3  * attrib.c - NTFS attribute operations.  Part of the Linux-NTFS project.
28  * @ctx:	active attribute search context if present or NULL if not
40  * attribute on return as on entry.  However, the actual pointers in @ctx may
54  * the attribute has zero allocated size, i.e. there simply is no runlist.
114 		 * If we already have the attribute extent containing @vcn in  in ntfs_map_runlist_nolock()
118 		 * the right attribute extent.  in ntfs_map_runlist_nolock()
145 			 * needed attribute extent.  in ntfs_map_runlist_nolock()
185 		 * If there is no attribute list, restoring the search context  in ntfs_map_runlist_nolock()
187 		 * the caller supplied context.  If there is an attribute list,  in ntfs_map_runlist_nolock()
299  * @ni:			ntfs inode of the attribute whose runlist to search
303  * Find the virtual cluster number @vcn in the runlist of the ntfs attribute
307  * If the @vcn is not mapped yet, the attempt is made to map the attribute
397  * @ctx:	active attribute search context if present or NULL if not
402  * If the @vcn is not mapped yet, the attempt is made to map the attribute
413  * attribute on return as on entry.  However, the actual pointers in @ctx may
519  * ntfs_attr_find - find (next) attribute in mft record
520  * @type:	attribute type to find
521  * @name:	attribute name to find (optional, i.e. NULL means don't care)
522  * @name_len:	attribute name length (only needed if @name present)
524  * @val:	attribute value to find (optional, resident attributes only)
525  * @val_len:	attribute value length
526  * @ctx:	search context with mft record and attribute to search from
533  * attribute of @type, optionally @name and @val.
535  * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will
536  * point to the found attribute.
538  * If the attribute is not found, ntfs_attr_find() returns -ENOENT and
539  * @ctx->attr will point to the attribute before which the attribute being
555  * If @name is not present (NULL), we assume that the unnamed attribute is
558  * Finally, the resident attribute value @val is looked for, if present.  If
562  * presence of an attribute list attribute (unless it is the one being searched
563  * for, obviously).  If you need to take attribute lists into consideration,
567  * attribute list attribute only. - Note that it is possible that the first
568  * extent is only in the attribute list while the last extent is in the base
572  * Warning: Never use @val when looking for attribute types which can be
586 	 * attribute following that, if @ctx->is_first is 'true'.  in ntfs_attr_find()
608 		 * missing, assume we want an unnamed attribute.  in ntfs_attr_find()
611 			/* The search failed if the found attribute is named. */  in ntfs_attr_find()
626 			 * matching attribute.  in ntfs_attr_find()
644 		 * The names match or @name not present and attribute is  in ntfs_attr_find()
645 		 * unnamed.  If no @val specified, we have found the attribute  in ntfs_attr_find()
659 			 * If @val collates before the current attribute's  in ntfs_attr_find()
660 			 * value, there is no matching attribute.  in ntfs_attr_find()
681  * load_attribute_list - load an attribute list into memory
683  * @runlist:		runlist of the attribute list
686  * @initialized_size:	initialized size of the attribute list
724 		ntfs_error(sb, "Cannot read attribute list since runlist is "  in load_attribute_list()
734 		/* The attribute list cannot be sparse. */  in load_attribute_list()
737 					"read attribute list.");  in load_attribute_list()
750 						"read attribute list.");  in load_attribute_list()
773 		 * Note: The attribute list can be smaller than its allocation  in load_attribute_list()
786 	ntfs_error(sb, "Attribute list buffer overflow. Read attribute list "  in load_attribute_list()
794  * ntfs_external_attr_find - find an attribute in the attribute list of an inode
795  * @type:	attribute type to find
796  * @name:	attribute name to find (optional, i.e. NULL means don't care)
797  * @name_len:	attribute name length (only needed if @name present)
800  * @val:	attribute value to find (optional, resident attributes only)
801  * @val_len:	attribute value length
802  * @ctx:	search context with mft record and attribute to search from
807  * Find an attribute by searching the attribute list for the corresponding
808  * attribute list entry.  Having found the entry, map the mft record if the
809  * attribute is in a different mft record/inode, ntfs_attr_find() the attribute
817  * After finishing with the attribute/mft record you need to call
821  * If the attribute is found, ntfs_external_attr_find() returns 0 and
822  * @ctx->attr will point to the found attribute.  @ctx->mrec will point to the
824  * the attribute list entry for the attribute.
