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Use pm_fatlock to protect per-filesystem rb tree used to allocate fileno

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on the large FAT volumes. Previously, a single global mutex was used.

Tested by:	pho
MFC after:	3 weeks
This commit is contained in:
Konstantin Belousov 2010-02-28 17:16:43 +00:00
parent eb739c7cd5
commit 30e65ad1bb
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=204473
1 changed files with 6 additions and 10 deletions
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16
sys/fs/msdosfs/msdosfs_fileno.c
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@ -51,7 +51,6 @@ __FBSDID("$FreeBSD$");
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <fs/msdosfs/bpb.h>
#include <fs/msdosfs/direntry.h>
@ -59,9 +58,6 @@ __FBSDID("$FreeBSD$");
static MALLOC_DEFINE(M_MSDOSFSFILENO, "msdosfs_fileno", "MSDOSFS fileno mapping node");
static struct mtx fileno_mtx;
MTX_SYSINIT(fileno, &fileno_mtx, "MSDOSFS fileno", MTX_DEF);
RB_PROTOTYPE(msdosfs_filenotree, msdosfs_fileno, mf_tree,
msdosfs_fileno_compare)
@ -117,30 +113,30 @@ msdosfs_fileno_map(mp, fileno)
}
if (fileno < FILENO_FIRST_DYN)
return ((uint32_t)fileno);
mtx_lock(&fileno_mtx);
MSDOSFS_LOCK_MP(pmp);
key.mf_fileno64 = fileno;
mf = RB_FIND(msdosfs_filenotree, &pmp->pm_filenos, &key);
if (mf != NULL) {
mapped = mf->mf_fileno32;
mtx_unlock(&fileno_mtx);
MSDOSFS_UNLOCK_MP(pmp);
return (mapped);
}
if (pmp->pm_nfileno < FILENO_FIRST_DYN)
panic("msdosfs_fileno_map: wraparound");
mtx_unlock(&fileno_mtx);
MSDOSFS_UNLOCK_MP(pmp);
mf = malloc(sizeof(*mf), M_MSDOSFSFILENO, M_WAITOK);
mtx_lock(&fileno_mtx);
MSDOSFS_LOCK_MP(pmp);
tmf = RB_FIND(msdosfs_filenotree, &pmp->pm_filenos, &key);
if (tmf != NULL) {
mapped = tmf->mf_fileno32;
mtx_unlock(&fileno_mtx);
MSDOSFS_UNLOCK_MP(pmp);
free(mf, M_MSDOSFSFILENO);
return (mapped);
}
mf->mf_fileno64 = fileno;
mapped = mf->mf_fileno32 = pmp->pm_nfileno++;
RB_INSERT(msdosfs_filenotree, &pmp->pm_filenos, mf);
mtx_unlock(&fileno_mtx);
MSDOSFS_UNLOCK_MP(pmp);
return (mapped);
}