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1538 lines
51 KiB
1538 lines
51 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/** |
|
* dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project. |
|
* |
|
* Copyright (c) 2001-2007 Anton Altaparmakov |
|
* Copyright (c) 2002 Richard Russon |
|
*/ |
|
|
|
#include <linux/buffer_head.h> |
|
#include <linux/slab.h> |
|
#include <linux/blkdev.h> |
|
|
|
#include "dir.h" |
|
#include "aops.h" |
|
#include "attrib.h" |
|
#include "mft.h" |
|
#include "debug.h" |
|
#include "ntfs.h" |
|
|
|
/** |
|
* The little endian Unicode string $I30 as a global constant. |
|
*/ |
|
ntfschar I30[5] = { cpu_to_le16('$'), cpu_to_le16('I'), |
|
cpu_to_le16('3'), cpu_to_le16('0'), 0 }; |
|
|
|
/** |
|
* ntfs_lookup_inode_by_name - find an inode in a directory given its name |
|
* @dir_ni: ntfs inode of the directory in which to search for the name |
|
* @uname: Unicode name for which to search in the directory |
|
* @uname_len: length of the name @uname in Unicode characters |
|
* @res: return the found file name if necessary (see below) |
|
* |
|
* Look for an inode with name @uname in the directory with inode @dir_ni. |
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* ntfs_lookup_inode_by_name() walks the contents of the directory looking for |
|
* the Unicode name. If the name is found in the directory, the corresponding |
|
* inode number (>= 0) is returned as a mft reference in cpu format, i.e. it |
|
* is a 64-bit number containing the sequence number. |
|
* |
|
* On error, a negative value is returned corresponding to the error code. In |
|
* particular if the inode is not found -ENOENT is returned. Note that you |
|
* can't just check the return value for being negative, you have to check the |
|
* inode number for being negative which you can extract using MREC(return |
|
* value). |
|
* |
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* Note, @uname_len does not include the (optional) terminating NULL character. |
|
* |
|
* Note, we look for a case sensitive match first but we also look for a case |
|
* insensitive match at the same time. If we find a case insensitive match, we |
|
* save that for the case that we don't find an exact match, where we return |
|
* the case insensitive match and setup @res (which we allocate!) with the mft |
|
* reference, the file name type, length and with a copy of the little endian |
|
* Unicode file name itself. If we match a file name which is in the DOS name |
|
* space, we only return the mft reference and file name type in @res. |
|
* ntfs_lookup() then uses this to find the long file name in the inode itself. |
|
* This is to avoid polluting the dcache with short file names. We want them to |
|
* work but we don't care for how quickly one can access them. This also fixes |
|
* the dcache aliasing issues. |
|
* |
|
* Locking: - Caller must hold i_mutex on the directory. |
|
* - Each page cache page in the index allocation mapping must be |
|
* locked whilst being accessed otherwise we may find a corrupt |
|
* page due to it being under ->writepage at the moment which |
|
* applies the mst protection fixups before writing out and then |
|
* removes them again after the write is complete after which it |
|
* unlocks the page. |
|
*/ |
|
MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname, |
|
const int uname_len, ntfs_name **res) |
|
{ |
|
ntfs_volume *vol = dir_ni->vol; |
|
struct super_block *sb = vol->sb; |
|
MFT_RECORD *m; |
|
INDEX_ROOT *ir; |
|
INDEX_ENTRY *ie; |
|
INDEX_ALLOCATION *ia; |
|
u8 *index_end; |
|
u64 mref; |
|
ntfs_attr_search_ctx *ctx; |
|
int err, rc; |
|
VCN vcn, old_vcn; |
|
struct address_space *ia_mapping; |
|
struct page *page; |
|
u8 *kaddr; |
|
ntfs_name *name = NULL; |
|
|
|
BUG_ON(!S_ISDIR(VFS_I(dir_ni)->i_mode)); |
|
BUG_ON(NInoAttr(dir_ni)); |
|
/* Get hold of the mft record for the directory. */ |
|
m = map_mft_record(dir_ni); |
|
if (IS_ERR(m)) { |
|
ntfs_error(sb, "map_mft_record() failed with error code %ld.", |
|
-PTR_ERR(m)); |
|
return ERR_MREF(PTR_ERR(m)); |
|
} |
|
ctx = ntfs_attr_get_search_ctx(dir_ni, m); |
|
if (unlikely(!ctx)) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
/* Find the index root attribute in the mft record. */ |
|
err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, |
|
0, ctx); |
|
if (unlikely(err)) { |
|
if (err == -ENOENT) { |
|
ntfs_error(sb, "Index root attribute missing in " |
|
"directory inode 0x%lx.", |
|
dir_ni->mft_no); |
|
err = -EIO; |
|
} |
|
goto err_out; |
|
} |
|
/* Get to the index root value (it's been verified in read_inode). */ |
|
ir = (INDEX_ROOT*)((u8*)ctx->attr + |
|
le16_to_cpu(ctx->attr->data.resident.value_offset)); |
|
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); |
|
/* The first index entry. */ |
|
ie = (INDEX_ENTRY*)((u8*)&ir->index + |
|
le32_to_cpu(ir->index.entries_offset)); |
|
/* |
|
* Loop until we exceed valid memory (corruption case) or until we |
|
* reach the last entry. |
|
*/ |
|
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { |
|
/* Bounds checks. */ |
|
if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie + |
|
sizeof(INDEX_ENTRY_HEADER) > index_end || |
|
(u8*)ie + le16_to_cpu(ie->key_length) > |
|
index_end) |
|
goto dir_err_out; |
|
/* |
|
* The last entry cannot contain a name. It can however contain |
|
* a pointer to a child node in the B+tree so we just break out. |
|
*/ |
|
if (ie->flags & INDEX_ENTRY_END) |
|
break; |
|
/* |
|
* We perform a case sensitive comparison and if that matches |
|
* we are done and return the mft reference of the inode (i.e. |
|
* the inode number together with the sequence number for |
|
* consistency checking). We convert it to cpu format before |
|
* returning. |
|
*/ |
|
if (ntfs_are_names_equal(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, |
|
CASE_SENSITIVE, vol->upcase, vol->upcase_len)) { |
|
found_it: |
|
/* |
|
* We have a perfect match, so we don't need to care |
|
* about having matched imperfectly before, so we can |
|
* free name and set *res to NULL. |
|
* However, if the perfect match is a short file name, |
|
* we need to signal this through *res, so that |
|
* ntfs_lookup() can fix dcache aliasing issues. |
|
* As an optimization we just reuse an existing |
|
* allocation of *res. |
|
*/ |
|
if (ie->key.file_name.file_name_type == FILE_NAME_DOS) { |
|
if (!name) { |
|
name = kmalloc(sizeof(ntfs_name), |
|
GFP_NOFS); |
|
if (!name) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
} |
|
name->mref = le64_to_cpu( |
|
ie->data.dir.indexed_file); |
|
name->type = FILE_NAME_DOS; |
|
name->len = 0; |
|
*res = name; |
|
} else { |
|
kfree(name); |
|
*res = NULL; |
|
} |
|
