| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Anton Altaparmakov | 9838 | 98.09% | 70 | 79.55% |
| Hawkins Jiawei | 90 | 0.90% | 2 | 2.27% |
| ChenXiaoSong | 41 | 0.41% | 1 | 1.14% |
| Richard Knutsson | 28 | 0.28% | 1 | 1.14% |
| Kirill A. Shutemov | 14 | 0.14% | 1 | 1.14% |
| Christoph Hellwig | 3 | 0.03% | 1 | 1.14% |
| Pekka J Enberg | 2 | 0.02% | 1 | 1.14% |
| Lucas De Marchi | 2 | 0.02% | 1 | 1.14% |
| Linus Torvalds (pre-git) | 2 | 0.02% | 1 | 1.14% |
| Nicholas Piggin | 2 | 0.02% | 1 | 1.14% |
| Jes Sorensen | 1 | 0.01% | 1 | 1.14% |
| Christoph Lameter | 1 | 0.01% | 1 | 1.14% |
| Deming Wang | 1 | 0.01% | 1 | 1.14% |
| Thomas Gleixner | 1 | 0.01% | 1 | 1.14% |
| Li Yang | 1 | 0.01% | 1 | 1.14% |
| Matthew Wilcox | 1 | 0.01% | 1 | 1.14% |
| Linus Torvalds | 1 | 0.01% | 1 | 1.14% |
| Robert P. J. Day | 1 | 0.01% | 1 | 1.14% |
| Total | 10030 | 88 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * 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 */ #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; get_page(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) put_page(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))) { u8 *mrec_end = (u8 *)ctx->mrec + le32_to_cpu(ctx->mrec->bytes_allocated); u8 *name_end; /* check whether ATTR_RECORD wrap */ if ((u8 *)a < (u8 *)ctx->mrec) break; /* check whether Attribute Record Header is within bounds */ if ((u8 *)a > mrec_end || (u8 *)a + sizeof(ATTR_RECORD) > mrec_end) break; /* check whether ATTR_RECORD's name is within bounds */ name_end = (u8 *)a + le16_to_cpu(a->name_offset) + a->name_length * sizeof(ntfschar); if (name_end > mrec_end) 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; /* check whether ATTR_RECORD's length wrap */ if ((u8 *)a + le32_to_cpu(a->length) < (u8 *)a) break; /* check whether ATTR_RECORD's length is within bounds */ if ((u8 *)a + le32_to_cpu(a->length) > mrec_end) 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_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 ->read_folio * 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); put_page(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); put_page(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 this 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_SHIFT; start_ofs = ofs & ~PAGE_MASK; /* Work out the ending index and page offset. */ end = ofs + cnt; end_ofs = end & ~PAGE_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_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_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); put_page(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_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); put_page(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); put_page(page); balance_dirty_pages_ratelimited(mapping); cond_resched(); } done: ntfs_debug("Done."); return 0; } #endif /* NTFS_RW */
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