From a3d7ab968438f4ef3440fdc4986fe5416a28e3cf Mon Sep 17 00:00:00 2001 From: Anand Avati Date: Sat, 27 Apr 2013 21:40:19 -0700 Subject: gfapi: optimistic resolution with ESTALE detection Enhance the path resolver to be optimistic. Instead of performing a wasteful ->lookup() fop for every component in every API call, build in speculation logic to consider the previous resolution result temporarily, and if it results in ESTALE either later in the path resolution or in the FOP, then retry resolution with ->lookup() at every level and retry the FOP. This is the same optimistic resolution/retry logic Linux kernel resolver is proposing to use. Change-Id: Iecbc25248754caf0915cd7205910563ff88ce5e7 BUG: 953694 Signed-off-by: Anand Avati Reviewed-on: http://review.gluster.org/5159 Tested-by: Gluster Build System Reviewed-by: Vijay Bellur --- api/src/glfs-resolve.c | 67 +++++++++++++++++++++++++++++++------------------- 1 file changed, 42 insertions(+), 25 deletions(-) (limited to 'api/src/glfs-resolve.c') diff --git a/api/src/glfs-resolve.c b/api/src/glfs-resolve.c index 17cf19d0fdc..07fc1b7c56a 100644 --- a/api/src/glfs-resolve.c +++ b/api/src/glfs-resolve.c @@ -136,7 +136,8 @@ out: inode_t * glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, - const char *component, struct iatt *iatt) + const char *component, struct iatt *iatt, + int force_lookup) { loc_t loc = {0, }; inode_t *inode = NULL; @@ -152,17 +153,6 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, loc.parent = inode_ref (parent); uuid_copy (loc.pargfid, parent->gfid); - xattr_req = dict_new (); - if (!xattr_req) { - errno = ENOMEM; - goto out; - } - - ret = dict_set_static_bin (xattr_req, "gfid-req", gfid, 16); - if (ret) { - errno = ENOMEM; - goto out; - } if (strcmp (component, ".") == 0) loc.inode = inode_ref (parent); @@ -174,6 +164,12 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, if (loc.inode) { uuid_copy (loc.gfid, loc.inode->gfid); reval = 1; + + if (!force_lookup) { + inode = inode_ref (loc.inode); + ciatt.ia_type = inode->ia_type; + goto found; + } } else { uuid_generate (gfid); loc.inode = inode_new (parent->table); @@ -182,20 +178,35 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, if (!loc.inode) goto out; - glret = glfs_loc_touchup (&loc); if (glret < 0) { ret = -1; goto out; } - ret = syncop_lookup (subvol, &loc, xattr_req, &ciatt, NULL, NULL); + ret = syncop_lookup (subvol, &loc, NULL, &ciatt, NULL, NULL); if (ret && reval) { inode_unref (loc.inode); loc.inode = inode_new (parent->table); - if (!loc.inode) + if (!loc.inode) { + errno = ENOMEM; goto out; + } + + xattr_req = dict_new (); + if (!xattr_req) { + errno = ENOMEM; + goto out; + } + uuid_generate (gfid); + + ret = dict_set_static_bin (xattr_req, "gfid-req", gfid, 16); + if (ret) { + errno = ENOMEM; + goto out; + } + ret = syncop_lookup (subvol, &loc, xattr_req, &ciatt, NULL, NULL); } @@ -203,6 +214,7 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent, goto out; inode = inode_link (loc.inode, loc.parent, component, &ciatt); +found: if (inode) inode_lookup (inode); if (iatt) @@ -220,7 +232,7 @@ out: int glfs_resolve_at (struct glfs *fs, xlator_t *subvol, inode_t *at, const char *origpath, loc_t *loc, struct iatt *iatt, - int follow) + int follow, int reval) { inode_t *inode = NULL; inode_t *parent = NULL; @@ -260,7 +272,12 @@ glfs_resolve_at (struct glfs *fs, xlator_t *subvol, inode_t *at, parent = inode; inode = glfs_resolve_component (fs, subvol, parent, - component, &ciatt); + component, &ciatt, + /* force hard lookup on the last + component, as the caller + wants proper iatt filled + */ + (reval || !next_component)); if (!inode) break; @@ -287,7 +304,7 @@ glfs_resolve_at (struct glfs *fs, xlator_t *subvol, inode_t *at, /* always recurisvely follow while following symlink */ - 1); + 1, reval); if (ret == 0) inode = inode_ref (sym_loc.inode); loc_wipe (&sym_loc); @@ -344,16 +361,16 @@ out: int glfs_resolve_path (struct glfs *fs, xlator_t *subvol, const char *origpath, - loc_t *loc, struct iatt *iatt, int follow) + loc_t *loc, struct iatt *iatt, int follow, int reval) { int ret = -1; if (origpath[0] == '/') ret = glfs_resolve_at (fs, subvol, NULL, origpath, loc, iatt, - follow); + follow, reval); else ret = glfs_resolve_at (fs, subvol, fs->cwd, origpath, loc, iatt, - follow); + follow, reval); return ret; } @@ -361,11 +378,11 @@ glfs_resolve_path (struct glfs *fs, xlator_t *subvol, const char *origpath, int glfs_resolve (struct glfs *fs, xlator_t *subvol, const char *origpath, - loc_t *loc, struct iatt *iatt) + loc_t *loc, struct iatt *iatt, int reval) { int ret = -1; - ret = glfs_resolve_path (fs, subvol, origpath, loc, iatt, 1); + ret = glfs_resolve_path (fs, subvol, origpath, loc, iatt, 1, reval); return ret; } @@ -373,11 +390,11 @@ glfs_resolve (struct glfs *fs, xlator_t *subvol, const char *origpath, int glfs_lresolve (struct glfs *fs, xlator_t *subvol, const char *origpath, - loc_t *loc, struct iatt *iatt) + loc_t *loc, struct iatt *iatt, int reval) { int ret = -1; - ret = glfs_resolve_path (fs, subvol, origpath, loc, iatt, 0); + ret = glfs_resolve_path (fs, subvol, origpath, loc, iatt, 0, reval); return ret; } -- cgit