mref = le64_to_cpu(ie->data.dir.indexed_file); |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(dir_ni); |
|
return mref; |
|
} |
|
/* |
|
* For a case insensitive mount, we also perform a case |
|
* insensitive comparison (provided the file name is not in the |
|
* POSIX namespace). If the comparison matches, and the name is |
|
* in the WIN32 namespace, we cache the filename in *res so |
|
* that the caller, ntfs_lookup(), can work on it. If the |
|
* comparison matches, and the name is in the DOS namespace, we |
|
* only cache the mft reference and the file name type (we set |
|
* the name length to zero for simplicity). |
|
*/ |
|
if (!NVolCaseSensitive(vol) && |
|
ie->key.file_name.file_name_type && |
|
ntfs_are_names_equal(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, |
|
IGNORE_CASE, vol->upcase, vol->upcase_len)) { |
|
int name_size = sizeof(ntfs_name); |
|
u8 type = ie->key.file_name.file_name_type; |
|
u8 len = ie->key.file_name.file_name_length; |
|
|
|
/* Only one case insensitive matching name allowed. */ |
|
if (name) { |
|
ntfs_error(sb, "Found already allocated name " |
|
"in phase 1. Please run chkdsk " |
|
"and if that doesn't find any " |
|
"errors please report you saw " |
|
"this message to " |
|
"linux-ntfs-dev@lists." |
|
"sourceforge.net."); |
|
goto dir_err_out; |
|
} |
|
|
|
if (type != FILE_NAME_DOS) |
|
name_size += len * sizeof(ntfschar); |
|
name = kmalloc(name_size, GFP_NOFS); |
|
if (!name) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
name->mref = le64_to_cpu(ie->data.dir.indexed_file); |
|
name->type = type; |
|
if (type != FILE_NAME_DOS) { |
|
name->len = len; |
|
memcpy(name->name, ie->key.file_name.file_name, |
|
len * sizeof(ntfschar)); |
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} else |
|
name->len = 0; |
|
*res = name; |
|
} |
|
/* |
|
* Not a perfect match, need to do full blown collation so we |
|
* know which way in the B+tree we have to go. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
IGNORE_CASE, vol->upcase, vol->upcase_len); |
|
/* |
|
* If uname collates before the name of the current entry, there |
|
* is definitely no such name in this index but we might need to |
|
* descend into the B+tree so we just break out of the loop. |
|
*/ |
|
if (rc == -1) |
|
break; |
|
/* The names are not equal, continue the search. */ |
|
if (rc) |
|
continue; |
|
/* |
|
* Names match with case insensitive comparison, now try the |
|
* case sensitive comparison, which is required for proper |
|
* collation. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
CASE_SENSITIVE, vol->upcase, vol->upcase_len); |
|
if (rc == -1) |
|
break; |
|
if (rc) |
|
continue; |
|
/* |
|
* Perfect match, this will never happen as the |
|
* ntfs_are_names_equal() call will have gotten a match but we |
|
* still treat it correctly. |
|
*/ |
|
goto found_it; |
|
} |
|
/* |
|
* We have finished with this index without success. Check for the |
|
* presence of a child node and if not present return -ENOENT, unless |
|
* we have got a matching name cached in name in which case return the |
|
* mft reference associated with it. |
|
*/ |
|
if (!(ie->flags & INDEX_ENTRY_NODE)) { |
|
if (name) { |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(dir_ni); |
|
return name->mref; |
|
} |
|
ntfs_debug("Entry not found."); |
|
err = -ENOENT; |
|
goto err_out; |
|
} /* Child node present, descend into it. */ |
|
/* Consistency check: Verify that an index allocation exists. */ |
|
if (!NInoIndexAllocPresent(dir_ni)) { |
|
ntfs_error(sb, "No index allocation attribute but index entry " |
|
"requires one. Directory inode 0x%lx is " |
|
"corrupt or driver bug.", dir_ni->mft_no); |
|
goto err_out; |
|
} |
|
/* Get the starting vcn of the index_block holding the child node. */ |
|
vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8)); |
|
ia_mapping = VFS_I(dir_ni)->i_mapping; |
|
/* |
|
* We are done with the index root and the mft record. Release them, |
|
* otherwise we deadlock with ntfs_map_page(). |
|
*/ |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(dir_ni); |
|
m = NULL; |
|
ctx = NULL; |
|
descend_into_child_node: |
|
/* |
|
* Convert vcn to index into the index allocation attribute in units |
|
* of PAGE_SIZE and map the page cache page, reading it from |
|
* disk if necessary. |
|
*/ |
|
page = ntfs_map_page(ia_mapping, vcn << |
|
dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT); |
|
if (IS_ERR(page)) { |
|
ntfs_error(sb, "Failed to map directory index page, error %ld.", |
|
-PTR_ERR(page)); |
|
err = PTR_ERR(page); |
|
goto err_out; |
|
} |
|
lock_page(page); |
|
kaddr = (u8*)page_address(page); |
|
fast_descend_into_child_node: |
|
/* Get to the index allocation block. */ |
|
ia = (INDEX_ALLOCATION*)(kaddr + ((vcn << |
|
dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK)); |
|
/* Bounds checks. */ |
|
if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) { |
|
ntfs_error(sb, "Out of bounds check failed. Corrupt directory " |
|
"inode 0x%lx or driver bug.", dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* Catch multi sector transfer fixup errors. */ |
|
if (unlikely(!ntfs_is_indx_record(ia->magic))) { |
|
ntfs_error(sb, "Directory index record with vcn 0x%llx is " |
|
"corrupt. Corrupt inode 0x%lx. Run chkdsk.", |
|
(unsigned long long)vcn, dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
if (sle64_to_cpu(ia->index_block_vcn) != vcn) { |
|
ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " |
|
"different from expected VCN (0x%llx). " |
|
"Directory inode 0x%lx is corrupt or driver " |
|
"bug.", (unsigned long long) |
|
sle64_to_cpu(ia->index_block_vcn), |
|
(unsigned long long)vcn, dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
if (le32_to_cpu(ia->index.allocated_size) + 0x18 != |
|
dir_ni->itype.index.block_size) { |
|
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " |
|
"0x%lx has a size (%u) differing from the " |
|
"directory specified size (%u). Directory " |
|
"inode is corrupt or driver bug.", |
|
(unsigned long long)vcn, dir_ni->mft_no, |
|
le32_to_cpu(ia->index.allocated_size) + 0x18, |
|
dir_ni->itype.index.block_size); |
|
goto unm_err_out; |
|
} |
|
index_end = (u8*)ia + dir_ni->itype.index.block_size; |
|
if (index_end > kaddr + PAGE_SIZE) { |
|
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " |
|
"0x%lx crosses page boundary. Impossible! " |
|
"Cannot access! This is probably a bug in the " |
|
"driver.", (unsigned long long)vcn, |
|
dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); |
|
if (index_end > (u8*)ia + dir_ni->itype.index.block_size) { |
|
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " |
|
"inode 0x%lx exceeds maximum size.", |
|
