Commit 271849a9 authored by Anton Altaparmakov's avatar Anton Altaparmakov

NTFS: Add fs/ntfs/attrib.[hc]::ntfs_attr_vcn_to_lcn_nolock() used by the new

      write code.
Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
parent 7e693073
......@@ -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.
......
......@@ -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
......
......@@ -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);
......
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