;
+ page_cache_get(put_this_page);
+ }
+ /*
+ * Reinitialize the search context so we can lookup the
+ * needed attribute extent.
+ */
+ ntfs_attr_reinit_search_ctx(ctx);
+ ctx_needs_reset = true;
+ }
+ }
+ if (ctx_needs_reset) {
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, vcn, NULL, 0, ctx);
+ if (unlikely(err)) {
+ if (err == -ENOENT)
+ err = -EIO;
+ goto err_out;
+ }
+ BUG_ON(!ctx->attr->non_resident);
+ }
+ a = ctx->attr;
+ /*
+ * Only decompress the mapping pairs if @vcn is inside it. Otherwise
+ * we get into problems when we try to map an out of bounds vcn because
+ * we then try to map the already mapped runlist fragment and
+ * ntfs_mapping_pairs_decompress() fails.
+ */
+ end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
+ if (unlikely(vcn && vcn >= end_vcn)) {
+ err = -ENOENT;
+ goto err_out;
+ }
+ rl = ntfs_mapping_pairs_decompress(ni->vol, a, ni->runlist.rl);
+ if (IS_ERR(rl))
+ err = PTR_ERR(rl);
+ else
+ ni->runlist.rl = rl;
+err_out:
+ if (ctx_is_temporary) {
+ if (likely(ctx))
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(base_ni);
+ } else if (ctx_needs_reset) {
+ /*
+ * If there is no attribute list, restoring the search context
+ * is accomplished simply by copying the saved context back over
+ * the caller supplied context. If there is an attribute list,
+ * things are more complicated as we need to deal with mapping
+ * of mft records and resulting potential changes in pointers.
+ */
+ if (NInoAttrList(base_ni)) {
+ /*
+ * If the currently mapped (extent) inode is not the
+ * one we had before, we need to unmap it and map the
+ * old one.
+ */
+ if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
+ /*
+ * If the currently mapped inode is not the
+ * base inode, unmap it.
+ */
+ if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
+ ctx->base_ntfs_ino) {
+ unmap_extent_mft_record(ctx->ntfs_ino);
+ ctx->mrec = ctx->base_mrec;
+ BUG_ON(!ctx->mrec);
+ }
+ /*
+ * If the old mapped inode is not the base
+ * inode, map it.
+ */
+ if (old_ctx.base_ntfs_ino &&
+ old_ctx.ntfs_ino !=
+ old_ctx.base_ntfs_ino) {
+retry_map:
+ ctx->mrec = map_mft_record(
+ old_ctx.ntfs_ino);
+ /*
+ * Something bad has happened. If out
+ * of memory retry till it succeeds.
+ * Any other errors are fatal and we
+ * return the error code in ctx->mrec.
+ * Let the caller deal with it... We
+ * just need to fudge things so the
+ * caller can reinit and/or put the
+ * search context safely.
+ */
+ if (IS_ERR(ctx->mrec)) {
+ if (PTR_ERR(ctx->mrec) ==
+ -ENOMEM) {
+ schedule();
+ goto retry_map;
+ } else
+ old_ctx.ntfs_ino =
+ old_ctx.
+ base_ntfs_ino;
+ }
+ }
+ }
+ /* Update the changed pointers in the saved context. */
+ if (ctx->mrec != old_ctx.mrec) {
+ if (!IS_ERR(ctx->mrec))
+ old_ctx.attr = (ATTR_RECORD*)(
+ (u8*)ctx->mrec +
+ ((u8*)old_ctx.attr -
+ (u8*)old_ctx.mrec));
+ old_ctx.mrec = ctx->mrec;
+ }
+ }
+ /* Restore the search context to the saved one. */
+ *ctx = old_ctx;
+ /*
+ * We drop the reference on the page we took earlier. In the
+ * case that IS_ERR(ctx->mrec) is true this means we might lose
+ * some changes to the mft record that had been made between
+ * the last time it was marked dirty/written out and now. This
+ * at this stage is not a problem as the mapping error is fatal
+ * enough that the mft record cannot be written out anyway and
+ * the caller is very likely to shutdown the whole inode
+ * immediately and mark the volume dirty for chkdsk to pick up
+ * the pieces anyway.
+ */
+ if (put_this_page)
+ page_cache_release(put_this_page);
+ }
+ return err;
+}
+
+/**
+ * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode
+ * @ni: ntfs inode for which to map (part of) a runlist
+ * @vcn: map runlist part containing this vcn
+ *
+ * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
+ *
+ * Return 0 on success and -errno on error. There is one special error code
+ * which is not an error as such. This is -ENOENT. It means that @vcn is out
+ * of bounds of the runlist.
+ *
+ * Locking: - The runlist must be unlocked on entry and is unlocked on return.
+ * - This function takes the runlist lock for writing and may modify
+ * the runlist.
+ */
+int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
+{
+ int err = 0;
+
+ down_write(&ni->runlist.lock);
+ /* Make sure someone else didn't do the work while we were sleeping. */
+ if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <=
+ LCN_RL_NOT_MAPPED))
+ err = ntfs_map_runlist_nolock(ni, vcn, NULL);
+ up_write(&ni->runlist.lock);
+ return err;
+}
+
+/**
+ * ntfs_attr_vcn_to_lcn_nolock - convert a vcn into a lcn given an ntfs inode
+ * @ni: ntfs inode of the attribute whose runlist to search
+ * @vcn: vcn to convert
+ * @write_locked: true if the runlist is locked for writing
+ *
+ * Find the virtual cluster number @vcn in the runlist of the ntfs attribute
+ * described by the ntfs inode @ni and return the corresponding logical cluster
+ * number (lcn).
+ *
+ * If the @vcn is not mapped yet, the attempt is made to map the attribute
+ * extent containing the @vcn and the vcn to lcn conversion is retried.
+ *
+ * If @write_locked is true the caller has locked the runlist for writing and
+ * if false for reading.
+ *
+ * Since lcns must be >= 0, we use negative return codes with special meaning:
+ *
+ * Return code Meaning / Description
+ * ==========================================
+ * LCN_HOLE Hole / not allocated on disk.
+ * LCN_ENOENT There is no such vcn in the runlist, i.e. @vcn is out of bounds.
+ * LCN_ENOMEM Not enough memory to map runlist.
+ * LCN_EIO Critical error (runlist/file is corrupt, i/o error, etc).
+ *
+ * Locking: - The runlist must be locked on entry and is left locked on return.
+ * - If @write_locked is 'false', i.e. the runlist is locked for reading,
+ * the lock may be dropped inside the function so you cannot rely on
+ * the runlist still being the same when this function returns.
+ */
+LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
+ const bool write_locked)
+{
+ LCN lcn;
+ unsigned long flags;
+ bool is_retry = false;
+
+ BUG_ON(!ni);
+ ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.",
+ ni->mft_no, (unsigned long long)vcn,
+ write_locked ? "write" : "read");
+ BUG_ON(!NInoNonResident(ni));
+ BUG_ON(vcn < 0);
+ if (!ni->runlist.rl) {
+ read_lock_irqsave(&ni->size_lock, flags);
+ if (!ni->allocated_size) {
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ return LCN_ENOENT;
+ }
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ }
+retry_remap:
+ /* Convert vcn to lcn. If that fails map the runlist and retry once. */
+ lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn);
+ if (likely(lcn >= LCN_HOLE)) {
+ ntfs_debug("Done, lcn 0x%llx.", (long long)lcn);
+ return lcn;
+ }
+ if (lcn != LCN_RL_NOT_MAPPED) {
+ if (lcn != LCN_ENOENT)
+ lcn = LCN_EIO;
+ } else if (!is_retry) {
+ int err;
+
+ if (!write_locked) {
+ up_read(&ni->runlist.lock);
+ down_write(&ni->runlist.lock);
+ if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) !=
+ LCN_RL_NOT_MAPPED)) {
+ up_write(&ni->runlist.lock);
+ down_read(&ni->runlist.lock);
+ goto retry_remap;
+ }
+ }
+ err = ntfs_map_runlist_nolock(ni, vcn, NULL);
+ if (!write_locked) {
+ up_write(&ni->runlist.lock);
+ down_read(&ni->runlist.lock);
+ }
+ if (likely(!err)) {
+ is_retry = true;
+ goto retry_remap;
+ }
+ if (err == -ENOENT)
+ lcn = LCN_ENOENT;
+ else if (err == -ENOMEM)
+ lcn = LCN_ENOMEM;
+ else
+ lcn = LCN_EIO;
+ }
+ if (lcn != LCN_ENOENT)
+ ntfs_error(ni->vol->sb, "Failed with error code %lli.",
+ (long long)lcn);
+ return lcn;
+}
+
+/**
+ * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode
+ * @ni: ntfs inode describing the runlist to search
+ * @vcn: vcn to find
+ * @ctx: active attribute search context if present or NULL if not
+ *
+ * Find the virtual cluster number @vcn in the runlist described by the ntfs
+ * inode @ni and return the address of the runlist element containing the @vcn.
+ *
+ * If the @vcn is not mapped yet, the attempt is made to map the attribute
+ * extent containing the @vcn and the vcn to lcn conversion is retried.
+ *
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record. This is needed when ntfs_attr_find_vcn_nolock() encounters unmapped
+ * runlist fragments and allows their mapping. If you do not have the mft
+ * record mapped, you can specify @ctx as NULL and ntfs_attr_find_vcn_nolock()
+ * will perform the necessary mapping and unmapping.
+ *
+ * Note, ntfs_attr_find_vcn_nolock() saves the state of @ctx on entry and
+ * restores it before returning. Thus, @ctx will be left pointing to the same
+ * attribute on return as on entry. However, the actual pointers in @ctx may
+ * point to different memory locations on return, so you must remember to reset
+ * any cached pointers from the @ctx, i.e. after the call to
+ * ntfs_attr_find_vcn_nolock(), you will probably want to do:
+ * m = ctx->mrec;
+ * a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ * Note you need to distinguish between the lcn of the returned runlist element
+ * being >= 0 and LCN_HOLE. In the later case you have to return zeroes on
+ * read and allocate clusters on write.
+ *
+ * Return the runlist element containing the @vcn on success and
+ * ERR_PTR(-errno) on error. You need to test the return value with IS_ERR()
+ * to decide if the return is success or failure and PTR_ERR() to get to the
+ * error code if IS_ERR() is true.
+ *
+ * The possible error return codes are:
+ * -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds.
+ * -ENOMEM - Not enough memory to map runlist.
+ * -EIO - Critical error (runlist/file is corrupt, i/o error, etc).
+ *
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ * returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
+ * is no longer valid, i.e. you need to either call
+ * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ * In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ * why the mapping of the old inode failed.
+ *
+ * Locking: - The runlist described by @ni must be locked for writing on entry
+ * and is locked on return. Note the runlist may be modified when
+ * needed runlist fragments need to be mapped.
+ * - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ * entry and it will be left unmapped on return.
+ * - If @ctx is not NULL, the base mft record must be mapped on entry
+ * and it will be left mapped on return.