(unsigned long long)vcn, dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* The first index entry. */ |
|
ie = (INDEX_ENTRY*)((u8*)&ia->index + |
|
le32_to_cpu(ia->index.entries_offset)); |
|
/* |
|
* Iterate similar to above big loop but applied to index buffer, thus |
|
* loop until we exceed valid memory (corruption case) or until we |
|
* reach the last entry. |
|
*/ |
|
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { |
|
/* Bounds check. */ |
|
if ((u8*)ie < (u8*)ia || (u8*)ie + |
|
sizeof(INDEX_ENTRY_HEADER) > index_end || |
|
(u8*)ie + le16_to_cpu(ie->key_length) > |
|
index_end) { |
|
ntfs_error(sb, "Index entry out of bounds in " |
|
"directory inode 0x%lx.", |
|
dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* |
|
* The last entry cannot contain a name. It can however contain |
|
* a pointer to a child node in the B+tree so we just break out. |
|
*/ |
|
if (ie->flags & INDEX_ENTRY_END) |
|
break; |
|
/* |
|
* We perform a case sensitive comparison and if that matches |
|
* we are done and return the mft reference of the inode (i.e. |
|
* the inode number together with the sequence number for |
|
* consistency checking). We convert it to cpu format before |
|
* returning. |
|
*/ |
|
if (ntfs_are_names_equal(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, |
|
CASE_SENSITIVE, vol->upcase, vol->upcase_len)) { |
|
found_it2: |
|
/* |
|
* We have a perfect match, so we don't need to care |
|
* about having matched imperfectly before, so we can |
|
* free name and set *res to NULL. |
|
* However, if the perfect match is a short file name, |
|
* we need to signal this through *res, so that |
|
* ntfs_lookup() can fix dcache aliasing issues. |
|
* As an optimization we just reuse an existing |
|
* allocation of *res. |
|
*/ |
|
if (ie->key.file_name.file_name_type == FILE_NAME_DOS) { |
|
if (!name) { |
|
name = kmalloc(sizeof(ntfs_name), |
|
GFP_NOFS); |
|
if (!name) { |
|
err = -ENOMEM; |
|
goto unm_err_out; |
|
} |
|
} |
|
name->mref = le64_to_cpu( |
|
ie->data.dir.indexed_file); |
|
name->type = FILE_NAME_DOS; |
|
name->len = 0; |
|
*res = name; |
|
} else { |
|
kfree(name); |
|
*res = NULL; |
|
} |
|
mref = le64_to_cpu(ie->data.dir.indexed_file); |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
return mref; |
|
} |
|
/* |
|
* For a case insensitive mount, we also perform a case |
|
* insensitive comparison (provided the file name is not in the |
|
* POSIX namespace). If the comparison matches, and the name is |
|
* in the WIN32 namespace, we cache the filename in *res so |
|
* that the caller, ntfs_lookup(), can work on it. If the |
|
* comparison matches, and the name is in the DOS namespace, we |
|
* only cache the mft reference and the file name type (we set |
|
* the name length to zero for simplicity). |
|
*/ |
|
if (!NVolCaseSensitive(vol) && |
|
ie->key.file_name.file_name_type && |
|
ntfs_are_names_equal(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, |
|
IGNORE_CASE, vol->upcase, vol->upcase_len)) { |
|
int name_size = sizeof(ntfs_name); |
|
u8 type = ie->key.file_name.file_name_type; |
|
u8 len = ie->key.file_name.file_name_length; |
|
|
|
/* Only one case insensitive matching name allowed. */ |
|
if (name) { |
|
ntfs_error(sb, "Found already allocated name " |
|
"in phase 2. Please run chkdsk " |
|
"and if that doesn't find any " |
|
"errors please report you saw " |
|
"this message to " |
|
"linux-ntfs-dev@lists." |
|
"sourceforge.net."); |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
goto dir_err_out; |
|
} |
|
|
|
if (type != FILE_NAME_DOS) |
|
name_size += len * sizeof(ntfschar); |
|
name = kmalloc(name_size, GFP_NOFS); |
|
if (!name) { |
|
err = -ENOMEM; |
|
goto unm_err_out; |
|
} |
|
name->mref = le64_to_cpu(ie->data.dir.indexed_file); |
|
name->type = type; |
|
if (type != FILE_NAME_DOS) { |
|
name->len = len; |
|
memcpy(name->name, ie->key.file_name.file_name, |
|
len * sizeof(ntfschar)); |
|
} else |
|
name->len = 0; |
|
*res = name; |
|
} |
|
/* |
|
* Not a perfect match, need to do full blown collation so we |
|
* know which way in the B+tree we have to go. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
IGNORE_CASE, vol->upcase, vol->upcase_len); |
|
/* |
|
* If uname collates before the name of the current entry, there |
|
* is definitely no such name in this index but we might need to |
|
* descend into the B+tree so we just break out of the loop. |
|
*/ |
|
if (rc == -1) |
|
break; |
|
/* The names are not equal, continue the search. */ |
|
if (rc) |
|
continue; |
|
/* |
|
* Names match with case insensitive comparison, now try the |
|
* case sensitive comparison, which is required for proper |
|
* collation. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
CASE_SENSITIVE, vol->upcase, vol->upcase_len); |
|
if (rc == -1) |
|
break; |
|
if (rc) |
|
continue; |
|
/* |
|
* Perfect match, this will never happen as the |
|
* ntfs_are_names_equal() call will have gotten a match but we |
|
* still treat it correctly. |
|
*/ |
|
goto found_it2; |
|
} |
|
/* |
|
* We have finished with this index buffer without success. Check for |
|
* the presence of a child node. |
|
*/ |
|
if (ie->flags & INDEX_ENTRY_NODE) { |
|
if ((ia->index.flags & NODE_MASK) == LEAF_NODE) { |
|
ntfs_error(sb, "Index entry with child node found in " |
|
"a leaf node in directory inode 0x%lx.", |
|
dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* Child node present, descend into it. */ |
|
old_vcn = vcn; |
|
vcn = sle64_to_cpup((sle64*)((u8*)ie + |
|
le16_to_cpu(ie->length) - 8)); |
|
if (vcn >= 0) { |
|
/* If vcn is in the same page cache page as old_vcn we |
|
* recycle the mapped page. */ |
|
if (old_vcn << vol->cluster_size_bits >> |
|
PAGE_SHIFT == vcn << |
|
vol->cluster_size_bits >> |
|
PAGE_SHIFT) |
|
goto fast_descend_into_child_node; |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
goto descend_into_child_node; |
|
} |
|
ntfs_error(sb, "Negative child node vcn in directory inode " |
|
"0x%lx.", dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* |
|
* No child node present, return -ENOENT, unless we have got a matching |
|
* name cached in name in which case return the mft reference |
|
* associated with it. |
|
*/ |
|
if (name) { |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
return name->mref; |
|
} |
|
ntfs_debug("Entry not found."); |
|
err = -ENOENT; |
|
unm_err_out: |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
err_out: |
|
if (!err) |
|
err = -EIO; |
|
if (ctx) |
|
ntfs_attr_put_search_ctx(ctx); |
|
if (m) |
|
unmap_mft_record(dir_ni); |
|
if (name) { |
|
kfree(name); |
|
*res = NULL; |
|
} |
|
return ERR_MREF(err); |
|
dir_err_out: |
|
ntfs_error(sb, "Corrupt directory. Aborting lookup."); |
|
goto err_out; |
|
} |
|
|
|
#if 0 |
|
|
|
// TODO: (AIA) |
|
