NTFS: Change ntfs_map_runlist_nolock() to also take an optional attribute (fd9d6367) · Commits · e / devices / android_kernel_fairphone_FP3

fs/ntfs/ChangeLog

+5 −0

Original line number	Diff line number	Diff line
		@@ -22,6 +22,11 @@ ToDo/Notes:
		- Enable the code for setting the NT4 compatibility flag when we start
		making NTFS 1.2 specific modifications.

		2.1.25-WIP

		- Change ntfs_map_runlist_nolock() to also take an optional attribute
		search context. This allows calling it with the mft record mapped.

		2.1.24 - Lots of bug fixes and support more clean journal states.

		- Support journals ($LogFile) which have been modified by chkdsk. This

fs/ntfs/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -6,7 +6,7 @@ ntfs-objs := aops.o attrib.o collate.o compress.o debug.o dir.o file.o \
		index.o inode.o mft.o mst.o namei.o runlist.o super.o sysctl.o \
		unistr.o upcase.o

		EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.24\"
		EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.25-WIP\"

		ifeq ($(CONFIG_NTFS_DEBUG),y)
		EXTRA_CFLAGS += -DDEBUG

fs/ntfs/attrib.c

+201 −31

Original line number	Diff line number	Diff line
		@@ -36,9 +36,27 @@
		* 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.
		@@ -46,19 +64,32 @@
		* 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.
		*
		* Locking: - The runlist must be locked for writing.
		* - This function modifies the 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)
		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;
		ntfs_attr_search_ctx *ctx;
		runlist_element *rl;
		unsigned long flags;
		struct page *put_this_page = NULL;
		int err = 0;
		BOOL ctx_is_temporary, ctx_needs_reset;
		ntfs_attr_search_ctx old_ctx;

		ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
		(unsigned long long)vcn);
		@@ -66,6 +97,8 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
		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);
		@@ -74,6 +107,59 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
		err = -ENOMEM;
		goto err_out;
		}
		} else {
		VCN allocated_size_vcn;

