NTFS: Add fs/ntfs/attrib.[hc]::ntfs_attr_vcn_to_lcn_nolock() used by the new (271849a9) · Commits · e / devices / android_kernel_oneplus_sm8150

fs/ntfs/ChangeLog

+4 −2

Original line number	Diff line number	Diff line
		@@ -88,8 +88,10 @@ ToDo/Notes:
		checked and set in the ntfs inode as done for compressed files and
		the compressed size needs to be used for vfs inode->i_blocks instead
		of the allocated size, again, as done for compressed files.
		- Add AT_EA in addition to AT_DATA to whitelist for being allowed to
		be non-resident in fs/ntfs/attrib.c::ntfs_attr_can_be_non_resident().
		- Add AT_EA in addition to AT_DATA to whitelist for being allowed to be
		non-resident in fs/ntfs/attrib.c::ntfs_attr_can_be_non_resident().
		- Add fs/ntfs/attrib.c::ntfs_attr_vcn_to_lcn_nolock() used by the new
		write code.

		2.1.22 - Many bug and race fixes and error handling improvements.

fs/ntfs/attrib.c

+87 −0

Original line number	Diff line number	Diff line
		@@ -105,6 +105,93 @@ int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
		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;
		BOOL is_retry = FALSE;

		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(!ni);
		BUG_ON(!NInoNonResident(ni));
		BUG_ON(vcn < 0);
		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);
		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_find_vcn_nolock - find a vcn in the runlist described by an ntfs inode
		* @ni: ntfs inode describing the runlist to search

fs/ntfs/attrib.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -2,7 +2,7 @@
		* attrib.h - Defines for attribute handling in NTFS Linux kernel driver.
		* Part of the Linux-NTFS project.
		*
		* Copyright (c) 2001-2004 Anton Altaparmakov
		* Copyright (c) 2001-2005 Anton Altaparmakov
		* Copyright (c) 2002 Richard Russon
		*
		* This program/include file is free software; you can redistribute it and/or
		@@ -63,6 +63,9 @@ typedef struct {
		extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn);
		extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn);

		extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
		const BOOL write_locked);

		extern runlist_element ntfs_find_vcn_nolock(ntfs_inode ni, const VCN vcn,
		const BOOL write_locked);