// The algorithm embedded in this code will be required for the time when we |
|
// want to support adding of entries to directories, where we require correct |
|
// collation of file names in order not to cause corruption of the filesystem. |
|
|
|
/** |
|
* ntfs_lookup_inode_by_name - find an inode in a directory given its name |
|
* @dir_ni: ntfs inode of the directory in which to search for the name |
|
* @uname: Unicode name for which to search in the directory |
|
* @uname_len: length of the name @uname in Unicode characters |
|
* |
|
* Look for an inode with name @uname in the directory with inode @dir_ni. |
|
* ntfs_lookup_inode_by_name() walks the contents of the directory looking for |
|
* the Unicode name. If the name is found in the directory, the corresponding |
|
* inode number (>= 0) is returned as a mft reference in cpu format, i.e. it |
|
* is a 64-bit number containing the sequence number. |
|
* |
|
* On error, a negative value is returned corresponding to the error code. In |
|
* particular if the inode is not found -ENOENT is returned. Note that you |
|
* can't just check the return value for being negative, you have to check the |
|
* inode number for being negative which you can extract using MREC(return |
|
* value). |
|
* |
|
* Note, @uname_len does not include the (optional) terminating NULL character. |
|
*/ |
|
u64 ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname, |
|
const int uname_len) |
|
{ |
|
ntfs_volume *vol = dir_ni->vol; |
|
struct super_block *sb = vol->sb; |
|
MFT_RECORD *m; |
|
INDEX_ROOT *ir; |
|
INDEX_ENTRY *ie; |
|
INDEX_ALLOCATION *ia; |
|
u8 *index_end; |
|
u64 mref; |
|
ntfs_attr_search_ctx *ctx; |
|
int err, rc; |
|
IGNORE_CASE_BOOL ic; |
|
VCN vcn, old_vcn; |
|
struct address_space *ia_mapping; |
|
struct page *page; |
|
u8 *kaddr; |
|
|
|
/* Get hold of the mft record for the directory. */ |
|
m = map_mft_record(dir_ni); |
|
if (IS_ERR(m)) { |
|
ntfs_error(sb, "map_mft_record() failed with error code %ld.", |
|
-PTR_ERR(m)); |
|
return ERR_MREF(PTR_ERR(m)); |
|
} |
|
ctx = ntfs_attr_get_search_ctx(dir_ni, m); |
|
if (!ctx) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
/* Find the index root attribute in the mft record. */ |
|
err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, |
|
0, ctx); |
|
if (unlikely(err)) { |
|
if (err == -ENOENT) { |
|
ntfs_error(sb, "Index root attribute missing in " |
|
"directory inode 0x%lx.", |
|
dir_ni->mft_no); |
|
err = -EIO; |
|
} |
|
goto err_out; |
|
} |
|
/* Get to the index root value (it's been verified in read_inode). */ |
|
ir = (INDEX_ROOT*)((u8*)ctx->attr + |
|
le16_to_cpu(ctx->attr->data.resident.value_offset)); |
|
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); |
|
/* The first index entry. */ |
|
ie = (INDEX_ENTRY*)((u8*)&ir->index + |
|
le32_to_cpu(ir->index.entries_offset)); |
|
/* |
|
* Loop until we exceed valid memory (corruption case) or until we |
|
* reach the last entry. |
|
*/ |
|
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { |
|
/* Bounds checks. */ |
|
if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie + |
|
sizeof(INDEX_ENTRY_HEADER) > index_end || |
|
(u8*)ie + le16_to_cpu(ie->key_length) > |
|
index_end) |
|
goto dir_err_out; |
|
/* |
|
* The last entry cannot contain a name. It can however contain |
|
* a pointer to a child node in the B+tree so we just break out. |
|
*/ |
|
if (ie->flags & INDEX_ENTRY_END) |
|
break; |
|
/* |
|
* If the current entry has a name type of POSIX, the name is |
|
* case sensitive and not otherwise. This has the effect of us |
|
* not being able to access any POSIX file names which collate |
|
* after the non-POSIX one when they only differ in case, but |
|
* anyone doing screwy stuff like that deserves to burn in |
|
* hell... Doing that kind of stuff on NT4 actually causes |
|
* corruption on the partition even when using SP6a and Linux |
|
* is not involved at all. |
|
*/ |
|
ic = ie->key.file_name.file_name_type ? IGNORE_CASE : |
|
CASE_SENSITIVE; |
|
/* |
|
* If the names match perfectly, we are done and return the |
|
* mft reference of the inode (i.e. the inode number together |
|
* with the sequence number for consistency checking. We |
|
* convert it to cpu format before returning. |
|
*/ |
|
if (ntfs_are_names_equal(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, ic, |
|
vol->upcase, vol->upcase_len)) { |
|
found_it: |
|
mref = le64_to_cpu(ie->data.dir.indexed_file); |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(dir_ni); |
|
return mref; |
|
} |
|
/* |
|
* Not a perfect match, need to do full blown collation so we |
|
* know which way in the B+tree we have to go. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
IGNORE_CASE, vol->upcase, vol->upcase_len); |
|
/* |
|
* If uname collates before the name of the current entry, there |
|
* is definitely no such name in this index but we might need to |
|
* descend into the B+tree so we just break out of the loop. |
|
*/ |
|
if (rc == -1) |
|
break; |
|
/* The names are not equal, continue the search. */ |
|
if (rc) |
|
continue; |
|
/* |
|
* Names match with case insensitive comparison, now try the |
|
* case sensitive comparison, which is required for proper |
|
* collation. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
CASE_SENSITIVE, vol->upcase, vol->upcase_len); |
|
if (rc == -1) |
|
break; |
|
if (rc) |
|
continue; |
|
/* |
|
* Perfect match, this will never happen as the |
|
* ntfs_are_names_equal() call will have gotten a match but we |
|
* still treat it correctly. |
|
*/ |
|
goto found_it; |
|
} |
|
/* |
|
* We have finished with this index without success. Check for the |
|
* presence of a child node. |
|
*/ |
|
if (!(ie->flags & INDEX_ENTRY_NODE)) { |
|
/* No child node, return -ENOENT. */ |
|
err = -ENOENT; |
|
goto err_out; |
|
} /* Child node present, descend into it. */ |
|
/* Consistency check: Verify that an index allocation exists. */ |
|
if (!NInoIndexAllocPresent(dir_ni)) { |
|
ntfs_error(sb, "No index allocation attribute but index entry " |
|
"requires one. Directory inode 0x%lx is " |
|
"corrupt or driver bug.", dir_ni->mft_no); |
|
goto err_out; |
|
} |
|
/* Get the starting vcn of the index_block holding the child node. */ |
|
vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8); |
|
ia_mapping = VFS_I(dir_ni)->i_mapping; |
|
/* |
|
* We are done with the index root and the mft record. Release them, |
|
* otherwise we deadlock with ntfs_map_page(). |
|
*/ |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(dir_ni); |
|
m = NULL; |
|
ctx = NULL; |
|
descend_into_child_node: |
|
/* |
|
* Convert vcn to index into the index allocation attribute in units |
|
* of PAGE_SIZE and map the page cache page, reading it from |