		BUG_ON(IS_ERR(ctx->mrec));
		a = ctx->attr;
		BUG_ON(!a->non_resident);
		ctx_is_temporary = FALSE;
		end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
		read_lock_irqsave(&ni->size_lock, flags);
		allocated_size_vcn = ni->allocated_size >>
		ni->vol->cluster_size_bits;
		read_unlock_irqrestore(&ni->size_lock, flags);
		if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
		end_vcn = allocated_size_vcn - 1;
		/*
		* If we already have the attribute extent containing @vcn in
		* @ctx, no need to look it up again. We slightly cheat in
		* that if vcn exceeds the allocated size, we will refuse to
		* map the runlist below, so there is definitely no need to get
		* the right attribute extent.
		*/
		if (vcn >= allocated_size_vcn \|\| (a->type == ni->type &&
		a->name_length == ni->name_len &&
		!memcmp((u8*)a + le16_to_cpu(a->name_offset),
		ni->name, ni->name_len) &&
		sle64_to_cpu(a->data.non_resident.lowest_vcn)
		<= vcn && end_vcn >= vcn))
		ctx_needs_reset = FALSE;
		else {
		/* Save the old search context. */
		old_ctx = *ctx;
		/*
		* If the currently mapped (extent) inode is not the
		* base inode we will unmap it when we reinitialize the
		* search context which means we need to get a
		* reference to the page containing the mapped mft
		* record so we do not accidentally drop changes to the
		* mft record when it has not been marked dirty yet.
		*/
		if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
		old_ctx.base_ntfs_ino) {
		put_this_page = old_ctx.ntfs_ino->page;
		page_cache_get(put_this_page);
		}
		/*
		* Reinitialize the search context so we can lookup the
		* needed attribute extent.
		*/
		ntfs_attr_reinit_search_ctx(ctx);
		ctx_needs_reset = TRUE;
		}
		}
		if (ctx_needs_reset) {
		err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
		CASE_SENSITIVE, vcn, NULL, 0, ctx);
		if (unlikely(err)) {
		@@ -81,6 +167,8 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
		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
		@@ -89,11 +177,9 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
		* ntfs_mapping_pairs_decompress() fails.
		*/
		end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
		if (unlikely(!a->data.non_resident.lowest_vcn && end_vcn <= 1)) {
		read_lock_irqsave(&ni->size_lock, flags);
		end_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 == 1)
		end_vcn = sle64_to_cpu(a->data.non_resident.allocated_size) >>
		ni->vol->cluster_size_bits;
		if (unlikely(vcn >= end_vcn)) {
		err = -ENOENT;
		goto err_out;
		@@ -104,9 +190,93 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
		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 acomplished simply by copying the saved context back over
		* the caller supplied context. If there is an attribute list,
		* things are more complicated as we need to deal with mapping
		* of mft records and resulting potential changes in pointers.
		*/
		if (NInoAttrList(base_ni)) {
		/*
		* If the currently mapped (extent) inode is not the
		* one we had before, we need to unmap it and map the
		* old one.
		*/
		if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
		/*
		* If the currently mapped inode is not the
		* base inode, unmap it.
		*/
		if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
		ctx->base_ntfs_ino) {
		unmap_extent_mft_record(ctx->ntfs_ino);
		ctx->mrec = ctx->base_mrec;
		BUG_ON(!ctx->mrec);
		}
		/*
		* If the old mapped inode is not the base
		* inode, map it.
		*/
		if (old_ctx.base_ntfs_ino &&
		old_ctx.ntfs_ino !=
		old_ctx.base_ntfs_ino) {
		retry_map:
		ctx->mrec = map_mft_record(
		old_ctx.ntfs_ino);
		/*
		* Something bad has happened. If out
		* of memory retry till it succeeds.
		* Any other errors are fatal and we
		* return the error code in ctx->mrec.
		* Let the caller deal with it... We
		* just need to fudge things so the
		* caller can reinit and/or put the
		* search context safely.
		*/
		if (IS_ERR(ctx->mrec)) {
		if (PTR_ERR(ctx->mrec) ==
		-ENOMEM) {
		schedule();
		goto retry_map;
		} else
		old_ctx.ntfs_ino =
		old_ctx.
		base_ntfs_ino;
		}
		}
		}
		/* Update the changed pointers in the saved context. */
		if (ctx->mrec != old_ctx.mrec) {
		if (!IS_ERR(ctx->mrec))
		old_ctx.attr = (ATTR_RECORD*)(
		(u8*)ctx->mrec +
		((u8*)old_ctx.attr -
		(u8*)old_ctx.mrec));
		old_ctx.mrec = ctx->mrec;
		}
		}
		/* Restore the search context to the saved one. */
		*ctx = old_ctx;
		/*
		* We drop the reference on the page we took earlier. In the
		* case that IS_ERR(ctx->mrec) is true this means we might lose
		* some changes to the mft record that had been made between
		* the last time it was marked dirty/written out and now. This
		* at this stage is not a problem as the mapping error is fatal
		* enough that the mft record cannot be written out anyway and
		* the caller is very likely to shutdown the whole inode
		* immediately and mark the volume dirty for chkdsk to pick up
		* the pieces anyway.
		*/
		if (put_this_page)
		page_cache_release(put_this_page);
		}
		return err;
		}

		@@ -122,8 +292,8 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn)
		* 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 modifies the
		* runlist.
		* - This function takes the runlist lock for writing and may modify
		* the runlist.
		*/
		int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
		{
		@@ -133,7 +303,7 @@ int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
		/* 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);
		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
		up_write(&ni->runlist.lock);
		return err;
		}
		@@ -212,7 +382,7 @@ LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
		goto retry_remap;
		}
		}
		err = ntfs_map_runlist_nolock(ni, vcn);
		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
		if (!write_locked) {
		up_write(&ni->runlist.lock);
		down_read(&ni->runlist.lock);
		@@ -325,7 +495,7 @@ runlist_element ntfs_attr_find_vcn_nolock(ntfs_inode ni, const VCN vcn,
		goto retry_remap;
		}
		}
		err = ntfs_map_runlist_nolock(ni, vcn);
		err = ntfs_map_runlist_nolock(ni, vcn, NULL);
		if (!write_locked) {
		up_write(&ni->runlist.lock);
		down_read(&ni->runlist.lock);

fs/ntfs/attrib.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -60,7 +60,8 @@ typedef struct {
		ATTR_RECORD *base_attr;
		} ntfs_attr_search_ctx;

		extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn);
		extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn,
		ntfs_attr_search_ctx *ctx);
		extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn);

		extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,