lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

NTFS: - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after

Browse Source 
dropping the read lock and taking the write lock we were not checking
        whether someone else did not already do the work we wanted to do.
      - Rename ntfs_find_vcn_nolock() to ntfs_attr_find_vcn_nolock().
      - Tidy up some comments in fs/ntfs/runlist.c.
      - Add LCN_ENOMEM and LCN_EIO definitions to fs/ntfs/runlist.h.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
This commit is contained in:
Anton Altaparmakov
2005-03-07 21:43:38 +00:00
parent 271849a988
commit c0c1cc0e46
7 changed files with 39 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
fs/ntfs/attrib.c
View File

@ -193,19 +193,19 @@ retry_remap:
}
/**
* ntfs_find_vcn_nolock - find a vcn in the runlist described by an ntfs inode
* ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode
* @ni: ntfs inode describing the runlist to search
* @vcn: vcn to find
* @write_locked: true if the runlist is locked for writing
*
* Find the virtual cluster number @vcn in the runlist described by the ntfs
* inode @ni and return the address of the runlist element containing the @vcn.
* The runlist is left locked and the caller has to unlock it. In the error
* case, the runlist is left in the same locking state as on entry.
*
* Note if @write_locked is FALSE the lock may be dropped inside the function
* so you cannot rely on the runlist still being the same when this function
* returns.
* 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.
*
* Note you need to distinguish between the lcn of the returned runlist element
* being >= 0 and LCN_HOLE. In the later case you have to return zeroes on
@ -221,13 +221,12 @@ retry_remap:
* -ENOMEM - Not enough memory to map runlist.
* -EIO - Critical error (runlist/file is corrupt, i/o error, etc).
*
* Locking: - The runlist must be unlocked on entry.
* - On failing return, the runlist is unlocked.
* - On successful return, the runlist is locked. If @need_write us
* true, it is locked for writing. Otherwise is is locked for
* reading.
* 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.
*/
runlist_element *ntfs_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
const BOOL write_locked)
{
runlist_element *rl;
@ -268,6 +267,12 @@ retry_remap:
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) {