|
* disk if necessary. |
|
*/ |
|
page = ntfs_map_page(ia_mapping, vcn << |
|
dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT); |
|
if (IS_ERR(page)) { |
|
ntfs_error(sb, "Failed to map directory index page, error %ld.", |
|
-PTR_ERR(page)); |
|
err = PTR_ERR(page); |
|
goto err_out; |
|
} |
|
lock_page(page); |
|
kaddr = (u8*)page_address(page); |
|
fast_descend_into_child_node: |
|
/* Get to the index allocation block. */ |
|
ia = (INDEX_ALLOCATION*)(kaddr + ((vcn << |
|
dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK)); |
|
/* Bounds checks. */ |
|
if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) { |
|
ntfs_error(sb, "Out of bounds check failed. Corrupt directory " |
|
"inode 0x%lx or driver bug.", dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* Catch multi sector transfer fixup errors. */ |
|
if (unlikely(!ntfs_is_indx_record(ia->magic))) { |
|
ntfs_error(sb, "Directory index record with vcn 0x%llx is " |
|
"corrupt. Corrupt inode 0x%lx. Run chkdsk.", |
|
(unsigned long long)vcn, dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
if (sle64_to_cpu(ia->index_block_vcn) != vcn) { |
|
ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " |
|
"different from expected VCN (0x%llx). " |
|
"Directory inode 0x%lx is corrupt or driver " |
|
"bug.", (unsigned long long) |
|
sle64_to_cpu(ia->index_block_vcn), |
|
(unsigned long long)vcn, dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
if (le32_to_cpu(ia->index.allocated_size) + 0x18 != |
|
dir_ni->itype.index.block_size) { |
|
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " |
|
"0x%lx has a size (%u) differing from the " |
|
"directory specified size (%u). Directory " |
|
"inode is corrupt or driver bug.", |
|
(unsigned long long)vcn, dir_ni->mft_no, |
|
le32_to_cpu(ia->index.allocated_size) + 0x18, |
|
dir_ni->itype.index.block_size); |
|
goto unm_err_out; |
|
} |
|
index_end = (u8*)ia + dir_ni->itype.index.block_size; |
|
if (index_end > kaddr + PAGE_SIZE) { |
|
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " |
|
"0x%lx crosses page boundary. Impossible! " |
|
"Cannot access! This is probably a bug in the " |
|
"driver.", (unsigned long long)vcn, |
|
dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); |
|
if (index_end > (u8*)ia + dir_ni->itype.index.block_size) { |
|
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " |
|
"inode 0x%lx exceeds maximum size.", |
|
(unsigned long long)vcn, dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* The first index entry. */ |
|
ie = (INDEX_ENTRY*)((u8*)&ia->index + |
|
le32_to_cpu(ia->index.entries_offset)); |
|
/* |
|
* Iterate similar to above big loop but applied to index buffer, thus |
|
* loop until we exceed valid memory (corruption case) or until we |
|
* reach the last entry. |
|
*/ |
|
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { |
|
/* Bounds check. */ |
|
if ((u8*)ie < (u8*)ia || (u8*)ie + |
|
sizeof(INDEX_ENTRY_HEADER) > index_end || |
|
(u8*)ie + le16_to_cpu(ie->key_length) > |
|
index_end) { |
|
ntfs_error(sb, "Index entry out of bounds in " |
|
"directory inode 0x%lx.", |
|
dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* |
|
* The last entry cannot contain a name. It can however contain |
|
* a pointer to a child node in the B+tree so we just break out. |
|
*/ |
|
if (ie->flags & INDEX_ENTRY_END) |
|
break; |
|
/* |
|
* If the current entry has a name type of POSIX, the name is |
|
* case sensitive and not otherwise. This has the effect of us |
|
* not being able to access any POSIX file names which collate |
|
* after the non-POSIX one when they only differ in case, but |
|
* anyone doing screwy stuff like that deserves to burn in |
|
* hell... Doing that kind of stuff on NT4 actually causes |
|
* corruption on the partition even when using SP6a and Linux |
|
* is not involved at all. |
|
*/ |
|
ic = ie->key.file_name.file_name_type ? IGNORE_CASE : |
|
CASE_SENSITIVE; |
|
/* |
|
* If the names match perfectly, we are done and return the |
|
* mft reference of the inode (i.e. the inode number together |
|
* with the sequence number for consistency checking. We |
|
* convert it to cpu format before returning. |
|
*/ |
|
if (ntfs_are_names_equal(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, ic, |
|
vol->upcase, vol->upcase_len)) { |
|
found_it2: |
|
mref = le64_to_cpu(ie->data.dir.indexed_file); |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
return mref; |
|
} |
|
/* |
|
* Not a perfect match, need to do full blown collation so we |
|
* know which way in the B+tree we have to go. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
IGNORE_CASE, vol->upcase, vol->upcase_len); |
|
/* |
|
* If uname collates before the name of the current entry, there |
|
* is definitely no such name in this index but we might need to |
|
* descend into the B+tree so we just break out of the loop. |
|
*/ |
|
if (rc == -1) |
|
break; |
|
/* The names are not equal, continue the search. */ |
|
if (rc) |
|
continue; |
|
/* |
|
* Names match with case insensitive comparison, now try the |
|
* case sensitive comparison, which is required for proper |
|
* collation. |
|
*/ |
|
rc = ntfs_collate_names(uname, uname_len, |
|
(ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, 1, |
|
CASE_SENSITIVE, vol->upcase, vol->upcase_len); |
|
if (rc == -1) |
|
break; |
|
if (rc) |
|
continue; |
|
/* |
|
* Perfect match, this will never happen as the |
|
* ntfs_are_names_equal() call will have gotten a match but we |
|
* still treat it correctly. |
|
*/ |
|
goto found_it2; |
|
} |
|
/* |
|
* We have finished with this index buffer without success. Check for |
|
* the presence of a child node. |
|
*/ |
|
if (ie->flags & INDEX_ENTRY_NODE) { |
|
if ((ia->index.flags & NODE_MASK) == LEAF_NODE) { |
|
ntfs_error(sb, "Index entry with child node found in " |
|
"a leaf node in directory inode 0x%lx.", |
|
dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* Child node present, descend into it. */ |
|
old_vcn = vcn; |
|
vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8); |
|
if (vcn >= 0) { |
|
/* If vcn is in the same page cache page as old_vcn we |
|
* recycle the mapped page. */ |
|
if (old_vcn << vol->cluster_size_bits >> |
|
PAGE_SHIFT == vcn << |
|
vol->cluster_size_bits >> |
|
PAGE_SHIFT) |
|
goto fast_descend_into_child_node; |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
goto descend_into_child_node; |
|
} |
|
ntfs_error(sb, "Negative child node vcn in directory inode " |
|
"0x%lx.", dir_ni->mft_no); |
|
goto unm_err_out; |
|
} |
|
/* No child node, return -ENOENT. */ |
|
ntfs_debug("Entry not found."); |
|
err = -ENOENT; |
|
unm_err_out: |
|
unlock_page(page); |
|
ntfs_unmap_page(page); |
|
err_out: |
|
if (!err) |
