From 271849a98849394ea85fa7caa8a1aaa2b3a849b7 Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov Date: Mon, 7 Mar 2005 21:36:18 +0000 Subject: NTFS: Add fs/ntfs/attrib.[hc]::ntfs_attr_vcn_to_lcn_nolock() used by the new write code. Signed-off-by: Anton Altaparmakov --- fs/ntfs/ChangeLog | 6 ++-- fs/ntfs/attrib.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/ntfs/attrib.h | 5 +++- 3 files changed, 95 insertions(+), 3 deletions(-) diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog index 868871cb9c6..4af6ae6ff12 100644 --- a/fs/ntfs/ChangeLog +++ b/fs/ntfs/ChangeLog @@ -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. diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index fa464fce226..1610f1cd286 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -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 diff --git a/fs/ntfs/attrib.h b/fs/ntfs/attrib.h index 3eb45165702..75041c89c73 100644 --- a/fs/ntfs/attrib.h +++ b/fs/ntfs/attrib.h @@ -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); -- cgit v1.2.3