826  * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and
827  * @ctx->attr will point to the attribute in the base mft record before which
828  * the attribute being searched for would need to be inserted if such an action
830  * @ctx->attr is located and @ctx->al_entry will point to the attribute list
831  * entry of the attribute before which the attribute being searched for would
834  * Thus to insert the not found attribute, one wants to add the attribute to
836  * attribute should be placed in a newly allocated extent mft record.  The
837  * attribute list entry for the inserted attribute should be inserted in the
838  * attribute list attribute at @ctx->al_entry.
876 	 * Iterate over entries in attribute list starting at @ctx->al_entry,  in ntfs_external_attr_find()
891 		/* Catch the end of the attribute list. */  in ntfs_external_attr_find()
907 		 * missing, assume we want an unnamed attribute.  in ntfs_external_attr_find()
923 			 * matching attribute.  in ntfs_external_attr_find()
947 		 * The names match or @name not present and attribute is  in ntfs_external_attr_find()
949 		 * next attribute list entry still fits @lowest_vcn.  Otherwise  in ntfs_external_attr_find()
970 						"reference in attribute list "  in ntfs_external_attr_find()
1012 		 * mft record containing the attribute represented by the  in ntfs_external_attr_find()
1017 		 * attribute in this mft record but this would be less  in ntfs_external_attr_find()
1019 		 * the attribute instance numbers for example which become  in ntfs_external_attr_find()
1020 		 * important when one plays with attribute lists.  Also,  in ntfs_external_attr_find()
1021 		 * because a proper match has been found in the attribute list  in ntfs_external_attr_find()
1042 		 * attribute list entry and the attribute record, there is  in ntfs_external_attr_find()
1066 		/* Proceed to the next attribute in the current mft record. */  in ntfs_external_attr_find()
1072 				"attribute list attribute.%s", base_ni->mft_no,  in ntfs_external_attr_find()
1097 	 * The attribute was not found.  Before we return, we want to ensure  in ntfs_external_attr_find()
1099 	 * attribute should be inserted in the base mft record.  Since we also  in ntfs_external_attr_find()
1121 	 * keep enumerating until we get an attribute not found response (or  in ntfs_external_attr_find()
1122 	 * another error), otherwise we would keep returning the same attribute  in ntfs_external_attr_find()
1135  * ntfs_attr_lookup - find an attribute in an ntfs inode
1136  * @type:	attribute type to find
1137  * @name:	attribute name to find (optional, i.e. NULL means don't care)
1138  * @name_len:	attribute name length (only needed if @name present)
1141  * @val:	attribute value to find (optional, resident attributes only)
1142  * @val_len:	attribute value length
1143  * @ctx:	search context with mft record and attribute to search from
1145  * Find an attribute in an ntfs inode.  On first search @ctx->ntfs_ino must
1149  * This function transparently handles attribute lists and @ctx is used to
1152  * After finishing with the attribute/mft record you need to call
1158  * When 0, @ctx->attr is the found attribute and it is in mft record
1159  * @ctx->mrec.  If an attribute list attribute is present, @ctx->al_entry is
1160  * the attribute list entry of the found attribute.
1162  * When -ENOENT, @ctx->attr is the attribute which collates just after the
1163  * attribute being searched for, i.e. if one wants to add the attribute to the
1164  * mft record this is the correct place to insert it into.  If an attribute
1165  * list attribute is present, @ctx->al_entry is the attribute list entry which
1166  * collates just after the attribute list entry of the attribute being searched
1167  * for, i.e. if one wants to add the attribute to the mft record this is the
1168  * correct place to insert its attribute list entry into.
1196  * ntfs_attr_init_search_ctx - initialize an attribute search context
1197  * @ctx:	attribute search context to initialize
1201  * Initialize the attribute search context @ctx with @ni and @mrec.