+ */
+runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
+ ntfs_attr_search_ctx *ctx)
+{
+ unsigned long flags;
+ runlist_element *rl;
+ int err = 0;
+ bool is_retry = false;
+
+ BUG_ON(!ni);
+ ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, with%s ctx.",
+ ni->mft_no, (unsigned long long)vcn, ctx ? "" : "out");
+ BUG_ON(!NInoNonResident(ni));
+ BUG_ON(vcn < 0);
+ if (!ni->runlist.rl) {
+ read_lock_irqsave(&ni->size_lock, flags);
+ if (!ni->allocated_size) {
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ return ERR_PTR(-ENOENT);
+ }
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ }
+retry_remap:
+ rl = ni->runlist.rl;
+ if (likely(rl && vcn >= rl[0].vcn)) {
+ while (likely(rl->length)) {
+ if (unlikely(vcn < rl[1].vcn)) {
+ if (likely(rl->lcn >= LCN_HOLE)) {
+ ntfs_debug("Done.");
+ return rl;
+ }
+ break;
+ }
+ rl++;
+ }
+ if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) {
+ if (likely(rl->lcn == LCN_ENOENT))
+ err = -ENOENT;
+ else
+ err = -EIO;
+ }
+ }
+ if (!err && !is_retry) {
+ /*
+ * If the search context is invalid we cannot map the unmapped
+ * region.
+ */
+ if (IS_ERR(ctx->mrec))
+ err = PTR_ERR(ctx->mrec);
+ else {
+ /*
+ * The @vcn is in an unmapped region, map the runlist
+ * and retry.
+ */
+ err = ntfs_map_runlist_nolock(ni, vcn, ctx);
+ if (likely(!err)) {
+ is_retry = true;
+ goto retry_remap;
+ }
+ }
+ if (err == -EINVAL)
+ err = -EIO;
+ } else if (!err)
+ err = -EIO;
+ if (err != -ENOENT)
+ ntfs_error(ni->vol->sb, "Failed with error code %i.", err);
+ return ERR_PTR(err);
+}
+
+/**
+ * ntfs_attr_find - find (next) attribute in mft record
+ * @type: attribute type to find
+ * @name: attribute name to find (optional, i.e. NULL means don't care)
+ * @name_len: attribute name length (only needed if @name present)
+ * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
+ * @val: attribute value to find (optional, resident attributes only)
+ * @val_len: attribute value length
+ * @ctx: search context with mft record and attribute to search from
+ *
+ * You should not need to call this function directly. Use ntfs_attr_lookup()
+ * instead.
+ *
+ * ntfs_attr_find() takes a search context @ctx as parameter and searches the
+ * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an
+ * attribute of @type, optionally @name and @val.
+ *
+ * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will
+ * point to the found attribute.
+ *
+ * If the attribute is not found, ntfs_attr_find() returns -ENOENT and
+ * @ctx->attr will point to the attribute before which the attribute being
+ * searched for would need to be inserted if such an action were to be desired.
+ *
+ * On actual error, ntfs_attr_find() returns -EIO. In this case @ctx->attr is
+ * undefined and in particular do not rely on it not changing.
+ *
+ * If @ctx->is_first is 'true', the search begins with @ctx->attr itself. If it
+ * is 'false', the search begins after @ctx->attr.
+ *
+ * If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and
+ * @ctx->ntfs_ino must be set to the ntfs inode to which the mft record
+ * @ctx->mrec belongs. This is so we can get at the ntfs volume and hence at
+ * the upcase table. If @ic is CASE_SENSITIVE, the comparison is case
+ * sensitive. When @name is present, @name_len is the @name length in Unicode
+ * characters.
+ *
+ * If @name is not present (NULL), we assume that the unnamed attribute is
+ * being searched for.
+ *
+ * Finally, the resident attribute value @val is looked for, if present. If
+ * @val is not present (NULL), @val_len is ignored.
+ *
+ * ntfs_attr_find() only searches the specified mft record and it ignores the
+ * presence of an attribute list attribute (unless it is the one being searched
+ * for, obviously). If you need to take attribute lists into consideration,
+ * use ntfs_attr_lookup() instead (see below). This also means that you cannot
+ * use ntfs_attr_find() to search for extent records of non-resident
+ * attributes, as extents with lowest_vcn != 0 are usually described by the
+ * attribute list attribute only. - Note that it is possible that the first
+ * extent is only in the attribute list while the last extent is in the base
+ * mft record, so do not rely on being able to find the first extent in the
+ * base mft record.
+ *
+ * Warning: Never use @val when looking for attribute types which can be
+ * non-resident as this most likely will result in a crash!
+ */
+static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name,
+ const u32 name_len, const IGNORE_CASE_BOOL ic,
+ const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
+{
+ ATTR_RECORD *a;
+ ntfs_volume *vol = ctx->ntfs_ino->vol;
+ ntfschar *upcase = vol->upcase;
+ u32 upcase_len = vol->upcase_len;
+
+ /*
+ * Iterate over attributes in mft record starting at @ctx->attr, or the
+ * attribute following that, if @ctx->is_first is 'true'.
+ */
+ if (ctx->is_first) {
+ a = ctx->attr;
+ ctx->is_first = false;
+ } else
+ a = (ATTR_RECORD*)((u8*)ctx->attr +
+ le32_to_cpu(ctx->attr->length));
+ for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) {
+ if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec +
+ le32_to_cpu(ctx->mrec->bytes_allocated))
+ break;
+ ctx->attr = a;
+ if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) ||
+ a->type == AT_END))
+ return -ENOENT;
+ if (unlikely(!a->length))
+ break;
+ if (a->type != type)
+ continue;
+ /*
+ * If @name is present, compare the two names. If @name is
+ * missing, assume we want an unnamed attribute.
+ */
+ if (!name) {
+ /* The search failed if the found attribute is named. */
+ if (a->name_length)
+ return -ENOENT;
+ } else if (!ntfs_are_names_equal(name, name_len,
+ (ntfschar*)((u8*)a + le16_to_cpu(a->name_offset)),
+ a->name_length, ic, upcase, upcase_len)) {
+ register int rc;
+
+ rc = ntfs_collate_names(name, name_len,
+ (ntfschar*)((u8*)a +
+ le16_to_cpu(a->name_offset)),
+ a->name_length, 1, IGNORE_CASE,
+ upcase, upcase_len);
+ /*
+ * If @name collates before a->name, there is no
+ * matching attribute.
+ */
+ if (rc == -1)
+ return -ENOENT;
+ /* If the strings are not equal, continue search. */
+ if (rc)
+ continue;
+ rc = ntfs_collate_names(name, name_len,
+ (ntfschar*)((u8*)a +
+ le16_to_cpu(a->name_offset)),
+ a->name_length, 1, CASE_SENSITIVE,
+ upcase, upcase_len);
+ if (rc == -1)
+ return -ENOENT;
+ if (rc)
+ continue;
+ }
+ /*
+ * The names match or @name not present and attribute is
+ * unnamed. If no @val specified, we have found the attribute
+ * and are done.
+ */
+ if (!val)
+ return 0;
+ /* @val is present; compare values. */
+ else {
+ register int rc;
+
+ rc = memcmp(val, (u8*)a + le16_to_cpu(
+ a->data.resident.value_offset),
+ min_t(u32, val_len, le32_to_cpu(
+ a->data.resident.value_length)));
+ /*
+ * If @val collates before the current attribute's
+ * value, there is no matching attribute.
+ */
+ if (!rc) {
+ register u32 avl;
+
+ avl = le32_to_cpu(
+ a->data.resident.value_length);
+ if (val_len == avl)
+ return 0;
+ if (val_len < avl)
+ return -ENOENT;
+ } else if (rc < 0)
+ return -ENOENT;
+ }
+ }
+ ntfs_error(vol->sb, "Inode is corrupt. Run chkdsk.");
+ NVolSetErrors(vol);
+ return -EIO;
+}
+
+/**
+ * load_attribute_list - load an attribute list into memory
+ * @vol: ntfs volume from which to read
+ * @runlist: runlist of the attribute list
+ * @al_start: destination buffer
+ * @size: size of the destination buffer in bytes
+ * @initialized_size: initialized size of the attribute list
+ *
+ * Walk the runlist @runlist and load all clusters from it copying them into
+ * the linear buffer @al. The maximum number of bytes copied to @al is @size
+ * bytes. Note, @size does not need to be a multiple of the cluster size. If
+ * @initialized_size is less than @size, the region in @al between
+ * @initialized_size and @size will be zeroed and not read from disk.
+ *
+ * Return 0 on success or -errno on error.
+ */
+int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start,
+ const s64 size, const s64 initialized_size)
+{
+ LCN lcn;
+ u8 *al = al_start;
+ u8 *al_end = al + initialized_size;
+ runlist_element *rl;
+ struct buffer_head *bh;
+ struct super_block *sb;
+ unsigned long block_size;
+ unsigned long block, max_block;
+ int err = 0;
+ unsigned char block_size_bits;
+
+ ntfs_debug("Entering.");
+ if (!vol || !runlist || !al || size <= 0 || initialized_size < 0 ||
+ initialized_size > size)
+ return -EINVAL;
+ if (!initialized_size) {
+ memset(al, 0, size);
+ return 0;
+ }
+ sb = vol->sb;
+ block_size = sb->s_blocksize;
+ block_size_bits = sb->s_blocksize_bits;
+ down_read(&runlist->lock);
+ rl = runlist->rl;
+ if (!rl) {
+ ntfs_error(sb, "Cannot read attribute list since runlist is "
+ "missing.");
+ goto err_out;
+ }
+ /* Read all clusters specified by the runlist one run at a time. */
+ while (rl->length) {
+ lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn);
+ ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.",
+ (unsigned long long)rl->vcn,
+ (unsigned long long)lcn);
+ /* The attribute list cannot be sparse. */
+ if (lcn < 0) {
+ ntfs_error(sb, "ntfs_rl_vcn_to_lcn() failed. Cannot "
+ "read attribute list.");
+ goto err_out;
+ }
+ block = lcn << vol->cluster_size_bits >> block_size_bits;
+ /* Read the run from device in chunks of block_size bytes. */
+ max_block = block + (rl->length << vol->cluster_size_bits >>
+ block_size_bits);
+ ntfs_debug("max_block = 0x%lx.", max_block);
+ do {
+ ntfs_debug("Reading block = 0x%lx.", block);
+ bh = sb_bread(sb, block);
+ if (!bh) {
+ ntfs_error(sb, "sb_bread() failed. Cannot "
+ "read attribute list.");
+ goto err_out;
+ }
+ if (al + block_size >= al_end)
+ goto do_final;
+ memcpy(al, bh->b_data, block_size);
+ brelse(bh);
+ al += block_size;
+ } while (++block < max_block);
+ rl++;
+ }
+ if (initialized_size < size) {
+initialize:
+ memset(al_start + initialized_size, 0, size - initialized_size);
+ }
+done:
+ up_read(&runlist->lock);
+ return err;
+do_final:
+ if (al < al_end) {
+ /*
+ * Partial block.