|
err = -EIO; |
|
if (ctx) |
|
ntfs_attr_put_search_ctx(ctx); |
|
if (m) |
|
unmap_mft_record(dir_ni); |
|
return ERR_MREF(err); |
|
dir_err_out: |
|
ntfs_error(sb, "Corrupt directory. Aborting lookup."); |
|
goto err_out; |
|
} |
|
|
|
#endif |
|
|
|
/** |
|
* ntfs_filldir - ntfs specific filldir method |
|
* @vol: current ntfs volume |
|
* @ndir: ntfs inode of current directory |
|
* @ia_page: page in which the index allocation buffer @ie is in resides |
|
* @ie: current index entry |
|
* @name: buffer to use for the converted name |
|
* @actor: what to feed the entries to |
|
* |
|
* Convert the Unicode @name to the loaded NLS and pass it to the @filldir |
|
* callback. |
|
* |
|
* If @ia_page is not NULL it is the locked page containing the index |
|
* allocation block containing the index entry @ie. |
|
* |
|
* Note, we drop (and then reacquire) the page lock on @ia_page across the |
|
* @filldir() call otherwise we would deadlock with NFSd when it calls ->lookup |
|
* since ntfs_lookup() will lock the same page. As an optimization, we do not |
|
* retake the lock if we are returning a non-zero value as ntfs_readdir() |
|
* would need to drop the lock immediately anyway. |
|
*/ |
|
static inline int ntfs_filldir(ntfs_volume *vol, |
|
ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie, |
|
u8 *name, struct dir_context *actor) |
|
{ |
|
unsigned long mref; |
|
int name_len; |
|
unsigned dt_type; |
|
FILE_NAME_TYPE_FLAGS name_type; |
|
|
|
name_type = ie->key.file_name.file_name_type; |
|
if (name_type == FILE_NAME_DOS) { |
|
ntfs_debug("Skipping DOS name space entry."); |
|
return 0; |
|
} |
|
if (MREF_LE(ie->data.dir.indexed_file) == FILE_root) { |
|
ntfs_debug("Skipping root directory self reference entry."); |
|
return 0; |
|
} |
|
if (MREF_LE(ie->data.dir.indexed_file) < FILE_first_user && |
|
!NVolShowSystemFiles(vol)) { |
|
ntfs_debug("Skipping system file."); |
|
return 0; |
|
} |
|
name_len = ntfs_ucstonls(vol, (ntfschar*)&ie->key.file_name.file_name, |
|
ie->key.file_name.file_name_length, &name, |
|
NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1); |
|
if (name_len <= 0) { |
|
ntfs_warning(vol->sb, "Skipping unrepresentable inode 0x%llx.", |
|
(long long)MREF_LE(ie->data.dir.indexed_file)); |
|
return 0; |
|
} |
|
if (ie->key.file_name.file_attributes & |
|
FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT) |
|
dt_type = DT_DIR; |
|
else |
|
dt_type = DT_REG; |
|
mref = MREF_LE(ie->data.dir.indexed_file); |
|
/* |
|
* Drop the page lock otherwise we deadlock with NFS when it calls |
|
* ->lookup since ntfs_lookup() will lock the same page. |
|
*/ |
|
if (ia_page) |
|
unlock_page(ia_page); |
|
ntfs_debug("Calling filldir for %s with len %i, fpos 0x%llx, inode " |
|
"0x%lx, DT_%s.", name, name_len, actor->pos, mref, |
|
dt_type == DT_DIR ? "DIR" : "REG"); |
|
if (!dir_emit(actor, name, name_len, mref, dt_type)) |
|
return 1; |
|
/* Relock the page but not if we are aborting ->readdir. */ |
|
if (ia_page) |
|
lock_page(ia_page); |
|
return 0; |
|
} |
|
|
|
/* |
|
* We use the same basic approach as the old NTFS driver, i.e. we parse the |
|
* index root entries and then the index allocation entries that are marked |
|
* as in use in the index bitmap. |
|
* |
|
* While this will return the names in random order this doesn't matter for |
|
* ->readdir but OTOH results in a faster ->readdir. |
|
* |
|
* VFS calls ->readdir without BKL but with i_mutex held. This protects the VFS |
|
* parts (e.g. ->f_pos and ->i_size, and it also protects against directory |
|
* modifications). |
|
* |
|
* Locking: - Caller must hold i_mutex on the directory. |
|
* - Each page cache page in the index allocation mapping must be |
|
* locked whilst being accessed otherwise we may find a corrupt |
|
* page due to it being under ->writepage at the moment which |
|
* applies the mst protection fixups before writing out and then |
|
* removes them again after the write is complete after which it |
|
* unlocks the page. |
|
*/ |
|
static int ntfs_readdir(struct file *file, struct dir_context *actor) |
|
{ |
|
s64 ia_pos, ia_start, prev_ia_pos, bmp_pos; |
|
loff_t i_size; |
|
struct inode *bmp_vi, *vdir = file_inode(file); |
|
struct super_block *sb = vdir->i_sb; |
|
ntfs_inode *ndir = NTFS_I(vdir); |
|
ntfs_volume *vol = NTFS_SB(sb); |
|
MFT_RECORD *m; |
|
INDEX_ROOT *ir = NULL; |
|
INDEX_ENTRY *ie; |
|
INDEX_ALLOCATION *ia; |
|
u8 *name = NULL; |
|
int rc, err, ir_pos, cur_bmp_pos; |
|
struct address_space *ia_mapping, *bmp_mapping; |
|
struct page *bmp_page = NULL, *ia_page = NULL; |
|
u8 *kaddr, *bmp, *index_end; |
|
ntfs_attr_search_ctx *ctx; |
|
|
|
ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.", |
|
vdir->i_ino, actor->pos); |
|
rc = err = 0; |
|
/* Are we at end of dir yet? */ |
|
i_size = i_size_read(vdir); |
|
if (actor->pos >= i_size + vol->mft_record_size) |
|
return 0; |
|
/* Emulate . and .. for all directories. */ |
|
if (!dir_emit_dots(file, actor)) |
|
return 0; |
|
m = NULL; |
|
ctx = NULL; |
|
/* |
|
* Allocate a buffer to store the current name being processed |
|
* converted to format determined by current NLS. |
|
*/ |
|
name = kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1, GFP_NOFS); |
|
if (unlikely(!name)) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
/* Are we jumping straight into the index allocation attribute? */ |
|
if (actor->pos >= vol->mft_record_size) |
|
goto skip_index_root; |
|
/* Get hold of the mft record for the directory. */ |
|
m = map_mft_record(ndir); |
|
if (IS_ERR(m)) { |
|
err = PTR_ERR(m); |
|
m = NULL; |
|
goto err_out; |
|
} |
|
ctx = ntfs_attr_get_search_ctx(ndir, m); |
|
if (unlikely(!ctx)) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
/* Get the offset into the index root attribute. */ |
|
ir_pos = (s64)actor->pos; |
|
/* Find the index root attribute in the mft record. */ |
|
err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, |
|
0, ctx); |
|
if (unlikely(err)) { |
|
ntfs_error(sb, "Index root attribute missing in directory " |
|
"inode 0x%lx.", vdir->i_ino); |
|
goto err_out; |
|
} |
|
/* |
|
* Copy the index root attribute value to a buffer so that we can put |
|
* the search context and unmap the mft record before calling the |
|
* filldir() callback. We need to do this because of NFSd which calls |
|
* ->lookup() from its filldir callback() and this causes NTFS to |
|
* deadlock as ntfs_lookup() maps the mft record of the directory and |
|
* we have got it mapped here already. The only solution is for us to |
|
* unmap the mft record here so that a call to ntfs_lookup() is able to |
|
* map the mft record without deadlocking. |
|
*/ |
|
rc = le32_to_cpu(ctx->attr->data.resident.value_length); |
|