1217  * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context
1218  * @ctx:	attribute search context to reinitialize
1220  * Reinitialize the attribute search context @ctx, unmapping an associated
1223  * This is used when a search for a new attribute is being started to reset
1229 		/* No attribute list. */  in ntfs_attr_reinit_search_ctx()
1240 	} /* Attribute list. */  in ntfs_attr_reinit_search_ctx()
1248  * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context
1252  * Allocate a new attribute search context, initialize it with @ni and @mrec,
1266  * ntfs_attr_put_search_ctx - release an attribute search context
1267  * @ctx:	attribute search context to free
1269  * Release the attribute search context @ctx, unmapping an associated extent
1283  * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file
1284  * @vol:	ntfs volume to which the attribute belongs
1285  * @type:	attribute type which to find
1287  * Search for the attribute definition record corresponding to the attribute
1290  * Return the attribute type definition record if found and NULL if not found.
1304 		/* We found the attribute; return it. */  in ntfs_attr_find_in_attrdef()
1310 	/* Attribute not found. */  in ntfs_attr_find_in_attrdef()
1311 	ntfs_debug("Attribute type 0x%x not found in $AttrDef.",  in ntfs_attr_find_in_attrdef()
1317  * ntfs_attr_size_bounds_check - check a size of an attribute type for validity
1318  * @vol:	ntfs volume to which the attribute belongs
1319  * @type:	attribute type which to check
1322  * Check whether the @size in bytes is valid for an attribute of @type on the
1325  * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not
1340 	/* Get the $AttrDef entry for the attribute @type. */  in ntfs_attr_size_bounds_check()
1354  * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident
1355  * @vol:	ntfs volume to which the attribute belongs
1356  * @type:	attribute type which to check
1358  * Check whether the attribute of @type on the ntfs volume @vol is allowed to
1361  * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, and
1362  * -ENOENT if the attribute is not listed in $AttrDef.
1368 	/* Find the attribute definition record in $AttrDef. */  in ntfs_attr_can_be_non_resident()
1379  * ntfs_attr_can_be_resident - check if an attribute can be resident
1380  * @vol:	ntfs volume to which the attribute belongs
1381  * @type:	attribute type which to check
1383  * Check whether the attribute of @type on the ntfs volume @vol is allowed to
1389  * Return 0 if the attribute is allowed to be non-resident and -EPERM if not.
1391  * Warning: In the system file $MFT the attribute $Bitmap must be non-resident
1404  * ntfs_attr_record_resize - resize an attribute record
1405  * @m:		mft record containing attribute record
1406  * @a:		attribute record to resize
1407  * @new_size:	new size in bytes to which to resize the attribute record @a
1409  * Resize the attribute record @a, i.e. the resident part of the attribute, in
1427 	/* If the actual attribute length has changed, move things around. */  in ntfs_attr_record_resize()
1448  * ntfs_resident_attr_value_resize - resize the value of a resident attribute
1449  * @m:		mft record containing attribute record
1450  * @a:		attribute record whose value to resize
1451  * @new_size:	new size in bytes to which to resize the attribute value of @a
1453  * Resize the value of the attribute @a in the mft record @m to @new_size bytes.
1470 	/* Resize the resident part of the attribute record. */  in ntfs_resident_attr_value_resize()
1475 	 * The resize succeeded!  If we made the attribute value bigger, clear  in ntfs_resident_attr_value_resize()
1482 	/* Finally update the length of the attribute value. */  in ntfs_resident_attr_value_resize()
1488  * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
1489  * @ni:		ntfs inode describing the attribute to convert
1490  * @data_size:	size of the resident data to copy to the non-resident attribute
1492  * Convert the resident ntfs attribute described by the ntfs inode @ni to a
1495  * @data_size must be equal to the attribute value size.  This is needed since
1503  *	-EPERM	- The attribute is not allowed to be non-resident.
1506  *	-EINVAL	- Attribute not defined on the volume.
1513  * again in case the attribute may then fit in a resident state so no need to
1516  * NOTE to self: No changes in the attribute list are required to move from
1517  *		 a resident to a non-resident attribute.