+ *
+ * Note: The attribute list can be smaller than its allocation
+ * by multiple clusters. This has been encountered by at least
+ * two people running Windows XP, thus we cannot do any
+ * truncation sanity checking here. (AIA)
+ */
+ memcpy(al, bh->b_data, al_end - al);
+ brelse(bh);
+ if (initialized_size < size)
+ goto initialize;
+ goto done;
+ }
+ brelse(bh);
+ /* Real overflow! */
+ ntfs_error(sb, "Attribute list buffer overflow. Read attribute list "
+ "is truncated.");
+err_out:
+ err = -EIO;
+ goto done;
+}
+
+/**
+ * ntfs_external_attr_find - find an attribute in the attribute list of an inode
+ * @type: attribute type to find
+ * @name: attribute name to find (optional, i.e. NULL means don't care)
+ * @name_len: attribute name length (only needed if @name present)
+ * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
+ * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only)
+ * @val: attribute value to find (optional, resident attributes only)
+ * @val_len: attribute value length
+ * @ctx: search context with mft record and attribute to search from
+ *
+ * You should not need to call this function directly. Use ntfs_attr_lookup()
+ * instead.
+ *
+ * Find an attribute by searching the attribute list for the corresponding
+ * attribute list entry. Having found the entry, map the mft record if the
+ * attribute is in a different mft record/inode, ntfs_attr_find() the attribute
+ * in there and return it.
+ *
+ * On first search @ctx->ntfs_ino must be the base mft record and @ctx must
+ * have been obtained from a call to ntfs_attr_get_search_ctx(). On subsequent
+ * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is
+ * then the base inode).
+ *
+ * After finishing with the attribute/mft record you need to call
+ * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
+ * mapped inodes, etc).
+ *
+ * If the attribute is found, ntfs_external_attr_find() returns 0 and
+ * @ctx->attr will point to the found attribute. @ctx->mrec will point to the
+ * mft record in which @ctx->attr is located and @ctx->al_entry will point to
+ * the attribute list entry for the attribute.
+ *
+ * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and
+ * @ctx->attr will point to the attribute in the base mft record before which
+ * the attribute being searched for would need to be inserted if such an action
+ * were to be desired. @ctx->mrec will point to the mft record in which
+ * @ctx->attr is located and @ctx->al_entry will point to the attribute list
+ * entry of the attribute before which the attribute being searched for would
+ * need to be inserted if such an action were to be desired.
+ *
+ * Thus to insert the not found attribute, one wants to add the attribute to
+ * @ctx->mrec (the base mft record) and if there is not enough space, the
+ * attribute should be placed in a newly allocated extent mft record. The
+ * attribute list entry for the inserted attribute should be inserted in the
+ * attribute list attribute at @ctx->al_entry.
+ *
+ * On actual error, ntfs_external_attr_find() returns -EIO. In this case
+ * @ctx->attr is undefined and in particular do not rely on it not changing.
+ */
+static int ntfs_external_attr_find(const ATTR_TYPE type,
+ const ntfschar *name, const u32 name_len,
+ const IGNORE_CASE_BOOL ic, const VCN lowest_vcn,
+ const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
+{
+ ntfs_inode *base_ni, *ni;
+ ntfs_volume *vol;
+ ATTR_LIST_ENTRY *al_entry, *next_al_entry;
+ u8 *al_start, *al_end;
+ ATTR_RECORD *a;
+ ntfschar *al_name;
+ u32 al_name_len;
+ int err = 0;
+ static const char *es = " Unmount and run chkdsk.";
+
+ ni = ctx->ntfs_ino;
+ base_ni = ctx->base_ntfs_ino;
+ ntfs_debug("Entering for inode 0x%lx, type 0x%x.", ni->mft_no, type);
+ if (!base_ni) {
+ /* First call happens with the base mft record. */
+ base_ni = ctx->base_ntfs_ino = ctx->ntfs_ino;
+ ctx->base_mrec = ctx->mrec;
+ }
+ if (ni == base_ni)
+ ctx->base_attr = ctx->attr;
+ if (type == AT_END)
+ goto not_found;
+ vol = base_ni->vol;
+ al_start = base_ni->attr_list;
+ al_end = al_start + base_ni->attr_list_size;
+ if (!ctx->al_entry)
+ ctx->al_entry = (ATTR_LIST_ENTRY*)al_start;
+ /*
+ * Iterate over entries in attribute list starting at @ctx->al_entry,
+ * or the entry following that, if @ctx->is_first is 'true'.
+ */
+ if (ctx->is_first) {
+ al_entry = ctx->al_entry;
+ ctx->is_first = false;
+ } else
+ al_entry = (ATTR_LIST_ENTRY*)((u8*)ctx->al_entry +
+ le16_to_cpu(ctx->al_entry->length));
+ for (;; al_entry = next_al_entry) {
+ /* Out of bounds check. */
+ if ((u8*)al_entry < base_ni->attr_list ||
+ (u8*)al_entry > al_end)
+ break; /* Inode is corrupt. */
+ ctx->al_entry = al_entry;
+ /* Catch the end of the attribute list. */
+ if ((u8*)al_entry == al_end)
+ goto not_found;
+ if (!al_entry->length)
+ break;
+ if ((u8*)al_entry + 6 > al_end || (u8*)al_entry +
+ le16_to_cpu(al_entry->length) > al_end)
+ break;
+ next_al_entry = (ATTR_LIST_ENTRY*)((u8*)al_entry +
+ le16_to_cpu(al_entry->length));
+ if (le32_to_cpu(al_entry->type) > le32_to_cpu(type))
+ goto not_found;
+ if (type != al_entry->type)
+ continue;
+ /*
+ * If @name is present, compare the two names. If @name is
+ * missing, assume we want an unnamed attribute.
+ */
+ al_name_len = al_entry->name_length;
+ al_name = (ntfschar*)((u8*)al_entry + al_entry->name_offset);
+ if (!name) {
+ if (al_name_len)
+ goto not_found;
+ } else if (!ntfs_are_names_equal(al_name, al_name_len, name,
+ name_len, ic, vol->upcase, vol->upcase_len)) {
+ register int rc;
+
+ rc = ntfs_collate_names(name, name_len, al_name,
+ al_name_len, 1, IGNORE_CASE,
+ vol->upcase, vol->upcase_len);
+ /*
+ * If @name collates before al_name, there is no
+ * matching attribute.
+ */
+ if (rc == -1)
+ goto not_found;
+ /* If the strings are not equal, continue search. */
+ if (rc)
+ continue;
+ /*
+ * FIXME: Reverse engineering showed 0, IGNORE_CASE but
+ * that is inconsistent with ntfs_attr_find(). The
+ * subsequent rc checks were also different. Perhaps I
+ * made a mistake in one of the two. Need to recheck
+ * which is correct or at least see what is going on...
+ * (AIA)
+ */
+ rc = ntfs_collate_names(name, name_len, al_name,
+ al_name_len, 1, CASE_SENSITIVE,
+ vol->upcase, vol->upcase_len);
+ if (rc == -1)
+ goto not_found;
+ if (rc)
+ continue;
+ }
+ /*
+ * The names match or @name not present and attribute is
+ * unnamed. Now check @lowest_vcn. Continue search if the
+ * next attribute list entry still fits @lowest_vcn. Otherwise
+ * we have reached the right one or the search has failed.
+ */
+ if (lowest_vcn && (u8*)next_al_entry >= al_start &&
+ (u8*)next_al_entry + 6 < al_end &&
+ (u8*)next_al_entry + le16_to_cpu(
+ next_al_entry->length) <= al_end &&
+ sle64_to_cpu(next_al_entry->lowest_vcn) <=
+ lowest_vcn &&
+ next_al_entry->type == al_entry->type &&
+ next_al_entry->name_length == al_name_len &&
+ ntfs_are_names_equal((ntfschar*)((u8*)
+ next_al_entry +
+ next_al_entry->name_offset),
+ next_al_entry->name_length,
+ al_name, al_name_len, CASE_SENSITIVE,
+ vol->upcase, vol->upcase_len))
+ continue;
+ if (MREF_LE(al_entry->mft_reference) == ni->mft_no) {
+ if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) {
+ ntfs_error(vol->sb, "Found stale mft "
+ "reference in attribute list "
+ "of base inode 0x%lx.%s",
+ base_ni->mft_no, es);
+ err = -EIO;
+ break;
+ }
+ } else { /* Mft references do not match. */
+ /* If there is a mapped record unmap it first. */
+ if (ni != base_ni)
+ unmap_extent_mft_record(ni);
+ /* Do we want the base record back? */
+ if (MREF_LE(al_entry->mft_reference) ==
+ base_ni->mft_no) {
+ ni = ctx->ntfs_ino = base_ni;
+ ctx->mrec = ctx->base_mrec;
+ } else {
+ /* We want an extent record. */
+ ctx->mrec = map_extent_mft_record(base_ni,
+ le64_to_cpu(
+ al_entry->mft_reference), &ni);
+ if (IS_ERR(ctx->mrec)) {
+ ntfs_error(vol->sb, "Failed to map "
+ "extent mft record "
+ "0x%lx of base inode "
+ "0x%lx.%s",
+ MREF_LE(al_entry->
+ mft_reference),
+ base_ni->mft_no, es);
+ err = PTR_ERR(ctx->mrec);
+ if (err == -ENOENT)
+ err = -EIO;
+ /* Cause @ctx to be sanitized below. */
+ ni = NULL;
+ break;
+ }
+ ctx->ntfs_ino = ni;
+ }
+ ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
+ le16_to_cpu(ctx->mrec->attrs_offset));
+ }
+ /*
+ * ctx->vfs_ino, ctx->mrec, and ctx->attr now point to the
+ * mft record containing the attribute represented by the
+ * current al_entry.
+ */
+ /*
+ * We could call into ntfs_attr_find() to find the right
+ * attribute in this mft record but this would be less
+ * efficient and not quite accurate as ntfs_attr_find() ignores
+ * the attribute instance numbers for example which become
+ * important when one plays with attribute lists. Also,
+ * because a proper match has been found in the attribute list
+ * entry above, the comparison can now be optimized. So it is
+ * worth re-implementing a simplified ntfs_attr_find() here.
+ */
+ a = ctx->attr;
+ /*
+ * Use a manual loop so we can still use break and continue
+ * with the same meanings as above.
+ */
+do_next_attr_loop:
+ if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec +
+ le32_to_cpu(ctx->mrec->bytes_allocated))
+ break;
+ if (a->type == AT_END)
+ break;
+ if (!a->length)
+ break;
+ if (al_entry->instance != a->instance)
+ goto do_next_attr;
+ /*
+ * If the type and/or the name are mismatched between the
+ * attribute list entry and the attribute record, there is
+ * corruption so we break and return error EIO.
+ */
+ if (al_entry->type != a->type)
+ break;
+ if (!ntfs_are_names_equal((ntfschar*)((u8*)a +
+ le16_to_cpu(a->name_offset)), a->name_length,
+ al_name, al_name_len, CASE_SENSITIVE,
+ vol->upcase, vol->upcase_len))
+ break;
+ ctx->attr = a;
+ /*
+ * If no @val specified or @val specified and it matches, we
+ * have found it!