ir = kmalloc(rc, GFP_NOFS); |
|
if (unlikely(!ir)) { |
|
err = -ENOMEM; |
|
goto err_out; |
|
} |
|
/* Copy the index root value (it has been verified in read_inode). */ |
|
memcpy(ir, (u8*)ctx->attr + |
|
le16_to_cpu(ctx->attr->data.resident.value_offset), rc); |
|
ntfs_attr_put_search_ctx(ctx); |
|
unmap_mft_record(ndir); |
|
ctx = NULL; |
|
m = NULL; |
|
index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); |
|
/* The first index entry. */ |
|
ie = (INDEX_ENTRY*)((u8*)&ir->index + |
|
le32_to_cpu(ir->index.entries_offset)); |
|
/* |
|
* Loop until we exceed valid memory (corruption case) or until we |
|
* reach the last entry or until filldir tells us it has had enough |
|
* or signals an error (both covered by the rc test). |
|
*/ |
|
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { |
|
ntfs_debug("In index root, offset 0x%zx.", (u8*)ie - (u8*)ir); |
|
/* Bounds checks. */ |
|
if (unlikely((u8*)ie < (u8*)ir || (u8*)ie + |
|
sizeof(INDEX_ENTRY_HEADER) > index_end || |
|
(u8*)ie + le16_to_cpu(ie->key_length) > |
|
index_end)) |
|
goto err_out; |
|
/* The last entry cannot contain a name. */ |
|
if (ie->flags & INDEX_ENTRY_END) |
|
break; |
|
/* Skip index root entry if continuing previous readdir. */ |
|
if (ir_pos > (u8*)ie - (u8*)ir) |
|
continue; |
|
/* Advance the position even if going to skip the entry. */ |
|
actor->pos = (u8*)ie - (u8*)ir; |
|
/* Submit the name to the filldir callback. */ |
|
rc = ntfs_filldir(vol, ndir, NULL, ie, name, actor); |
|
if (rc) { |
|
kfree(ir); |
|
goto abort; |
|
} |
|
} |
|
/* We are done with the index root and can free the buffer. */ |
|
kfree(ir); |
|
ir = NULL; |
|
/* If there is no index allocation attribute we are finished. */ |
|
if (!NInoIndexAllocPresent(ndir)) |
|
goto EOD; |
|
/* Advance fpos to the beginning of the index allocation. */ |
|
actor->pos = vol->mft_record_size; |
|
skip_index_root: |
|
kaddr = NULL; |
|
prev_ia_pos = -1LL; |
|
/* Get the offset into the index allocation attribute. */ |
|
ia_pos = (s64)actor->pos - vol->mft_record_size; |
|
ia_mapping = vdir->i_mapping; |
|
ntfs_debug("Inode 0x%lx, getting index bitmap.", vdir->i_ino); |
|
bmp_vi = ntfs_attr_iget(vdir, AT_BITMAP, I30, 4); |
|
if (IS_ERR(bmp_vi)) { |
|
ntfs_error(sb, "Failed to get bitmap attribute."); |
|
err = PTR_ERR(bmp_vi); |
|
goto err_out; |
|
} |
|
bmp_mapping = bmp_vi->i_mapping; |
|
/* Get the starting bitmap bit position and sanity check it. */ |
|
bmp_pos = ia_pos >> ndir->itype.index.block_size_bits; |
|
if (unlikely(bmp_pos >> 3 >= i_size_read(bmp_vi))) { |
|
ntfs_error(sb, "Current index allocation position exceeds " |
|
"index bitmap size."); |
|
goto iput_err_out; |
|
} |
|
/* Get the starting bit position in the current bitmap page. */ |
|
cur_bmp_pos = bmp_pos & ((PAGE_SIZE * 8) - 1); |
|
bmp_pos &= ~(u64)((PAGE_SIZE * 8) - 1); |
|
get_next_bmp_page: |
|
ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx", |
|
(unsigned long long)bmp_pos >> (3 + PAGE_SHIFT), |
|
(unsigned long long)bmp_pos & |
|
(unsigned long long)((PAGE_SIZE * 8) - 1)); |
|
bmp_page = ntfs_map_page(bmp_mapping, |
|
bmp_pos >> (3 + PAGE_SHIFT)); |
|
if (IS_ERR(bmp_page)) { |
|
ntfs_error(sb, "Reading index bitmap failed."); |
|
err = PTR_ERR(bmp_page); |
|
bmp_page = NULL; |
|
goto iput_err_out; |
|
} |
|
bmp = (u8*)page_address(bmp_page); |
|
/* Find next index block in use. */ |
|
while (!(bmp[cur_bmp_pos >> 3] & (1 << (cur_bmp_pos & 7)))) { |
|
find_next_index_buffer: |
|
cur_bmp_pos++; |
|
/* |
|
* If we have reached the end of the bitmap page, get the next |
|
* page, and put away the old one. |
|
*/ |
|
if (unlikely((cur_bmp_pos >> 3) >= PAGE_SIZE)) { |
|
ntfs_unmap_page(bmp_page); |
|
bmp_pos += PAGE_SIZE * 8; |
|
cur_bmp_pos = 0; |
|
goto get_next_bmp_page; |
|
} |
|
/* If we have reached the end of the bitmap, we are done. */ |
|
if (unlikely(((bmp_pos + cur_bmp_pos) >> 3) >= i_size)) |
|
goto unm_EOD; |
|
ia_pos = (bmp_pos + cur_bmp_pos) << |
|
ndir->itype.index.block_size_bits; |
|
} |
|
ntfs_debug("Handling index buffer 0x%llx.", |
|
(unsigned long long)bmp_pos + cur_bmp_pos); |
|
/* If the current index buffer is in the same page we reuse the page. */ |
|
if ((prev_ia_pos & (s64)PAGE_MASK) != |
|
(ia_pos & (s64)PAGE_MASK)) { |
|
prev_ia_pos = ia_pos; |
|
if (likely(ia_page != NULL)) { |
|
unlock_page(ia_page); |
|
ntfs_unmap_page(ia_page); |
|
} |
|
/* |
|
* Map the page cache page containing the current ia_pos, |
|
* reading it from disk if necessary. |
|
*/ |
|
ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_SHIFT); |
|
if (IS_ERR(ia_page)) { |
|
ntfs_error(sb, "Reading index allocation data failed."); |
|
err = PTR_ERR(ia_page); |
|
ia_page = NULL; |
|
goto err_out; |
|
} |
|
lock_page(ia_page); |
|
kaddr = (u8*)page_address(ia_page); |
|
} |
|
/* Get the current index buffer. */ |
|
ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_MASK & |
|
~(s64)(ndir->itype.index.block_size - 1))); |
|
/* Bounds checks. */ |
|
if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE)) { |
|
ntfs_error(sb, "Out of bounds check failed. Corrupt directory " |
|
"inode 0x%lx or driver bug.", vdir->i_ino); |
|
goto err_out; |
|
} |
|
/* Catch multi sector transfer fixup errors. */ |
|
if (unlikely(!ntfs_is_indx_record(ia->magic))) { |
|
ntfs_error(sb, "Directory index record with vcn 0x%llx is " |
|
"corrupt. Corrupt inode 0x%lx. Run chkdsk.", |
|
(unsigned long long)ia_pos >> |
|
ndir->itype.index.vcn_size_bits, vdir->i_ino); |
|
goto err_out; |
|
} |
|
if (unlikely(sle64_to_cpu(ia->index_block_vcn) != (ia_pos & |
|
~(s64)(ndir->itype.index.block_size - 1)) >> |
|
ndir->itype.index.vcn_size_bits)) { |
|
ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " |
|
"different from expected VCN (0x%llx). " |
|
"Directory inode 0x%lx is corrupt or driver " |
|
"bug. ", (unsigned long long) |
|
sle64_to_cpu(ia->index_block_vcn), |
|
(unsigned long long)ia_pos >> |
|
ndir->itype.index.vcn_size_bits, vdir->i_ino); |
|
goto err_out; |
|
} |
|
if (unlikely(le32_to_cpu(ia->index.allocated_size) + 0x18 != |
|
ndir->itype.index.block_size)) { |
|
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " |
|
"0x%lx has a size (%u) differing from the " |
|
"directory specified size (%u). Directory " |
|
"inode is corrupt or driver bug.", |
|
(unsigned long long)ia_pos >> |
|
ndir->itype.index.vcn_size_bits, vdir->i_ino, |
|
le32_to_cpu(ia->index.allocated_size) + 0x18, |
|
ndir->itype.index.block_size); |
|
goto err_out; |
|
} |
|
index_end = (u8*)ia + ndir->itype.index.block_size; |
|
if (unlikely(index_end > kaddr + PAGE_SIZE)) { |
|
ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " |
|
"0x%lx crosses page boundary. Impossible! " |
|
"Cannot access! This is probably a bug in the " |