1538 	/* Check that the attribute is allowed to be non-resident. */  in ntfs_attr_make_non_resident()
1542 			ntfs_debug("Attribute is not allowed to be "  in ntfs_attr_make_non_resident()
1545 			ntfs_debug("Attribute not defined on the NTFS "  in ntfs_attr_make_non_resident()
1570 		/* Start by allocating clusters to hold the attribute value. */  in ntfs_attr_make_non_resident()
1635 	 * attribute record.  in ntfs_attr_make_non_resident()
1640 	 * attribute value.  in ntfs_attr_make_non_resident()
1654 	/* Backup the attribute flag. */  in ntfs_attr_make_non_resident()
1656 	/* Resize the resident part of the attribute record. */  in ntfs_attr_make_non_resident()
1661 	 * Convert the resident part of the attribute record to describe a  in ntfs_attr_make_non_resident()
1662 	 * non-resident attribute.  in ntfs_attr_make_non_resident()
1665 	/* Move the attribute name if it exists and update the offset. */  in ntfs_attr_make_non_resident()
1689 	/* Generate the mapping pairs array into the attribute record. */  in ntfs_attr_make_non_resident()
1697 	/* Setup the in-memory attribute structure to be non-resident. */  in ntfs_attr_make_non_resident()
1742 	/* Convert the attribute back into a resident attribute. */  in ntfs_attr_make_non_resident()
1744 	/* Move the attribute name if it exists and update the offset. */  in ntfs_attr_make_non_resident()
1753 	/* Resize the resident part of the attribute record. */  in ntfs_attr_make_non_resident()
1759 		 * If the old size is too small, truncate the attribute,  in ntfs_attr_make_non_resident()
1769 					"to non-resident attribute "  in ntfs_attr_make_non_resident()
1771 					"attribute type 0x%x from %i bytes to "  in ntfs_attr_make_non_resident()
1779 					!ni->name_len) ? "FILE": "ATTRIBUTE");  in ntfs_attr_make_non_resident()
1792 	/* Copy the data from the page back to the attribute value. */  in ntfs_attr_make_non_resident()
1832  * ntfs_attr_extend_allocation - extend the allocated space of an attribute
1833  * @ni:			ntfs inode of the attribute whose allocation to extend
1838  * Extend the allocated space of an attribute described by the ntfs inode @ni
1847  * of the attribute is extended to @new_data_size.  Note that the i_size of the
1848  * vfs inode is not updated.  Only the data size in the base attribute record
1853  * For resident attributes this involves resizing the attribute record and if
1855  * converting the attribute to a non-resident attribute which in turn involves
1856  * extending the allocation of a non-resident attribute as described below.
1861  * updating the mapping pairs array of the attribute.  This in turn involves
1862  * resizing the attribute record and if necessary moving it and/or other
1863  * attributes into extent mft records and/or splitting the attribute record
1864  * into multiple extent attribute records.
1866  * Also, the attribute list attribute is updated if present and in some of the
1868  * an attribute list attribute is created if not already present.
1882  * attribute can be resized safely and so that it can for example be converted
1885  * TODO: At present attribute list attribute handling is not implemented.
1888  * than the $DATA attribute(s) of an uncompressed and unencrypted file.