+ */
+ if (!val || (!a->non_resident && le32_to_cpu(
+ a->data.resident.value_length) == val_len &&
+ !memcmp((u8*)a +
+ le16_to_cpu(a->data.resident.value_offset),
+ val, val_len))) {
+ ntfs_debug("Done, found.");
+ return 0;
+ }
+do_next_attr:
+ /* Proceed to the next attribute in the current mft record. */
+ a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length));
+ goto do_next_attr_loop;
+ }
+ if (!err) {
+ ntfs_error(vol->sb, "Base inode 0x%lx contains corrupt "
+ "attribute list attribute.%s", base_ni->mft_no,
+ es);
+ err = -EIO;
+ }
+ if (ni != base_ni) {
+ if (ni)
+ unmap_extent_mft_record(ni);
+ ctx->ntfs_ino = base_ni;
+ ctx->mrec = ctx->base_mrec;
+ ctx->attr = ctx->base_attr;
+ }
+ if (err != -ENOMEM)
+ NVolSetErrors(vol);
+ return err;
+not_found:
+ /*
+ * If we were looking for AT_END, we reset the search context @ctx and
+ * use ntfs_attr_find() to seek to the end of the base mft record.
+ */
+ if (type == AT_END) {
+ ntfs_attr_reinit_search_ctx(ctx);
+ return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len,
+ ctx);
+ }
+ /*
+ * The attribute was not found. Before we return, we want to ensure
+ * @ctx->mrec and @ctx->attr indicate the position at which the
+ * attribute should be inserted in the base mft record. Since we also
+ * want to preserve @ctx->al_entry we cannot reinitialize the search
+ * context using ntfs_attr_reinit_search_ctx() as this would set
+ * @ctx->al_entry to NULL. Thus we do the necessary bits manually (see
+ * ntfs_attr_init_search_ctx() below). Note, we _only_ preserve
+ * @ctx->al_entry as the remaining fields (base_*) are identical to
+ * their non base_ counterparts and we cannot set @ctx->base_attr
+ * correctly yet as we do not know what @ctx->attr will be set to by
+ * the call to ntfs_attr_find() below.
+ */
+ if (ni != base_ni)
+ unmap_extent_mft_record(ni);
+ ctx->mrec = ctx->base_mrec;
+ ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
+ le16_to_cpu(ctx->mrec->attrs_offset));
+ ctx->is_first = true;
+ ctx->ntfs_ino = base_ni;
+ ctx->base_ntfs_ino = NULL;
+ ctx->base_mrec = NULL;
+ ctx->base_attr = NULL;
+ /*
+ * In case there are multiple matches in the base mft record, need to
+ * keep enumerating until we get an attribute not found response (or
+ * another error), otherwise we would keep returning the same attribute
+ * over and over again and all programs using us for enumeration would
+ * lock up in a tight loop.
+ */
+ do {
+ err = ntfs_attr_find(type, name, name_len, ic, val, val_len,
+ ctx);
+ } while (!err);
+ ntfs_debug("Done, not found.");
+ return err;
+}
+
+/**
+ * ntfs_attr_lookup - find an attribute in an ntfs inode
+ * @type: attribute type to find
+ * @name: attribute name to find (optional, i.e. NULL means don't care)
+ * @name_len: attribute name length (only needed if @name present)
+ * @ic: IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
+ * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only)
+ * @val: attribute value to find (optional, resident attributes only)
+ * @val_len: attribute value length
+ * @ctx: search context with mft record and attribute to search from
+ *
+ * Find an attribute in an ntfs inode. On first search @ctx->ntfs_ino must
+ * be the base mft record and @ctx must have been obtained from a call to
+ * ntfs_attr_get_search_ctx().
+ *
+ * This function transparently handles attribute lists and @ctx is used to
+ * continue searches where they were left off at.
+ *
+ * After finishing with the attribute/mft record you need to call
+ * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
+ * mapped inodes, etc).
+ *
+ * Return 0 if the search was successful and -errno if not.
+ *
+ * When 0, @ctx->attr is the found attribute and it is in mft record
+ * @ctx->mrec. If an attribute list attribute is present, @ctx->al_entry is
+ * the attribute list entry of the found attribute.
+ *
+ * When -ENOENT, @ctx->attr is the attribute which collates just after the
+ * attribute being searched for, i.e. if one wants to add the attribute to the
+ * mft record this is the correct place to insert it into. If an attribute
+ * list attribute is present, @ctx->al_entry is the attribute list entry which
+ * collates just after the attribute list entry of the attribute being searched
+ * for, i.e. if one wants to add the attribute to the mft record this is the
+ * correct place to insert its attribute list entry into.
+ *
+ * When -errno != -ENOENT, an error occurred during the lookup. @ctx->attr is
+ * then undefined and in particular you should not rely on it not changing.
+ */
+int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
+ const u32 name_len, const IGNORE_CASE_BOOL ic,
+ const VCN lowest_vcn, const u8 *val, const u32 val_len,
+ ntfs_attr_search_ctx *ctx)
+{
+ ntfs_inode *base_ni;
+
+ ntfs_debug("Entering.");
+ BUG_ON(IS_ERR(ctx->mrec));
+ if (ctx->base_ntfs_ino)
+ base_ni = ctx->base_ntfs_ino;
+ else
+ base_ni = ctx->ntfs_ino;
+ /* Sanity check, just for debugging really. */
+ BUG_ON(!base_ni);
+ if (!NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST)
+ return ntfs_attr_find(type, name, name_len, ic, val, val_len,
+ ctx);
+ return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn,
+ val, val_len, ctx);
+}
+
+/**
+ * ntfs_attr_init_search_ctx - initialize an attribute search context
+ * @ctx: attribute search context to initialize
+ * @ni: ntfs inode with which to initialize the search context
+ * @mrec: mft record with which to initialize the search context
+ *
+ * Initialize the attribute search context @ctx with @ni and @mrec.
+ */
+static inline void ntfs_attr_init_search_ctx(ntfs_attr_search_ctx *ctx,
+ ntfs_inode *ni, MFT_RECORD *mrec)
+{
+ *ctx = (ntfs_attr_search_ctx) {
+ .mrec = mrec,
+ /* Sanity checks are performed elsewhere. */
+ .attr = (ATTR_RECORD*)((u8*)mrec +
+ le16_to_cpu(mrec->attrs_offset)),
+ .is_first = true,
+ .ntfs_ino = ni,
+ };
+}
+
+/**
+ * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context
+ * @ctx: attribute search context to reinitialize
+ *
+ * Reinitialize the attribute search context @ctx, unmapping an associated
+ * extent mft record if present, and initialize the search context again.
+ *
+ * This is used when a search for a new attribute is being started to reset
+ * the search context to the beginning.
+ */
+void ntfs_attr_reinit_search_ctx(ntfs_attr_search_ctx *ctx)
+{
+ if (likely(!ctx->base_ntfs_ino)) {
+ /* No attribute list. */
+ ctx->is_first = true;
+ /* Sanity checks are performed elsewhere. */
+ ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
+ le16_to_cpu(ctx->mrec->attrs_offset));
+ /*
+ * This needs resetting due to ntfs_external_attr_find() which
+ * can leave it set despite having zeroed ctx->base_ntfs_ino.
+ */
+ ctx->al_entry = NULL;
+ return;
+ } /* Attribute list. */
+ if (ctx->ntfs_ino != ctx->base_ntfs_ino)
+ unmap_extent_mft_record(ctx->ntfs_ino);
+ ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec);
+ return;
+}
+
+/**
+ * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context
+ * @ni: ntfs inode with which to initialize the search context
+ * @mrec: mft record with which to initialize the search context
+ *
+ * Allocate a new attribute search context, initialize it with @ni and @mrec,
+ * and return it. Return NULL if allocation failed.
+ */
+ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec)
+{
+ ntfs_attr_search_ctx *ctx;
+
+ ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, GFP_NOFS);
+ if (ctx)
+ ntfs_attr_init_search_ctx(ctx, ni, mrec);
+ return ctx;
+}
+
+/**
+ * ntfs_attr_put_search_ctx - release an attribute search context
+ * @ctx: attribute search context to free
+ *
+ * Release the attribute search context @ctx, unmapping an associated extent
+ * mft record if present.
+ */
+void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx)
+{
+ if (ctx->base_ntfs_ino && ctx->ntfs_ino != ctx->base_ntfs_ino)
+ unmap_extent_mft_record(ctx->ntfs_ino);
+ kmem_cache_free(ntfs_attr_ctx_cache, ctx);
+ return;
+}
+
+#ifdef NTFS_RW
+
+/**
+ * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to find
+ *
+ * Search for the attribute definition record corresponding to the attribute
+ * @type in the $AttrDef system file.
+ *
+ * Return the attribute type definition record if found and NULL if not found.
+ */
+static ATTR_DEF *ntfs_attr_find_in_attrdef(const ntfs_volume *vol,
+ const ATTR_TYPE type)
+{
+ ATTR_DEF *ad;
+
+ BUG_ON(!vol->attrdef);
+ BUG_ON(!type);
+ for (ad = vol->attrdef; (u8*)ad - (u8*)vol->attrdef <
+ vol->attrdef_size && ad->type; ++ad) {
+ /* We have not found it yet, carry on searching. */
+ if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type)))
+ continue;
+ /* We found the attribute; return it. */
+ if (likely(ad->type == type))
+ return ad;
+ /* We have gone too far already. No point in continuing. */
+ break;
+ }
+ /* Attribute not found. */
+ ntfs_debug("Attribute type 0x%x not found in $AttrDef.",
+ le32_to_cpu(type));
+ return NULL;
+}
+
+/**
+ * ntfs_attr_size_bounds_check - check a size of an attribute type for validity
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to check
+ * @size: size which to check
+ *
+ * Check whether the @size in bytes is valid for an attribute of @type on the
+ * ntfs volume @vol. This information is obtained from $AttrDef system file.
+ *
+ * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not
+ * listed in $AttrDef.
+ */
+int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPE type,
+ const s64 size)
+{
+ ATTR_DEF *ad;
+
+ BUG_ON(size < 0);
+ /*
+ * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not
+ * listed in $AttrDef.
+ */
+ if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024))
+ return -ERANGE;
+ /* Get the $AttrDef entry for the attribute @type. */
+ ad = ntfs_attr_find_in_attrdef(vol, type);
+ if (unlikely(!ad))
+ return -ENOENT;
+ /* Do the bounds check. */
+ if (((sle64_to_cpu(ad->min_size) > 0) &&
+ size < sle64_to_cpu(ad->min_size)) ||
+ ((sle64_to_cpu(ad->max_size) > 0) && size >
+ sle64_to_cpu(ad->max_size)))
+ return -ERANGE;
+ return 0;
+}
+
+/**
+ * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to check
+ *
+ * Check whether the attribute of @type on the ntfs volume @vol is allowed to
+ * be non-resident. This information is obtained from $AttrDef system file.
+ *
+ * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, and
+ * -ENOENT if the attribute is not listed in $AttrDef.