|
"driver.", (unsigned long long)ia_pos >> |
|
ndir->itype.index.vcn_size_bits, vdir->i_ino); |
|
goto err_out; |
|
} |
|
ia_start = ia_pos & ~(s64)(ndir->itype.index.block_size - 1); |
|
index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); |
|
if (unlikely(index_end > (u8*)ia + ndir->itype.index.block_size)) { |
|
ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " |
|
"inode 0x%lx exceeds maximum size.", |
|
(unsigned long long)ia_pos >> |
|
ndir->itype.index.vcn_size_bits, vdir->i_ino); |
|
goto err_out; |
|
} |
|
/* The first index entry in this index buffer. */ |
|
ie = (INDEX_ENTRY*)((u8*)&ia->index + |
|
le32_to_cpu(ia->index.entries_offset)); |
|
/* |
|
* Loop until we exceed valid memory (corruption case) or until we |
|
* reach the last entry or until filldir tells us it has had enough |
|
* or signals an error (both covered by the rc test). |
|
*/ |
|
for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { |
|
ntfs_debug("In index allocation, offset 0x%llx.", |
|
(unsigned long long)ia_start + |
|
(unsigned long long)((u8*)ie - (u8*)ia)); |
|
/* Bounds checks. */ |
|
if (unlikely((u8*)ie < (u8*)ia || (u8*)ie + |
|
sizeof(INDEX_ENTRY_HEADER) > index_end || |
|
(u8*)ie + le16_to_cpu(ie->key_length) > |
|
index_end)) |
|
goto err_out; |
|
/* The last entry cannot contain a name. */ |
|
if (ie->flags & INDEX_ENTRY_END) |
|
break; |
|
/* Skip index block entry if continuing previous readdir. */ |
|
if (ia_pos - ia_start > (u8*)ie - (u8*)ia) |
|
continue; |
|
/* Advance the position even if going to skip the entry. */ |
|
actor->pos = (u8*)ie - (u8*)ia + |
|
(sle64_to_cpu(ia->index_block_vcn) << |
|
ndir->itype.index.vcn_size_bits) + |
|
vol->mft_record_size; |
|
/* |
|
* Submit the name to the @filldir callback. Note, |
|
* ntfs_filldir() drops the lock on @ia_page but it retakes it |
|
* before returning, unless a non-zero value is returned in |
|
* which case the page is left unlocked. |
|
*/ |
|
rc = ntfs_filldir(vol, ndir, ia_page, ie, name, actor); |
|
if (rc) { |
|
/* @ia_page is already unlocked in this case. */ |
|
ntfs_unmap_page(ia_page); |
|
ntfs_unmap_page(bmp_page); |
|
iput(bmp_vi); |
|
goto abort; |
|
} |
|
} |
|
goto find_next_index_buffer; |
|
unm_EOD: |
|
if (ia_page) { |
|
unlock_page(ia_page); |
|
ntfs_unmap_page(ia_page); |
|
} |
|
ntfs_unmap_page(bmp_page); |
|
iput(bmp_vi); |
|
EOD: |
|
/* We are finished, set fpos to EOD. */ |
|
actor->pos = i_size + vol->mft_record_size; |
|
abort: |
|
kfree(name); |
|
return 0; |
|
err_out: |
|
if (bmp_page) { |
|
ntfs_unmap_page(bmp_page); |
|
iput_err_out: |
|
iput(bmp_vi); |
|
} |
|
if (ia_page) { |
|
unlock_page(ia_page); |
|
ntfs_unmap_page(ia_page); |
|
} |
|
kfree(ir); |
|
kfree(name); |
|
if (ctx) |
|
ntfs_attr_put_search_ctx(ctx); |
|
if (m) |
|
unmap_mft_record(ndir); |
|
if (!err) |
|
err = -EIO; |
|
ntfs_debug("Failed. Returning error code %i.", -err); |
|
return err; |
|
} |
|
|
|
/** |
|
* ntfs_dir_open - called when an inode is about to be opened |
|
* @vi: inode to be opened |
|
* @filp: file structure describing the inode |
|
* |
|
* Limit directory size to the page cache limit on architectures where unsigned |
|
* long is 32-bits. This is the most we can do for now without overflowing the |
|
* page cache page index. Doing it this way means we don't run into problems |
|
* because of existing too large directories. It would be better to allow the |
|
* user to read the accessible part of the directory but I doubt very much |
|
* anyone is going to hit this check on a 32-bit architecture, so there is no |
|
* point in adding the extra complexity required to support this. |
|
* |
|
* On 64-bit architectures, the check is hopefully optimized away by the |
|
* compiler. |
|
*/ |
|
static int ntfs_dir_open(struct inode *vi, struct file *filp) |
|
{ |
|
if (sizeof(unsigned long) < 8) { |
|
if (i_size_read(vi) > MAX_LFS_FILESIZE) |
|
return -EFBIG; |
|
} |
|
return 0; |
|
} |
|
|
|
#ifdef NTFS_RW |
|
|
|
/** |
|
* ntfs_dir_fsync - sync a directory to disk |
|
* @filp: directory to be synced |
|
* @dentry: dentry describing the directory to sync |
|
* @datasync: if non-zero only flush user data and not metadata |
|
* |
|
* Data integrity sync of a directory to disk. Used for fsync, fdatasync, and |
|
* msync system calls. This function is based on file.c::ntfs_file_fsync(). |
|
* |
|
* Write the mft record and all associated extent mft records as well as the |
|
* $INDEX_ALLOCATION and $BITMAP attributes and then sync the block device. |
|
* |
|
* If @datasync is true, we do not wait on the inode(s) to be written out |
|
* but we always wait on the page cache pages to be written out. |
|
* |
|
* Note: In the past @filp could be NULL so we ignore it as we don't need it |
|
* anyway. |
|
* |
|
* Locking: Caller must hold i_mutex on the inode. |
|
* |
|
* TODO: We should probably also write all attribute/index inodes associated |
|
* with this inode but since we have no simple way of getting to them we ignore |
|
* this problem for now. We do write the $BITMAP attribute if it is present |
|
* which is the important one for a directory so things are not too bad. |
|
*/ |
|
static int ntfs_dir_fsync(struct file *filp, loff_t start, loff_t end, |
|
int datasync) |
|
{ |
|
struct inode *bmp_vi, *vi = filp->f_mapping->host; |
|
int err, ret; |
|
ntfs_attr na; |
|
|
|
ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); |
|
|
|
err = file_write_and_wait_range(filp, start, end); |
|
if (err) |
|
return err; |
|
inode_lock(vi); |
|
|
|
BUG_ON(!S_ISDIR(vi->i_mode)); |
|
/* If the bitmap attribute inode is in memory sync it, too. */ |
|
na.mft_no = vi->i_ino; |
|
na.type = AT_BITMAP; |
|
na.name = I30; |
|
na.name_len = 4; |
|
bmp_vi = ilookup5(vi->i_sb, vi->i_ino, ntfs_test_inode, &na); |
|
if (bmp_vi) { |
|
write_inode_now(bmp_vi, !datasync); |
|
iput(bmp_vi); |
|
} |
|
ret = __ntfs_write_inode(vi, 1); |
|
write_inode_now(vi, !datasync); |
|
err = sync_blockdev(vi->i_sb->s_bdev); |
|
if (unlikely(err && !ret)) |
|
ret = err; |
|
if (likely(!ret)) |
|
ntfs_debug("Done."); |
|
else |
|
ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " |
|
"%u.", datasync ? "data" : "", vi->i_ino, -ret); |
|
inode_unlock(vi); |
|
return ret; |
|
} |
|
|
|
#endif /* NTFS_RW */ |
|
|
|
const struct file_operations ntfs_dir_ops = { |
|
.llseek = generic_file_llseek, /* Seek inside directory. */ |
|
.read = generic_read_dir, /* Return -EISDIR. */ |
|
.iterate = ntfs_readdir, /* Read directory contents. */ |
|
#ifdef NTFS_RW |
|
.fsync = ntfs_dir_fsync, /* Sync a directory to disk. */ |
|
#endif /* NTFS_RW */ |
|
/*.ioctl = ,*/ /* Perform function on the |
|
mounted filesystem. */ |
|
.open = ntfs_dir_open, /* Open directory. */ |
|
};
|
|
|