1911 	ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "  in ntfs_attr_extend_allocation()
1943 						"of inode 0x%lx, attribute "  in ntfs_attr_extend_allocation()
1947 						"this attribute type.",  in ntfs_attr_extend_allocation()
1952 						"of inode 0x%lx, attribute "  in ntfs_attr_extend_allocation()
1954 						"attribute type is not "  in ntfs_attr_extend_allocation()
2001 	 * just converted the attribute from resident to non-resident it is  in ntfs_attr_extend_allocation()
2011 		 * We want the first attribute extent so that we can update the  in ntfs_attr_extend_allocation()
2029 	/* The total length of the attribute value. */  in ntfs_attr_extend_allocation()
2032 	 * Extend the attribute record to be able to store the new attribute  in ntfs_attr_extend_allocation()
2064 	 * Not enough space in the mft record, try to make the attribute  in ntfs_attr_extend_allocation()
2072 	 * permitted for this attribute type or there not being enough space,  in ntfs_attr_extend_allocation()
2082 					"inode 0x%lx, attribute type 0x%x, "  in ntfs_attr_extend_allocation()
2084 					"to non-resident attribute failed "  in ntfs_attr_extend_allocation()
2099 					"attribute value.  This case is not "  in ntfs_attr_extend_allocation()
2102 			ntfs_error(vol->sb, "This attribute type may not be "  in ntfs_attr_extend_allocation()
2113 	 * Both the attribute list attribute and the standard information  in ntfs_attr_extend_allocation()
2114 	 * attribute must remain in the base inode.  Thus, if this is one of  in ntfs_attr_extend_allocation()
2127 	// TODO: Attempt to move this attribute to an extent mft record, but  in ntfs_attr_extend_allocation()
2128 	// only if it is not already the only attribute in an mft record in  in ntfs_attr_extend_allocation()
2144 	 * $DATA attribute and sparse attributes are enabled on the volume and  in ntfs_attr_extend_allocation()
2164 	/* If this attribute extent is not mapped, map it now. */  in ntfs_attr_extend_allocation()
2175 						"of inode 0x%lx, attribute "  in ntfs_attr_extend_allocation()
2195 	 * there are no valid LCNs in the attribute we let the cluster  in ntfs_attr_extend_allocation()
2213 					"inode 0x%lx, attribute type 0x%x, "  in ntfs_attr_extend_allocation()
2226 					"inode 0x%lx, attribute type 0x%x, "  in ntfs_attr_extend_allocation()
2245 	/* Find the runlist element with which the attribute extent starts. */  in ntfs_attr_extend_allocation()
2258 					"inode 0x%lx, attribute type 0x%x, "  in ntfs_attr_extend_allocation()
2266 	/* Extend the attribute record to fit the bigger mapping pairs array. */  in ntfs_attr_extend_allocation()
2280 					"record for the extended attribute "  in ntfs_attr_extend_allocation()
2294 					"inode 0x%lx, attribute type 0x%x, "  in ntfs_attr_extend_allocation()
2305 	 * We now have extended the allocated size of the attribute.  Reflect  in ntfs_attr_extend_allocation()
2306 	 * this in the ntfs_inode structure and the attribute record.  in ntfs_attr_extend_allocation()
2310 		 * We are not in the first attribute extent, switch to it, but  in ntfs_attr_extend_allocation()
2332 	 * regular files, and only for their $DATA attribute(s).  in ntfs_attr_extend_allocation()
2364 				"of inode 0x%lx, attribute type 0x%x, because "  in ntfs_attr_extend_allocation()
2365 				"lookup of first attribute extent failed with "  in ntfs_attr_extend_allocation()
2374 		ntfs_error(vol->sb, "Failed to find last attribute extent of "  in ntfs_attr_extend_allocation()
2375 				"attribute in error code path.  Run chkdsk to "  in ntfs_attr_extend_allocation()
2396 		 * base attribute extent which chkdsk should be able to fix.  in ntfs_attr_extend_allocation()
2415 	 * longer valid, we cannot resize the attribute record or build the  in ntfs_attr_extend_allocation()
2422 				"restore attribute search context" :  in ntfs_attr_extend_allocation()
2423 				"truncate attribute runlist");  in ntfs_attr_extend_allocation()
2427 			ntfs_error(vol->sb, "Failed to restore attribute "  in ntfs_attr_extend_allocation()
2460  * ntfs_attr_set - fill (a part of) an attribute with a byte
2461  * @ni:		ntfs inode describing the attribute to fill
2462  * @ofs:	offset inside the attribute at which to start to fill
2464  * @val:	the unsigned 8-bit value with which to fill the attribute
2466  * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at
2467  * byte offset @ofs inside the attribute with the constant byte @val.
2469  * This function is effectively like memset() applied to an ntfs attribute.
2471  * to the ntfs attribute and it marks them dirty after doing the memset().
2476  * that @ofs + @cnt were outside the end of the attribute and no write was
2509 		ntfs_error(vol->sb, "Request exceeds end of attribute.");  in ntfs_attr_set()