+ */
+int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type)
+{
+ ATTR_DEF *ad;
+
+ /* Find the attribute definition record in $AttrDef. */
+ ad = ntfs_attr_find_in_attrdef(vol, type);
+ if (unlikely(!ad))
+ return -ENOENT;
+ /* Check the flags and return the result. */
+ if (ad->flags & ATTR_DEF_RESIDENT)
+ return -EPERM;
+ return 0;
+}
+
+/**
+ * ntfs_attr_can_be_resident - check if an attribute can be resident
+ * @vol: ntfs volume to which the attribute belongs
+ * @type: attribute type which to check
+ *
+ * Check whether the attribute of @type on the ntfs volume @vol is allowed to
+ * be resident. This information is derived from our ntfs knowledge and may
+ * not be completely accurate, especially when user defined attributes are
+ * present. Basically we allow everything to be resident except for index
+ * allocation and $EA attributes.
+ *
+ * Return 0 if the attribute is allowed to be non-resident and -EPERM if not.
+ *
+ * Warning: In the system file $MFT the attribute $Bitmap must be non-resident
+ * otherwise windows will not boot (blue screen of death)! We cannot
+ * check for this here as we do not know which inode's $Bitmap is
+ * being asked about so the caller needs to special case this.
+ */
+int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type)
+{
+ if (type == AT_INDEX_ALLOCATION)
+ return -EPERM;
+ return 0;
+}
+
+/**
+ * ntfs_attr_record_resize - resize an attribute record
+ * @m: mft record containing attribute record
+ * @a: attribute record to resize
+ * @new_size: new size in bytes to which to resize the attribute record @a
+ *
+ * Resize the attribute record @a, i.e. the resident part of the attribute, in
+ * the mft record @m to @new_size bytes.
+ *
+ * Return 0 on success and -errno on error. The following error codes are
+ * defined:
+ * -ENOSPC - Not enough space in the mft record @m to perform the resize.
+ *
+ * Note: On error, no modifications have been performed whatsoever.
+ *
+ * Warning: If you make a record smaller without having copied all the data you
+ * are interested in the data may be overwritten.
+ */
+int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
+{
+ ntfs_debug("Entering for new_size %u.", new_size);
+ /* Align to 8 bytes if it is not already done. */
+ if (new_size & 7)
+ new_size = (new_size + 7) & ~7;
+ /* If the actual attribute length has changed, move things around. */
+ if (new_size != le32_to_cpu(a->length)) {
+ u32 new_muse = le32_to_cpu(m->bytes_in_use) -
+ le32_to_cpu(a->length) + new_size;
+ /* Not enough space in this mft record. */
+ if (new_muse > le32_to_cpu(m->bytes_allocated))
+ return -ENOSPC;
+ /* Move attributes following @a to their new location. */
+ memmove((u8*)a + new_size, (u8*)a + le32_to_cpu(a->length),
+ le32_to_cpu(m->bytes_in_use) - ((u8*)a -
+ (u8*)m) - le32_to_cpu(a->length));
+ /* Adjust @m to reflect the change in used space. */
+ m->bytes_in_use = cpu_to_le32(new_muse);
+ /* Adjust @a to reflect the new size. */
+ if (new_size >= offsetof(ATTR_REC, length) + sizeof(a->length))
+ a->length = cpu_to_le32(new_size);
+ }
+ return 0;
+}
+
+/**
+ * ntfs_resident_attr_value_resize - resize the value of a resident attribute
+ * @m: mft record containing attribute record
+ * @a: attribute record whose value to resize
+ * @new_size: new size in bytes to which to resize the attribute value of @a
+ *
+ * Resize the value of the attribute @a in the mft record @m to @new_size bytes.
+ * If the value is made bigger, the newly allocated space is cleared.
+ *
+ * Return 0 on success and -errno on error. The following error codes are
+ * defined:
+ * -ENOSPC - Not enough space in the mft record @m to perform the resize.
+ *
+ * Note: On error, no modifications have been performed whatsoever.
+ *
+ * Warning: If you make a record smaller without having copied all the data you
+ * are interested in the data may be overwritten.
+ */
+int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
+ const u32 new_size)
+{
+ u32 old_size;
+
+ /* Resize the resident part of the attribute record. */
+ if (ntfs_attr_record_resize(m, a,
+ le16_to_cpu(a->data.resident.value_offset) + new_size))
+ return -ENOSPC;
+ /*
+ * The resize succeeded! If we made the attribute value bigger, clear
+ * the area between the old size and @new_size.
+ */
+ old_size = le32_to_cpu(a->data.resident.value_length);
+ if (new_size > old_size)
+ memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
+ old_size, 0, new_size - old_size);
+ /* Finally update the length of the attribute value. */
+ a->data.resident.value_length = cpu_to_le32(new_size);
+ return 0;
+}
+
+/**
+ * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
+ * @ni: ntfs inode describing the attribute to convert
+ * @data_size: size of the resident data to copy to the non-resident attribute
+ *
+ * Convert the resident ntfs attribute described by the ntfs inode @ni to a
+ * non-resident one.
+ *
+ * @data_size must be equal to the attribute value size. This is needed since
+ * we need to know the size before we can map the mft record and our callers
+ * always know it. The reason we cannot simply read the size from the vfs
+ * inode i_size is that this is not necessarily uptodate. This happens when
+ * ntfs_attr_make_non_resident() is called in the ->truncate call path(s).
+ *
+ * Return 0 on success and -errno on error. The following error return codes
+ * are defined:
+ * -EPERM - The attribute is not allowed to be non-resident.
+ * -ENOMEM - Not enough memory.
+ * -ENOSPC - Not enough disk space.
+ * -EINVAL - Attribute not defined on the volume.
+ * -EIO - I/o error or other error.
+ * Note that -ENOSPC is also returned in the case that there is not enough
+ * space in the mft record to do the conversion. This can happen when the mft
+ * record is already very full. The caller is responsible for trying to make
+ * space in the mft record and trying again. FIXME: Do we need a separate
+ * error return code for this kind of -ENOSPC or is it always worth trying
+ * again in case the attribute may then fit in a resident state so no need to
+ * make it non-resident at all? Ho-hum... (AIA)
+ *
+ * NOTE to self: No changes in the attribute list are required to move from
+ * a resident to a non-resident attribute.
+ *
+ * Locking: - The caller must hold i_mutex on the inode.
+ */
+int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
+{
+ s64 new_size;
+ struct inode *vi = VFS_I(ni);
+ ntfs_volume *vol = ni->vol;
+ ntfs_inode *base_ni;
+ MFT_RECORD *m;
+ ATTR_RECORD *a;
+ ntfs_attr_search_ctx *ctx;
+ struct page *page;
+ runlist_element *rl;
+ u8 *kaddr;
+ unsigned long flags;
+ int mp_size, mp_ofs, name_ofs, arec_size, err, err2;
+ u32 attr_size;
+ u8 old_res_attr_flags;
+
+ /* Check that the attribute is allowed to be non-resident. */
+ err = ntfs_attr_can_be_non_resident(vol, ni->type);
+ if (unlikely(err)) {
+ if (err == -EPERM)
+ ntfs_debug("Attribute is not allowed to be "
+ "non-resident.");
+ else
+ ntfs_debug("Attribute not defined on the NTFS "
+ "volume!");
+ return err;
+ }
+ /*
+ * FIXME: Compressed and encrypted attributes are not supported when
+ * writing and we should never have gotten here for them.
+ */
+ BUG_ON(NInoCompressed(ni));
+ BUG_ON(NInoEncrypted(ni));
+ /*
+ * The size needs to be aligned to a cluster boundary for allocation
+ * purposes.
+ */
+ new_size = (data_size + vol->cluster_size - 1) &
+ ~(vol->cluster_size - 1);
+ if (new_size > 0) {
+ /*
+ * Will need the page later and since the page lock nests
+ * outside all ntfs locks, we need to get the page now.
+ */
+ page = find_or_create_page(vi->i_mapping, 0,
+ mapping_gfp_mask(vi->i_mapping));
+ if (unlikely(!page))
+ return -ENOMEM;
+ /* Start by allocating clusters to hold the attribute value. */
+ rl = ntfs_cluster_alloc(vol, 0, new_size >>
+ vol->cluster_size_bits, -1, DATA_ZONE, true);
+ if (IS_ERR(rl)) {
+ err = PTR_ERR(rl);
+ ntfs_debug("Failed to allocate cluster%s, error code "
+ "%i.", (new_size >>
+ vol->cluster_size_bits) > 1 ? "s" : "",
+ err);
+ goto page_err_out;
+ }
+ } else {
+ rl = NULL;
+ page = NULL;
+ }
+ /* Determine the size of the mapping pairs array. */
+ mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0, -1);
+ if (unlikely(mp_size < 0)) {
+ err = mp_size;
+ ntfs_debug("Failed to get size for mapping pairs array, error "
+ "code %i.", err);
+ goto rl_err_out;
+ }
+ 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);
+ m = NULL;
+ ctx = NULL;
+ goto err_out;
+ }
+ ctx = ntfs_attr_get_search_ctx(base_ni, m);
+ if (unlikely(!ctx)) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, 0, NULL, 0, ctx);
+ if (unlikely(err)) {
+ if (err == -ENOENT)
+ err = -EIO;
+ goto err_out;
+ }
+ m = ctx->mrec;
+ a = ctx->attr;
+ BUG_ON(NInoNonResident(ni));
+ BUG_ON(a->non_resident);
+ /*
+ * Calculate new offsets for the name and the mapping pairs array.
+ */
+ if (NInoSparse(ni) || NInoCompressed(ni))
+ name_ofs = (offsetof(ATTR_REC,
+ data.non_resident.compressed_size) +
+ sizeof(a->data.non_resident.compressed_size) +
+ 7) & ~7;
+ else
+ name_ofs = (offsetof(ATTR_REC,
+ data.non_resident.compressed_size) + 7) & ~7;
+ mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
+ /*
+ * Determine the size of the resident part of the now non-resident
+ * attribute record.
+ */
+ arec_size = (mp_ofs + mp_size + 7) & ~7;
+ /*
+ * If the page is not uptodate bring it uptodate by copying from the
+ * attribute value.
+ */
+ attr_size = le32_to_cpu(a->data.resident.value_length);
+ BUG_ON(attr_size != data_size);
+ if (page && !PageUptodate(page)) {
+ kaddr = kmap_atomic(page);
+ memcpy(kaddr, (u8*)a +
+ le16_to_cpu(a->data.resident.value_offset),
+ attr_size);
+ memset(kaddr + attr_size, 0, PAGE_CACHE_SIZE - attr_size);
+ kunmap_atomic(kaddr);
+ flush_dcache_page(page);
+ SetPageUptodate(page);
+ }
+ /* Backup the attribute flag. */
+ old_res_attr_flags = a->data.resident.flags;
+ /* Resize the resident part of the attribute record. */
+ err = ntfs_attr_record_resize(m, a, arec_size);
+ if (unlikely(err))
+ goto err_out;
+ /*
+ * Convert the resident part of the attribute record to describe a
+ * non-resident attribute.
+ */
+ a->non_resident = 1;
+ /* Move the attribute name if it exists and update the offset. */
+ if (a->name_length)
+ memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
+ a->name_length * sizeof(ntfschar));
+ a->name_offset = cpu_to_le16(name_ofs);
+ /* Setup the fields specific to non-resident attributes. */
+ a->data.non_resident.lowest_vcn = 0;
+ a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >>
+ vol->cluster_size_bits);
+ a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
+ memset(&a->data.non_resident.reserved, 0,
+ sizeof(a->data.non_resident.reserved));
+ a->data.non_resident.allocated_size = cpu_to_sle64(new_size);
+ a->data.non_resident.data_size =
+ a->data.non_resident.initialized_size =
+ cpu_to_sle64(attr_size);
+ if (NInoSparse(ni) || NInoCompressed(ni)) {
+ a->data.non_resident.compression_unit = 0;
+ if (NInoCompressed(ni) || vol->major_ver < 3)
+ a->data.non_resident.compression_unit = 4;
+ a->data.non_resident.compressed_size =
+ a->data.non_resident.allocated_size;
+ } else
+ a->data.non_resident.compression_unit = 0;
+ /* Generate the mapping pairs array into the attribute record. */
+ err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
+ arec_size - mp_ofs, rl, 0, -1, NULL);
+ if (unlikely(err)) {
+ ntfs_debug("Failed to build mapping pairs, error code %i.",
+ err);
+ goto undo_err_out;
+ }
+ /* Setup the in-memory attribute structure to be non-resident. */
+ ni->runlist.rl = rl;
+ write_lock_irqsave(&ni->size_lock, flags);
+ ni->allocated_size = new_size;
+ if (NInoSparse(ni) || NInoCompressed(ni)) {
+ ni->itype.compressed.size = ni->allocated_size;
+ if (a->data.non_resident.compression_unit) {
+ ni->itype.compressed.block_size = 1U << (a->data.
+ non_resident.compression_unit +
+ vol->cluster_size_bits);
+ ni->itype.compressed.block_size_bits =
+ ffs(ni->itype.compressed.block_size) -
+ 1;
+ ni->itype.compressed.block_clusters = 1U <<
+ a->data.non_resident.compression_unit;
+ } else {
+ ni->itype.compressed.block_size = 0;
+ ni->itype.compressed.block_size_bits = 0;
+ ni->itype.compressed.block_clusters = 0;
+ }
+ vi->i_blocks = ni->itype.compressed.size >> 9;
+ } else
+ vi->i_blocks = ni->allocated_size >> 9;
+ write_unlock_irqrestore(&ni->size_lock, flags);
+ /*
+ * This needs to be last since the address space operations ->readpage
+ * and ->writepage can run concurrently with us as they are not
+ * serialized on i_mutex. Note, we are not allowed to fail once we flip
+ * this switch, which is another reason to do this last.
+ */
+ NInoSetNonResident(ni);
+ /* Mark the mft record dirty, so it gets written back. */
+ flush_dcache_mft_record_page(ctx->ntfs_ino);
+ mark_mft_record_dirty(ctx->ntfs_ino);
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(base_ni);
+ up_write(&ni->runlist.lock);
+ if (page) {
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ ntfs_debug("Done.");
+ return 0;
+undo_err_out:
+ /* Convert the attribute back into a resident attribute. */
+ a->non_resident = 0;
+ /* Move the attribute name if it exists and update the offset. */
+ name_ofs = (offsetof(ATTR_RECORD, data.resident.reserved) +
+ sizeof(a->data.resident.reserved) + 7) & ~7;
+ if (a->name_length)
+ memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
+ a->name_length * sizeof(ntfschar));
+ mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
+ a->name_offset = cpu_to_le16(name_ofs);
+ arec_size = (mp_ofs + attr_size + 7) & ~7;
+ /* Resize the resident part of the attribute record. */
+ err2 = ntfs_attr_record_resize(m, a, arec_size);
+ if (unlikely(err2)) {
+ /*
+ * This cannot happen (well if memory corruption is at work it
+ * could happen in theory), but deal with it as well as we can.
+ * If the old size is too small, truncate the attribute,
+ * otherwise simply give it a larger allocated size.
+ * FIXME: Should check whether chkdsk complains when the
+ * allocated size is much bigger than the resident value size.
+ */
+ arec_size = le32_to_cpu(a->length);
+ if ((mp_ofs + attr_size) > arec_size) {
+ err2 = attr_size;
+ attr_size = arec_size - mp_ofs;
+ ntfs_error(vol->sb, "Failed to undo partial resident "
+ "to non-resident attribute "
+ "conversion. Truncating inode 0x%lx, "
+ "attribute type 0x%x from %i bytes to "
+ "%i bytes to maintain metadata "
+ "consistency. THIS MEANS YOU ARE "
+ "LOSING %i BYTES DATA FROM THIS %s.",
+ vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type),
+ err2, attr_size, err2 - attr_size,
+ ((ni->type == AT_DATA) &&
+ !ni->name_len) ? "FILE": "ATTRIBUTE");
+ write_lock_irqsave(&ni->size_lock, flags);
+ ni->initialized_size = attr_size;
+ i_size_write(vi, attr_size);
+ write_unlock_irqrestore(&ni->size_lock, flags);
+ }
+ }
+ /* Setup the fields specific to resident attributes. */
+ a->data.resident.value_length = cpu_to_le32(attr_size);
+ a->data.resident.value_offset = cpu_to_le16(mp_ofs);
+ a->data.resident.flags = old_res_attr_flags;
+ memset(&a->data.resident.reserved, 0,
+ sizeof(a->data.resident.reserved));
+ /* Copy the data from the page back to the attribute value. */
+ if (page) {
+ kaddr = kmap_atomic(page);
+ memcpy((u8*)a + mp_ofs, kaddr, attr_size);
+ kunmap_atomic(kaddr);
+ }
+ /* Setup the allocated size in the ntfs inode in case it changed. */
+ write_lock_irqsave(&ni->size_lock, flags);
+ ni->allocated_size = arec_size - mp_ofs;
+ write_unlock_irqrestore(&ni->size_lock, flags);
+ /* Mark the mft record dirty, so it gets written back. */
+ flush_dcache_mft_record_page(ctx->ntfs_ino);
+ mark_mft_record_dirty(ctx->ntfs_ino);
+err_out:
+ if (ctx)
+ ntfs_attr_put_search_ctx(ctx);
+ if (m)
+ unmap_mft_record(base_ni);
+ ni->runlist.rl = NULL;
+ up_write(&ni->runlist.lock);
+rl_err_out:
+ if (rl) {
+ if (ntfs_cluster_free_from_rl(vol, rl) < 0) {
+ ntfs_error(vol->sb, "Failed to release allocated "
+ "cluster(s) in error code path. Run "
+ "chkdsk to recover the lost "
+ "cluster(s).");
+ NVolSetErrors(vol);
+ }
+ ntfs_free(rl);
+page_err_out:
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ if (err == -EINVAL)
+ err = -EIO;
+ return err;
+}
+
+/**
+ * ntfs_attr_extend_allocation - extend the allocated space of an attribute
+ * @ni: ntfs inode of the attribute whose allocation to extend
+ * @new_alloc_size: new size in bytes to which to extend the allocation to
+ * @new_data_size: new size in bytes to which to extend the data to
+ * @data_start: beginning of region which is required to be non-sparse
+ *
+ * Extend the allocated space of an attribute described by the ntfs inode @ni
+ * to @new_alloc_size bytes. If @data_start is -1, the whole extension may be
+ * implemented as a hole in the file (as long as both the volume and the ntfs
+ * inode @ni have sparse support enabled). If @data_start is >= 0, then the
+ * region between the old allocated size and @data_start - 1 may be made sparse
+ * but the regions between @data_start and @new_alloc_size must be backed by
+ * actual clusters.
+ *
+ * If @new_data_size is -1, it is ignored. If it is >= 0, then the data size
+ * of the attribute is extended to @new_data_size. Note that the i_size of the
+ * vfs inode is not updated. Only the data size in the base attribute record
+ * is updated. The caller has to update i_size separately if this is required.
+ * WARNING: It is a BUG() for @new_data_size to be smaller than the old data
+ * size as well as for @new_data_size to be greater than @new_alloc_size.
+ *
+ * For resident attributes this involves resizing the attribute record and if
+ * necessary moving it and/or other attributes into extent mft records and/or
+ * converting the attribute to a non-resident attribute which in turn involves
+ * extending the allocation of a non-resident attribute as described below.
+ *
+ * For non-resident attributes this involves allocating clusters in the data
+ * zone on the volume (except for regions that are being made sparse) and
+ * extending the run list to describe the allocated clusters as well as
+ * updating the mapping pairs array of the attribute. This in turn involves
+ * resizing the attribute record and if necessary moving it and/or other
+ * attributes into extent mft records and/or splitting the attribute record
+ * into multiple extent attribute records.
+ *
+ * Also, the attribute list attribute is updated if present and in some of the
+ * above cases (the ones where extent mft records/attributes come into play),
+ * an attribute list attribute is created if not already present.
+ *
+ * Return the new allocated size on success and -errno on error. In the case
+ * that an error is encountered but a partial extension at least up to
+ * @data_start (if present) is possible, the allocation is partially extended
+ * and this is returned. This means the caller must check the returned size to
+ * determine if the extension was partial. If @data_start is -1 then partial
+ * allocations are not performed.
+ *
+ * WARNING: Do not call ntfs_attr_extend_allocation() for $MFT/$DATA.
+ *
+ * Locking: This function takes the runlist lock of @ni for writing as well as
+ * locking the mft record of the base ntfs inode. These locks are maintained
+ * throughout execution of the function. These locks are required so that the
+ * attribute can be resized safely and so that it can for example be converted
+ * from resident to non-resident safely.
+ *
+ * TODO: At present attribute list attribute handling is not implemented.
+ *
+ * TODO: At present it is not safe to call this function for anything other
+ * than the $DATA attribute(s) of an uncompressed and unencrypted file.
+ */
+s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
+ const s64 new_data_size, const s64 data_start)
+{
+ VCN vcn;
+ s64 ll, allocated_size, start = data_start;
+ struct inode *vi = VFS_I(ni);
+ ntfs_volume *vol = ni->vol;
+ ntfs_inode *base_ni;
+ MFT_RECORD *m;
+ ATTR_RECORD *a;
+ ntfs_attr_search_ctx *ctx;
+ runlist_element *rl, *rl2;
+ unsigned long flags;
+ int err, mp_size;
+ u32 attr_len = 0; /* Silence stupid gcc warning. */
+ bool mp_rebuilt;
+
+#ifdef DEBUG
+ read_lock_irqsave(&ni->size_lock, flags);
+ allocated_size = ni->allocated_size;
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
+ "old_allocated_size 0x%llx, "
+ "new_allocated_size 0x%llx, new_data_size 0x%llx, "
+ "data_start 0x%llx.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type),
+ (unsigned long long)allocated_size,
+ (unsigned long long)new_alloc_size,
+ (unsigned long long)new_data_size,
+ (unsigned long long)start);
+#endif
+retry_extend:
+ /*
+ * For non-resident attributes, @start and @new_size need to be aligned
+ * to cluster boundaries for allocation purposes.
+ */
+ if (NInoNonResident(ni)) {
+ if (start > 0)
+ start &= ~(s64)vol->cluster_size_mask;
+ new_alloc_size = (new_alloc_size + vol->cluster_size - 1) &
+ ~(s64)vol->cluster_size_mask;
+ }
+ BUG_ON(new_data_size >= 0 && new_data_size > new_alloc_size);
+ /* Check if new size is allowed in $AttrDef. */
+ err = ntfs_attr_size_bounds_check(vol, ni->type, new_alloc_size);
+ if (unlikely(err)) {
+ /* Only emit errors when the write will fail completely. */
+ read_lock_irqsave(&ni->size_lock, flags);
+ allocated_size = ni->allocated_size;
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (start < 0 || start >= allocated_size) {
+ if (err == -ERANGE) {
+ ntfs_error(vol->sb, "Cannot extend allocation "
+ "of inode 0x%lx, attribute "
+ "type 0x%x, because the new "
+ "allocation would exceed the "
+ "maximum allowed size for "
+ "this attribute type.",
+ vi->i_ino, (unsigned)
+ le32_to_cpu(ni->type));
+ } else {
+ ntfs_error(vol->sb, "Cannot extend allocation "
+ "of inode 0x%lx, attribute "
+ "type 0x%x, because this "
+ "attribute type is not "
+ "defined on the NTFS volume. "
+ "Possible corruption! You "
+ "should run chkdsk!",
+ vi->i_ino, (unsigned)
+ le32_to_cpu(ni->type));
+ }
+ }
+ /* Translate error code to be POSIX conformant for write(2). */
+ if (err == -ERANGE)
+ err = -EFBIG;
+ else
+ err = -EIO;
+ return err;
+ }
+ if (!NInoAttr(ni))
+ base_ni = ni;
+ else
+ base_ni = ni->ext.base_ntfs_ino;
+ /*
+ * We will be modifying both the runlist (if non-resident) and the mft
+ * record so lock them both down.
+ */
+ down_write(&ni->runlist.lock);
+ m = map_mft_record(base_ni);
+ if (IS_ERR(m)) {
+ err = PTR_ERR(m);
+ m = NULL;
+ ctx = NULL;
+ goto err_out;
+ }
+ ctx = ntfs_attr_get_search_ctx(base_ni, m);
+ if (unlikely(!ctx)) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ read_lock_irqsave(&ni->size_lock, flags);
+ allocated_size = ni->allocated_size;
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ /*
+ * If non-resident, seek to the last extent. If resident, there is
+ * only one extent, so seek to that.
+ */
+ vcn = NInoNonResident(ni) ? allocated_size >> vol->cluster_size_bits :
+ 0;
+ /*
+ * Abort if someone did the work whilst we waited for the locks. If we
+ * just converted the attribute from resident to non-resident it is
+ * likely that exactly this has happened already. We cannot quite
+ * abort if we need to update the data size.
+ */
+ if (unlikely(new_alloc_size <= allocated_size)) {
+ ntfs_debug("Allocated size already exceeds requested size.");
+ new_alloc_size = allocated_size;
+ if (new_data_size < 0)
+ goto done;
+ /*
+ * We want the first attribute extent so that we can update the
+ * data size.
+ */
+ vcn = 0;
+ }
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, vcn, NULL, 0, ctx);
+ if (unlikely(err)) {
+ if (err == -ENOENT)
+ err = -EIO;
+ goto err_out;
+ }
+ m = ctx->mrec;
+ a = ctx->attr;
+ /* Use goto to reduce indentation. */
+ if (a->non_resident)
+ goto do_non_resident_extend;
+ BUG_ON(NInoNonResident(ni));
+ /* The total length of the attribute value. */
+ attr_len = le32_to_cpu(a->data.resident.value_length);
+ /*
+ * Extend the attribute record to be able to store the new attribute
+ * size. ntfs_attr_record_resize() will not do anything if the size is
+ * not changing.
+ */
+ if (new_alloc_size < vol->mft_record_size &&
+ !ntfs_attr_record_resize(m, a,
+ le16_to_cpu(a->data.resident.value_offset) +
+ new_alloc_size)) {
+ /* The resize succeeded! */
+ write_lock_irqsave(&ni->size_lock, flags);
+ ni->allocated_size = le32_to_cpu(a->length) -
+ le16_to_cpu(a->data.resident.value_offset);
+ write_unlock_irqrestore(&ni->size_lock, flags);
+ if (new_data_size >= 0) {
+ BUG_ON(new_data_size < attr_len);
+ a->data.resident.value_length =
+ cpu_to_le32((u32)new_data_size);
+ }
+ goto flush_done;
+ }
+ /*
+ * 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.
+ */
+ ntfs_attr_put_search_ctx(ctx);
+ 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 extension process.
+ */
+ err = ntfs_attr_make_non_resident(ni, attr_len);
+ if (likely(!err))
+ goto retry_extend;
+ /*
+ * 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)) {
+ /* Only emit errors when the write will fail completely. */
+ read_lock_irqsave(&ni->size_lock, flags);
+ allocated_size = ni->allocated_size;
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot extend allocation of "
+ "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. */
+ read_lock_irqsave(&ni->size_lock, flags);
+ allocated_size = ni->allocated_size;
+ read_unlock_irqrestore(&ni->size_lock, flags);
+ if (start < 0 || start >= allocated_size) {
+ 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_extend:
+ BUG_ON(!NInoNonResident(ni));
+ if (new_alloc_size == allocated_size) {
+ BUG_ON(vcn);
+ goto alloc_done;
+ }
+ /*
+ * If the data starts after the end of the old allocation, this is a
+ * $DATA attribute and sparse attributes are enabled on the volume and
+ * for this inode, then create a sparse region between the old
+ * allocated size and the start of the data. Otherwise simply proceed
+ * with filling the whole space between the old allocated size and the
+ * new allocated size with clusters.
+ */
+ if ((start >= 0 && start <= allocated_size) || ni->type != AT_DATA ||
+ !NVolSparseEnabled(vol) || NInoSparseDisabled(ni))
+ goto skip_sparse;
+ // TODO: This is not implemented yet. We just fill in with real
+ // clusters for now...
+ ntfs_debug("Inserting holes is not-implemented yet. Falling back to "
+ "allocating real clusters instead.");
+skip_sparse:
+ rl = ni->runlist.rl;
+ if (likely(rl)) {
+ /* Seek to the end of the runlist. */
+ while (rl->length)
+ rl++;
+ }
+ /* If this attribute extent is not mapped, map it now. */
+ if (unlikely(!rl || rl->lcn == LCN_RL_NOT_MAPPED ||
+ (rl->lcn == LCN_ENOENT && rl > ni->runlist.rl &&
+ (rl-1)->lcn == LCN_RL_NOT_MAPPED))) {
+ if (!rl && !allocated_size)
+ goto first_alloc;
+ rl = ntfs_mapping_pairs_decompress(vol, a, ni->runlist.rl);
+ if (IS_ERR(rl)) {
+ err = PTR_ERR(rl);
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot extend allocation "
+ "of inode 0x%lx, attribute "
+ "type 0x%x, because the "
+ "mapping of a runlist "
+ "fragment failed with error "
+ "code %i.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type),
+ err);
+ if (err != -ENOMEM)
+ err = -EIO;
+ goto err_out;
+ }
+ ni->runlist.rl = rl;
+ /* Seek to the end of the runlist. */
+ while (rl->length)
+ rl++;
+ }
+ /*
+ * We now know the runlist of the last extent is mapped and @rl is at
+ * the end of the runlist. We want to begin allocating clusters
+ * starting at the last allocated cluster to reduce fragmentation. If
+ * there are no valid LCNs in the attribute we let the cluster
+ * allocator choose the starting cluster.
+ */
+ /* If the last LCN is a hole or simillar seek back to last real LCN. */
+ while (rl->lcn < 0 && rl > ni->runlist.rl)
+ rl--;
+first_alloc:
+ // FIXME: Need to implement partial allocations so at least part of the
+ // write can be performed when start >= 0. (Needed for POSIX write(2)
+ // conformance.)
+ rl2 = ntfs_cluster_alloc(vol, allocated_size >> vol->cluster_size_bits,
+ (new_alloc_size - allocated_size) >>
+ vol->cluster_size_bits, (rl && (rl->lcn >= 0)) ?
+ rl->lcn + rl->length : -1, DATA_ZONE, true);
+ if (IS_ERR(rl2)) {
+ err = PTR_ERR(rl2);
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot extend allocation of "
+ "inode 0x%lx, attribute type 0x%x, "
+ "because the allocation of clusters "
+ "failed with error code %i.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type), err);
+ if (err != -ENOMEM && err != -ENOSPC)
+ err = -EIO;
+ goto err_out;
+ }
+ rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
+ if (IS_ERR(rl)) {
+ err = PTR_ERR(rl);
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot extend allocation of "
+ "inode 0x%lx, attribute type 0x%x, "
+ "because the runlist merge failed "
+ "with error code %i.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type), err);
+ if (err != -ENOMEM)
+ err = -EIO;
+ if (ntfs_cluster_free_from_rl(vol, rl2)) {
+ ntfs_error(vol->sb, "Failed to release allocated "
+ "cluster(s) in error code path. Run "
+ "chkdsk to recover the lost "
+ "cluster(s).");
+ NVolSetErrors(vol);
+ }
+ ntfs_free(rl2);
+ goto err_out;
+ }
+ ni->runlist.rl = rl;
+ ntfs_debug("Allocated 0x%llx clusters.", (long long)(new_alloc_size -
+ allocated_size) >> vol->cluster_size_bits);
+ /* Find the runlist element with which the attribute extent starts. */
+ ll = sle64_to_cpu(a->data.non_resident.lowest_vcn);
+ rl2 = ntfs_rl_find_vcn_nolock(rl, ll);
+ BUG_ON(!rl2);
+ BUG_ON(!rl2->length);
+ BUG_ON(rl2->lcn < LCN_HOLE);
+ mp_rebuilt = false;
+ /* 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)) {
+ err = mp_size;
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot extend allocation of "
+ "inode 0x%lx, attribute type 0x%x, "
+ "because determining the size for the "
+ "mapping pairs failed with error code "
+ "%i.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type), err);
+ err = -EIO;
+ goto undo_alloc;
+ }
+ /* Extend the attribute record to fit the bigger mapping pairs array. */
+ 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));
+ if (unlikely(err)) {
+ BUG_ON(err != -ENOSPC);
+ // TODO: Deal with this by moving this extent to a new mft
+ // record or by starting a new extent in a new mft record,
+ // possibly by extending this extent partially and filling it
+ // and creating a new extent for the remainder, or by making
+ // other attributes non-resident and/or by moving other
+ // attributes out of this mft record.
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Not enough space in the mft "
+ "record for the extended attribute "
+ "record. This case is not "
+ "implemented yet.");
+ err = -EOPNOTSUPP;
+ goto undo_alloc;
+ }
+ mp_rebuilt = true;
+ /* Generate the mapping pairs array directly into the attr record. */
+ err = 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(err)) {
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot extend allocation of "
+ "inode 0x%lx, attribute type 0x%x, "
+ "because building the mapping pairs "
+ "failed with error code %i.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type), err);
+ err = -EIO;
+ goto undo_alloc;
+ }
+ /* Update the highest_vcn. */
+ a->data.non_resident.highest_vcn = cpu_to_sle64((new_alloc_size >>
+ vol->cluster_size_bits) - 1);
+ /*
+ * We now have extended the allocated size of the attribute. 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);
+ err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+ CASE_SENSITIVE, 0, NULL, 0, ctx);
+ if (unlikely(err))
+ goto restore_undo_alloc;
+ /* @m is not used any more so no need to set it. */
+ a = ctx->attr;
+ }
+ 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);
+ /*
+ * FIXME: This would fail if @ni is a directory, $MFT, or an index,
+ * since those can have sparse/compressed set. For example can be
+ * set compressed even though it is not compressed itself and in that
+ * case the bit means that files are to be created compressed in the
+ * directory... At present this is ok as this code is only called for
+ * regular files, and only for their $DATA attribute(s).
+ * FIXME: The calculation is wrong if we created a hole above. For now
+ * it does not matter as we never create holes.
+ */
+ if (NInoSparse(ni) || NInoCompressed(ni)) {
+ ni->itype.compressed.size += new_alloc_size - allocated_size;
+ 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);
+alloc_done:
+ if (new_data_size >= 0) {
+ BUG_ON(new_data_size <
+ sle64_to_cpu(a->data.non_resident.data_size));
+ a->data.non_resident.data_size = cpu_to_sle64(new_data_size);
+ }
+flush_done:
+ /* Ensure the changes make it to disk. */
+ flush_dcache_mft_record_page(ctx->ntfs_ino);
+ mark_mft_record_dirty(ctx->ntfs_ino);
+done:
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(base_ni);
+ up_write(&ni->runlist.lock);
+ ntfs_debug("Done, new_allocated_size 0x%llx.",
+ (unsigned long long)new_alloc_size);
+ return new_alloc_size;
+restore_undo_alloc:
+ if (start < 0 || start >= allocated_size)
+ ntfs_error(vol->sb, "Cannot complete extension of allocation "
+ "of inode 0x%lx, attribute type 0x%x, because "
+ "lookup of first attribute extent failed with "
+ "error code %i.", vi->i_ino,
+ (unsigned)le32_to_cpu(ni->type), err);
+ if (err == -ENOENT)
+ err = -EIO;
+ ntfs_attr_reinit_search_ctx(ctx);
+ if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
+ allocated_size >> vol->cluster_size_bits, NULL, 0,
+ ctx)) {
+ ntfs_error(vol->sb, "Failed to find last attribute extent of "
+ "attribute in error code path. Run chkdsk to "
+ "recover.");
+ write_lock_irqsave(&ni->size_lock, flags);
+ ni->allocated_size = new_alloc_size;
+ /*
+ * FIXME: This would fail if @ni is a directory... See above.
+ * FIXME: The calculation is wrong if we created a hole above.
+ * For now it does not matter as we never create holes.
+ */
+ if (NInoSparse(ni) || NInoCompressed(ni)) {
+ ni->itype.compressed.size += new_alloc_size -
+ allocated_size;
+ vi->i_blocks = ni->itype.compressed.size >> 9;
+ } else
+ vi->i_blocks = new_alloc_size >> 9;
+ write_unlock_irqrestore(&ni->size_lock, flags);
+ ntfs_attr_put_search_ctx(ctx);
+ unmap_mft_record(base_ni);
+ up_write(&ni->runlist.lock);
+ /*
+ * The only thing that is now wrong is the allocated size of the
+ * base attribute extent which chkdsk should be able to fix.
+ */
+ NVolSetErrors(vol);
+ return err;
+ }
+ ctx->attr->data.non_resident.highest_vcn = cpu_to_sle64(
+ (allocated_size >> vol->cluster_size_bits) - 1);
+undo_alloc:
+ ll = allocated_size >> vol->cluster_size_bits;
+ if (ntfs_cluster_free(ni, ll, -1, ctx) < 0) {
+ ntfs_error(vol->sb, "Failed to release allocated cluster(s) "
+ "in error code path. Run chkdsk to recover "
+ "the lost cluster(s).");
+ NVolSetErrors(vol);
+ }
+ m = ctx->mrec;
+ a = ctx->attr;
+ /*
+ * If the runlist truncation fails 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 (ntfs_rl_truncate_nolock(vol, &ni->runlist, ll) || IS_ERR(m)) {
+ ntfs_error(vol->sb, "Failed to %s in error code path. Run "
+ "chkdsk to recover.", IS_ERR(m) ?
+ "restore attribute search context" :
+ "truncate attribute runlist");
+ NVolSetErrors(vol);
+ } else if (mp_rebuilt) {
+ if (ntfs_attr_record_resize(m, a, attr_len)) {
+ ntfs_error(vol->sb, "Failed to restore attribute "
+ "record in error code path. Run "
+ "chkdsk to recover.");
+ NVolSetErrors(vol);
+ } else /* if (success) */ {
+ if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
+ a->data.non_resident.
+ mapping_pairs_offset), attr_len -
+ le16_to_cpu(a->data.non_resident.
+ mapping_pairs_offset), rl2, ll, -1,
+ NULL)) {
+ ntfs_error(vol->sb, "Failed to restore "
+ "mapping pairs array in error "
+ "code path. Run chkdsk to "
+ "recover.");
+ NVolSetErrors(vol);
+ }
+ flush_dcache_mft_record_page(ctx->ntfs_ino);
+ mark_mft_record_dirty(ctx->ntfs_ino);
+ }
+ }
+err_out:
+ if (ctx)
+ ntfs_attr_put_search_ctx(ctx);
+ if (m)
+ unmap_mft_record(base_ni);
+ up_write(&ni->runlist.lock);
+conv_err_out:
+ ntfs_debug("Failed. Returning error code %i.", err);
+ return err;
+}
+
+/**
+ * ntfs_attr_set - fill (a part of) an attribute with a byte
+ * @ni: ntfs inode describing the attribute to fill
+ * @ofs: offset inside the attribute at which to start to fill
+ * @cnt: number of bytes to fill
+ * @val: the unsigned 8-bit value with which to fill the attribute
+ *
+ * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at
+ * byte offset @ofs inside the attribute with the constant byte @val.
+ *
+ * This function is effectively like memset() applied to an ntfs attribute.
+ * Note thie function actually only operates on the page cache pages belonging
+ * to the ntfs attribute and it marks them dirty after doing the memset().
+ * Thus it relies on the vm dirty page write code paths to cause the modified
+ * pages to be written to the mft record/disk.
+ *
+ * Return 0 on success and -errno on error. An error code of -ESPIPE means
+ * that @ofs + @cnt were outside the end of the attribute and no write was
+ * performed.
+ */
+int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
+{
+ ntfs_volume *vol = ni->vol;
+ struct address_space *mapping;
+ struct page *page;
+ u8 *kaddr;
+ pgoff_t idx, end;
+ unsigned start_ofs, end_ofs, size;
+
+ ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.",
+ (long long)ofs, (long long)cnt, val);
+ BUG_ON(ofs < 0);
+ BUG_ON(cnt < 0);
+ if (!cnt)
+ goto done;
+ /*
+ * FIXME: Compressed and encrypted attributes are not supported when
+ * writing and we should never have gotten here for them.
+ */
+ BUG_ON(NInoCompressed(ni));
+ BUG_ON(NInoEncrypted(ni));
+ mapping = VFS_I(ni)->i_mapping;
+ /* Work out the starting index and page offset. */
+ idx = ofs >> PAGE_CACHE_SHIFT;
+ start_ofs = ofs & ~PAGE_CACHE_MASK;
+ /* Work out the ending index and page offset. */
+ end = ofs + cnt;
+ end_ofs = end & ~PAGE_CACHE_MASK;
+ /* If the end is outside the inode size return -ESPIPE. */
+ if (unlikely(end > i_size_read(VFS_I(ni)))) {
+ ntfs_error(vol->sb, "Request exceeds end of attribute.");
+ return -ESPIPE;
+ }
+ end >>= PAGE_CACHE_SHIFT;
+ /* If there is a first partial page, need to do it the slow way. */
+ if (start_ofs) {
+ page = read_mapping_page(mapping, idx, NULL);
+ if (IS_ERR(page)) {
+ ntfs_error(vol->sb, "Failed to read first partial "
+ "page (error, index 0x%lx).", idx);
+ return PTR_ERR(page);
+ }
+ /*
+ * If the last page is the same as the first page, need to
+ * limit the write to the end offset.
+ */
+ size = PAGE_CACHE_SIZE;
+ if (idx == end)
+ size = end_ofs;
+ kaddr = kmap_atomic(page);
+ memset(kaddr + start_ofs, val, size - start_ofs);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ set_page_dirty(page);
+ page_cache_release(page);
+ balance_dirty_pages_ratelimited(mapping);
+ cond_resched();
+ if (idx == end)
+ goto done;
+ idx++;
+ }
+ /* Do the whole pages the fast way. */
+ for (; idx < end; idx++) {
+ /* Find or create the current page. (The page is locked.) */
+ page = grab_cache_page(mapping, idx);
+ if (unlikely(!page)) {
+ ntfs_error(vol->sb, "Insufficient memory to grab "
+ "page (index 0x%lx).", idx);
+ return -ENOMEM;
+ }
+ kaddr = kmap_atomic(page);
+ memset(kaddr, val, PAGE_CACHE_SIZE);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ /*
+ * If the page has buffers, mark them uptodate since buffer
+ * state and not page state is definitive in 2.6 kernels.
+ */
+ if (page_has_buffers(page)) {
+ struct buffer_head *bh, *head;
+
+ bh = head = page_buffers(page);
+ do {
+ set_buffer_uptodate(bh);
+ } while ((bh = bh->b_this_page) != head);
+ }
+ /* Now that buffers are uptodate, set the page uptodate, too. */
+ SetPageUptodate(page);
+ /*
+ * Set the page and all its buffers dirty and mark the inode
+ * dirty, too. The VM will write the page later on.
+ */
+ set_page_dirty(page);
+ /* Finally unlock and release the page. */
+ unlock_page(page);
+ page_cache_release(page);
+ balance_dirty_pages_ratelimited(mapping);
+ cond_resched();
+ }
+ /* If there is a last partial page, need to do it the slow way. */
+ if (end_ofs) {
+ page = read_mapping_page(mapping, idx, NULL);
+ if (IS_ERR(page)) {
+ ntfs_error(vol->sb, "Failed to read last partial page "
+ "(error, index 0x%lx).", idx);
+ return PTR_ERR(page);
+ }
+ kaddr = kmap_atomic(page);
+ memset(kaddr, val, end_ofs);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ set_page_dirty(page);
+ page_cache_release(page);
+ balance_dirty_pages_ratelimited(mapping);
+ cond_resched();
+ }
+done:
+ ntfs_debug("Done.");
+ return 0;
+}
+
+#endif /* NTFS_RW */
Code Review / kvmfornfv.git / blobdiff